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Carbon use efficiency (CUE) describes how efficiently plants incorporate the carbon fixed during photosynthesis into biomass gain and can be calculated as the ratio between net primary production (NPP) and gross primary production (GPP). In this work, annual CUE has been obtained from annual GPP and NPP MODIS products for the peninsular Spain study area throughout eight years. CUE is spatially and temporally analyzed in terms of the vegetation type and annual precipitation and annual average air temperature. Results show that dense vegetation areas with moderate to high levels of precipitation present lower CUE values, whereas more arid areas present the highest CUE values. However, the temperature effect on the spatial variation of CUE is not well characterized. On the other hand, inter-annual variations of CUE of different ecosystems are discussed in terms of inter-annual variations of temperature and precipitation. It is shown that CUE exhibited a positive correlation with precipitation and a negative correlation with temperature in most ecosystems. Thus, CUE decreases when the ecosystem conditions change towards aridity.

América latina muestra una diversidad abrumadora, en todos los sentidos, de espacios protegidos (EP): difieren en el tamaño, clima, hábitat, administración y metas, número y tipos de personal y ambiente sociocultural. En la actualidad estos espacios ya no pueden ser percibidos como lugares aislados de la realidad sociocultural que los rodea, con el único propósito de preservar el patrimonio natural. La investigación (indagación) científica debería jugar un papel clave en el manejo y función más integral e integrada del EP latinoamericano en su contexto paisajístico, tanto el biológico como el sociocultural. La indagación científica con fines básicos o aplicados no debe restringirse a los investigadores profesionales y sus estudiantes. El personal del EP y los pobladores del mismo EP y la matriz semi natural circundante (campesinos e indígenas) también son muy capaces de emplear las herramientas de la investigación. Presentamos estudios de caso desde las historias incompletas de los EP de Argentina, Cuba y Colombia hasta la historia casi completa de un EP boliviano. Muchas historias todavía son incompletas por la falta de recursos o de interés administrativo, o por el ambiente de paternalismo.

Few studies have examined diabetes impact on total joint arthroplasty (TJA) outcomes, with variable findings. We investigated the association between diabetes and post-TJA physical function and pain, examining whether diabetes impact differs by sex and BMI. Patient sample completed questionnaires within 3 months prior to hip or knee TJA for osteoarthritis (OA) and 1-year post-surgery. Surgical 'non-response' was defined as < 30% improvement in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain and physical function at 1-year. Two adjusted logistic regression models were estimated: (1) excluding, (2) including an interaction between diabetes, sex and BMI. The sample (626 hip, 754 knee) was 54.9% female, had mean BMI of 30.1, 13.0% reported diabetes. In adjusted models excluding an interaction, diabetes was not associated with non-response. However, a significant 3-way interaction (physical function: p = 0.003; pain: p = 0.006) between diabetes, sex, and BMI was found and was associated with non-response: non-response probability increased with increasing BMI in men with diabetes, but decreased with increasing BMI in women in diabetes. Findings suggest uncertainty in diabetes impact may be due to differential impacts by sex and BMI. A simple consideration of diabetes as present vs. absent may not be sufficient, with implications for the large TJA population., (© 2024. The Author(s).)

Objective: To assess the impact of diabetes on physical and mental health status, as well as patient satisfaction, one-year following knee and hip total joint arthroplasty (TJA) for osteoarthritis (OA)., Methods: Participants were 626 hip and 754 knee TJA patients. Pre-surgery data were collected on socio-demographics and health status. The 12-item Short Form Health Survey (SF-12) was collected pre- and one year post-surgery, and physical (PCS) and mental component (MCS) summary scores computed. One-year patient satisfaction was also recorded. Four regression models tested the effect of diabetes on: 1) PCS change score; 2) MCS change score; 3) achieving minimal clinically important improvement (MCII) on PCS; and 4) patient satisfaction ('Somewhat or Very Satisfied' vs. 'Somewhat or Very Dissatisfied'). An interaction between surgical joint and diabetes was tested in each model., Results: Self-reported diabetes prevalence was 13.0% (95% CI: 11.2%-14.7%) and was more common in knee 16.1% (95% CI: 13.4%-18.7%) than hip 9.3% (95% CI: 7.0%-11.5%) patients. In adjusted analyses, change scores were 2.3 units less on the PCS for those with diabetes compared to those without (p = 0.005). Patients with diabetes were about half as likely to achieve MCII as patients without diabetes (p = 0.004). Diabetes was not significantly associated with satisfaction or changes in MCS scores. Diabetes effects did not differ by surgical joint., Conclusions: Findings support that diabetes has a negative impact on improvements in physical health after TJA. Considering the growing prevalence of OA and diabetes in the population, our findings support the importance of perioperative screening and management of diabetes in patients undergoing TJA., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Power et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: The characterization and influence of preoperative health care use on quality-of-care indicators (e.g., readmissions) has received limited attention in populations with musculoskeletal disorders. The purpose of this study was to characterize preoperative health care use and examine its effect on quality-of-care indicators among patients undergoing elective surgery for osteoarthritis., Methods: Data on health care use for 124,750 patients with elective surgery for osteoarthritis in Ontario, Canada, from April 1, 2015 to March 31, 2018 were linked across health administrative databases. Using total health care use one-year previous to surgery, patients were grouped from low to very high users. We used Poisson regression models to estimate rate ratios, while examining the relationship between preoperative health care use and quality-of-care indicators (e.g., extended length of stay, complications, and 90-day hospital readmissions). We controlled for covariates (age, sex, neighborhood income, rural/urban residence, comorbidities, and surgical anatomical site)., Results: We found a statistically significant trend of increasing worse outcomes by health care use gradients that persisted after controlling for patient demographics and comorbidities. Findings were consistent across surgical anatomical sites. Moreover, very high users have relatively large numbers of visits to non-musculoskeletal specialists., Conclusions: Our findings highlight that information on patients' preoperative health care use, together with other risk factors (such as comorbidities), could help decision-making when benchmarking or reimbursing hospitals caring for complex patients undergoing surgery for osteoarthritis., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Objective: In osteoarthritis (OA) research, disability is largely studied within the context of activities of daily living. Broader consequences for social participation are often overlooked. In prior work, instrumental supports received and their perceived availability were shown to play a role in the maintenance of social participation. Two indicators of social participation were identified, diversity and intensity. The current study extends the findings from this prior cross-sectional work by examining these relationships longitudinally., Methods: Data are from the baseline and 3-year follow-up questionnaires of the Canadian Longitudinal Study on Aging, a population-based study of people ages 45-85 years at baseline. The sample was restricted to those who at baseline reported a doctor diagnosis of OA (n = 4104). Using structural equation modeling, latent variables were derived at each time point for activity limitations, instrumental supports perceived and received, and social participation diversity and intensity. Longitudinal factorial invariance was assessed. Model covariates included age, sex, education, income, marital status, smoking status, obesity, and number of chronic conditions., Results: For all latent variables, strong factorial longitudinal invariance was found. Activity limitations increased over time. Greater baseline social participation intensity was associated with increases in later intensity and diversity. Increasing activity limitations were associated with decreases in social participation and with increasing receipt of instrumental supports; they were not associated with changes in perceived availability of supports. However, increasing perceived availability was positively associated with social participation intensity., Conclusions: With a goal of increasing social participation, findings suggest a focus on interventions to reduce activity limitations in OA is necessary. Findings additionally highlight an important role for perceived availability of instrumental supports in maintaining or improving social participation in OA, in addition to current social participation, particularly intensity, for future social participation status., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Perruccio et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Objective: To highlight some important findings from osteoarthritis (OA) epidemiology and therapy research undertaken over the past year., Methods: Search of MEDLINE and EMBASE databases between April 1, 2022 to March 3, 2023 using "exp *Osteoarthritis/" as the preliminary search term. The search was limited to articles published in English and including human subjects. Final inclusions were based on perceived importance and results that may inform improved identification of risk factors or OA treatments, as well as OA subgroups of potential relevance to risk factors or treatment approaches., Results: 3182 studies were screened, leaving 208 eligible for inclusion. This narrative review of thirty-three selected studies was arranged into: a) OA predictors - population-based studies, b) Specific predictors of OA and OA outcome; c) Intra-articular injections, and d) OA phenotypes. There was some suggestion of sex differences in predictors of incidence or outcomes. Body mass index changes appear largely to affect knee OA outcomes. Evidence points to a lack of benefit of viscosupplementation in knee OA; findings were variable for other injectables. Studies of OA phenotypes reveal potentially relevant clinical and pathophysiological differences., Conclusions: Identifying risk factors for the incidence/progression of OA represents an ongoing and important area of OA research. Sex may play a role in this understanding and bears consideration and further study. For knee injectables other than viscosupplementation, additional high-quality trials appear warranted. Continued investigation and application of phenotyping across the OA disease, illness and care spectrum may be key to developing disease-modifying agents and their appropriate selection for individuals., (Copyright © 2023 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.)

Objective: To investigate the use and trends of virtual care in ophthalmology and examine associated factors in a universal health care system during the COVID-19 pandemic in 2020., Design: Cross-sectional study., Participants: Ontarians eligible for the Ontario Health Insurance Plan., Methods: We used physician billing data from 2017-2020 to describe the use of virtual versus in-person care. We used logistic regression to examine factors associated with virtual care use., Results: The uptake of ophthalmic virtual visits increased immediately following the government's directive to ramp down clinic activities and institution of a new virtual fee code (17.6%), peaked 2 weeks later (55.8%), and decreased immediately after the directive was lifted (24.2%). In March-December 2020, virtual visits were higher in female (11.6%) versus male (10.3%) patients and in patients <20 years of age (16.4%) and 20-39 years of age (12.3%) versus those aged 40-64 years (10.8%) and 65+ years (10.6%). Patients residing in the poorest/poorer neighbourhoods (10.9%) had similar use as their counterparts (11.1%). Patients with an acute infectious disease (14.2%) or nonurgent diagnosis (16.2%) had the highest use. Those with retinal disease had the lowest use (4.2%). Female ophthalmologists (15.4%) provided virtual care more often than male ophthalmologists (9.9%). Ophthalmologists aged 60-69 years (13.1%) provided virtual care more often than any other age groups (<40 years: 11.3%; 40-49 years: 11.0%; 50-59 years: 10.0%; and 70+ years: 7.7%). Multiple logistic regression models revealed similar results., Conclusion: Virtual care in ophthalmology increased significantly during the initial phase of the pandemic and decreased thereafter. There were significant variations in virtual care use by patient and ophthalmologist characteristics., (Copyright © 2022 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved.)

Objective: To assess the volume of deferred ophthalmic surgeries in Ontario associated with the COVID-19 pandemic from March to December 2020 and suggest strategies and time required to clear the backlog., Design: Cross-sectional study., Participants: Ontarians eligible for the Ontario Health Insurance Plan in 2017-2020., Methods: Backlog and clearance time for ophthalmic surgeries associated with the COVID-19 pandemic were estimated from time-series forecasting models and queuing theory., Results: From March 16 to December 31, 2020, the estimated ophthalmic surgical backlog needing operating rooms was 92,150 surgeries (95% prediction interval, 71,288-112,841). Roughly 90% of the delayed surgeries were cataract surgeries, and a concerning 4% were retinal detachment surgeries. Nearly half the provincial backlog (48%; 44,542 of 92,150) was in patients from the western health region. In addition, an estimated 23,755 (95% prediction interval, 14,656-32,497) anti-vascular endothelial growth factor injections were missed. Estimated provincial clearance time was 248 weeks (95% CI, 235-260) and 128 weeks (95% CI, 121-134) if 10% and 20% of operating room surgical capacity per week were added, respectively, based on the weekly ophthalmic surgical volume in 2019., Conclusions: Ontario data demonstrate that the magnitude of the ophthalmic surgical backlog in 2020 alone raises serious concerns for meeting the ophthalmic surgical needs of patients. As the pandemic continues, the accrued backlog size is likely to increase. Planning and actions are needed urgently to better manage the collateral impacts of the pandemic on the ophthalmic surgical backlog., (Copyright © 2022 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved.)

Objectives: Increased use of opioids and their associated harms have raised concerns around prescription opioid use for pain management following surgery. We examined trends and patterns of opioid prescribing following elective orthopaedic surgery., Design: Population-based study., Setting: Ontario, Canada., Participants: Ontario residents aged 66+ years who had elective orthopaedic surgery from April 2004 to March 2018., Primary and Secondary Outcome Measures: Postoperative opioid use (short term: within 90 days of surgery, prolonged: within 180 days and chronic: within 1 year), specific opioids prescribed, average duration (days) and amount (morphine milligram equivalents) of the initial prescription by year of surgery., Results: We included 464 460 elective orthopaedic surgeries in 2004/2005-2017/2018: 80% of patients used opioids within 1 year of surgery-25.1% were chronic users. There was an 8% increase in opioid use within 1 year of surgery, from 75.1% in 2004/2005 to 80.9% in 2017/2018: a 29% increase in short-term use and a decline in prolonged (9%) and chronic (22%) use. After 2014/2015, prescribed opioid amounts initially declined sharply, while the duration of the initial prescription increased substantially. Across categories of use, there was a steady decline in coprescription of benzodiazepines and opioids., Conclusions: Most patients filled opioid prescriptions after surgery, and many continued filling prescriptions after 3 months. During a period of general increase in awareness of opioid harms and dissemination of guidelines/policies aimed at opioid prescribing for chronic pain, we found changes in prescribing practices following elective orthopaedic surgery. Findings illustrate the potential impact of guidelines/policies on shaping prescription patterns in the surgical population, even in the absence of specific guidelines for surgical prescribing., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background Context: There is significant variability in minimal clinically important difference (MCID) criteria for lumbar spine surgery that suggests population and primary pathology specific thresholds may be required to help determine surgical success when using patient reported outcome measures (PROMs)., Purpose: The purpose of this study was to estimate MCID thresholds for 3 commonly used PROMs after surgical intervention for each of 4 common lumbar spine pathologies., Study Design/setting: Observational longitudinal study of patients from the Canadian Spine Outcomes and Research Network (CSORN) national registry., Patient Sample: Patients undergoing surgery from 2015 to 2018 for lumbar spinal stenosis (LSS; n = 856), degenerative spondylolisthesis (DS; n = 591), disc herniation (DH; n = 520) or degenerative disc disease (DDD n = 185) were included., Outcome Measures: PROMs were collected presurgery and 1-year postsurgery: the Oswestry Disability Index (ODI), and back and leg Numeric Pain Rating Scales (NPRS). At 1-year, patients reported whether they were 'Much better'/'Better'/'Same'/'Worse'/'Much worse' compared to before their surgery. Responses to this item were used as the anchor in analyses to determine surgical MCIDs for benefit ('Much better'/'Better') and substantial benefit ('Much better')., Methods: MCIDs for absolute and percentage change for each of the 3 PROMs were estimated using a receiving operating curve (ROC) approach, with maximization of Youden's index as primary criterion. Area under the curve (AUC) estimates, sensitivity, specificity and correct classification rates were determined. All analyses were conducted separately by pathology group., Results: MCIDs for ODI change ranged from -10.0 (DDD) to -16.9 (DH) for benefit, and -13.8 (LSS) to -22.0 (DS,DH) for substantial benefit. MCID for back and leg NPRS change were -2 to -3 for each group for benefit and -4.0 for substantial benefit for all groups on back NPRS. MCID estimates for percentage change varied by PROM and pathology group, ranging from -11.1% (ODI for DDD) to -50.0% (leg NPRS for DH) for benefit and from -40.0% (ODI for DDD) to -66.6% (leg NPRS for DH) for substantial benefit. Correct classification rates for all MCID thresholds ranged from 71% to 89% and were relatively lower for absolute vs percent change for those with high or low presurgical scores., Conclusions: Our findings suggest that the use of generic MCID thresholds across pathologies in lumbar spine surgery is not recommended. For patients with relatively low or high presurgery PROM scores, MCIDs based on percentage change, rather than absolute change, appear generally preferable. These findings have applicability in clinical and research settings, and are important for future surgical prognostic work., Competing Interests: Declarations of Competing Interest One or more of the authors declare financial or professional relationships on ICMJE-TSJ disclosure forms., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

Introduction: By adhering to host cells and colonizing tissues, bacterial pathogens can successfully establish infection. Adhesion is considered the first step of the infection process and bacterial adhesion to anti-adhesive compounds is now seen as a promising strategy to prevent infectious diseases. Among the natural sources of anti-adhesive molecules, the membrane of milk fat globules (MFGs) is of interest because of its compositional diversity of proteins and glycoconjugates. However, few studies have focused on the bacterial molecules involved in MFG- mediated inhibition of bacterial adhesion to enterocytes., Methods: We used three pathogenic Shiga toxin-producing Escherichia coli (STEC) strains (O26:H11 str. 21765, O157:H7 str. EDL933, and O103:H3 str. PMK5) as models to evaluate whether STEC surface proteins are involved in the affinity of STEC for MFG membrane proteins (MFGMPs). The affinity of STEC for MFGMPs was assessed both indirectly by a natural raw milk creaming test and directly by an adhesion test. Mass spectrometry was used to identify enriched STEC proteins within the protein fraction of MFGMs. Bacterial mutants were constructed and their affinity to MFGs were measured to confirm the role of the identified proteins., Results: We found that free STEC surface proteins inhibit the concentration of the pathogen in the MFG-enriched cream in a strain-dependent manner. Moreover, the OmpA and FliC proteins were identified within the protein fraction of MFGMs. Our results suggest that FliC protein participates in STEC adhesion to MFGMPs but other STEC molecules may also participate., Discussion: For the first time, this study highlighted, the involvement of STEC surface proteins in the affinity for MFGs. The mechanism of STEC-MFG association is still not fully understood but our results confirm the existence of receptor/ligand type interactions between the bacteria and MFGs. Further studies are needed to identify and specify the molecules involved in this interaction. These studies should consider the likely involvement of several factors, including adhesion molecules, and the diversity of each STEC strain., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Bagel, Bouvier-Crozier, Canizares, Hamadou, Courcol, Lopez, Michel, Douellou and Sergentet.)

Objective: The objective of this study was to investigate a profile of cardiovascular disease (CVD) risk factors by sex among individuals with and without osteoarthritis (OA) and to consider single-site and multisite joint OA., Methods: Data were sourced from Cycle 1, Comprehensive Cohort, Canadian Longitudinal Study on Aging, a national sample of individuals ages 45 to 85 years. Systemic inflammatory/metabolic CVD risk factors collected were high-sensitivity C-reactive protein (hsCRP) level, high-density lipoprotein, triglycerides, total cholesterol, body mass index (BMI), systolic blood pressure, and hemoglobin A1c. Smoking history was also collected. Respondents indicated doctor-diagnosed OA in the knees, hips, and/or hands and were characterized as yes/no OA and single site/multisite OA. Individuals with OA were age- and sex-matched to non-OA controls. Covariates were age, sex, education, income, physical activity, timed up and go test findings, and comorbidities. A latent CVD risk variable was derived in women and men; standardized scores were categorized as follows: lowest, mid-low, mid-high, and highest risk. Associations with OA were quantified using ordinal logistic regressions., Results: A total of 6,098 respondents (3,049 with OA) had a median age of 63 years, and 55.8% were women. One-third of OA respondents were in the highest risk category versus one-fifth of non-OA respondents. Apart from BMI (the largest contributor in both sexes), hsCRP level (an inflammation marker) was predominant in women, and metabolic factors and smoking were predominant in men. Overall, OA was associated with worse CVD risk quartiles compared with non-OA. OA was increasingly associated with worse CVD risk quartiles with increasing risk thresholds among women with multisite OA, but not men., Conclusion: Findings suggest unique CVD risks by sex/multisite subgroups and point to a potentially important role for inflammation in OA over and above traditional CVD risk factors., (© 2021 American College of Rheumatology.)

Background: Canada's fee-for-service physician reimbursement system, where a set rate is provided for each service, suggests that a physician sex pay gap should not exist. However, recent evidence has questioned this presumption., Objectives: To characterize trends in demographics and billing, overall and by sex, for dermatologists compared to other medical and surgical specialty groups in Ontario, Canada., Methods: Using population-based data, analysis of physician billing and clinical activity from Ontario, Canada, over 27 years (1992-2018) was performed. Multilevel regression models were used to examine unadjusted and adjusted differences in payments between females and males over time, while controlling for age, distinct patients seen, patient visits, and full-time equivalent., Results: A total of 22 389 physicians were included in the analyses, including 381 dermatologists. The proportion of female dermatologists increased from 32% in 1992 to 46% in 2018. Dermatologists' median Ontario Health Insurance Plan (OHIP) payments were $415 340 (IQR: 285 630-566 580) in 1992 compared to $296 750 (IQR: 164 480-493 180) in 2018. Male dermatologists' OHIP payments were 20% more than their female counterparts across the entire study period. After adjusting for practice volumes, there was no significant pay gap amongst female and male dermatologists ( P = .42); however, the sex pay gap remained significant for the other specialty groups ( P < .001). From 1992 to 2018, dermatologists on average saw 19% fewer distinct patients per year and 15% fewer visits per patient., Conclusions: The overall sex pay gap within medical dermatology can be attributed to differences in practice patterns, whereas the sex pay gap remained significant in the other specialty groups.

Objective: To examine the magnitude and costs of ambulatory primary care, specialist physician care, and hospital service use for musculoskeletal disorders (MSDs) in Canada's largest province, Ontario., Methods: Administrative health databases were analyzed for fiscal year 2013-2014 for adults aged ≥ 18 years, including data on physician services, emergency department (ED) visits, and hospitalizations. International Classification of Diseases diagnostic codes were used to identify MSD services. A validated algorithm was used to estimate direct medical costs. Person-visit rates and numbers of persons and visits were tabulated by care setting, age, sex, and physician specialty. Data were examined for all MSDs combined, as well as for specific diagnostic groupings., Results: Overall, 3.1 million adult Ontarians (28.5%) made over 8 million outpatient physician visits associated with MSDs. These included 5.6 million primary care visits. MSDs accounted for 560,000 (12.3%) of all adult ED visits. Total costs for MSD-related care were $1.6 billion, with 12.6% of costs attributed to primary care, 9.2% to specialist care, 8.6% to ED care, 8.5% to day surgery, and 61.2% associated with inpatient hospitalizations. Costs due to arthritis accounted for 40% of total MSD care costs ($639 million). MSD-related imaging costs were $169 million, yielding a total cost estimate of $1.8 billion for MSDs overall., Conclusion: MSDs place a significant and costly burden on the healthcare system. Health system planning needs to consider the large and escalating demand for care to reduce both the individual and population burden., (Copyright © 2022 by the Journal of Rheumatology.)

Background: Patient satisfaction is an important indicator used to monitor quality of care and outcomes after spine surgery., Objective: To examine the complex relationship between preoperative expectations, fulfillment of expectations, postsurgical outcomes, and satisfaction after spine surgery., Methods: In this national study of patients undergoing elective surgery for degenerative spinal conditions from the Canadian Spine Outcomes and Research Network Registry, we used logistic regression to examine the relationships between patient satisfaction with surgery (1-5 scale), preoperative expectation score (0 = none to 100 = highest), fulfillment of expectations, and disability and pain improvement., Results: Fifty-eight percent of patients were extremely satisfied, and 3% were extremely dissatisfied. Expectations were variable and generally high (mean 79.5 of 100) while 17.3% reported that none of their expectations were met, 49.8% reported that their most important expectation was met, and 32.9% reported that their most important expectation was not met but others were. The results from the fully adjusted ordinal logistic model for satisfaction indicate that satisfaction was higher among patients with higher preoperative expectations (odds ratio [OR] [95% CI]: 1.11, [1.04-1.19]), reporting important improvements in disability (OR [95% CI]: 2.52 [1.96-3.25]) and pain (OR [95% CI]: 1.64 [1.25-2.15]) and reporting that expectations were fulfilled (OR = 80.15, for all expectations were met). The results were similar for lumbar and cervical patients., Conclusion: Given the dominant impact of expectation fulfillment on satisfaction level, there is an opportunity for improving overall patient satisfaction by specifically assessing and mitigating the potential discrepancies between patients' preoperative expectations and likely surgical outcomes. The findings are likely relevant across elective surgical populations., (Copyright © 2022 The Author(s). Published by Wolters Kluwer Health, Inc on behalf of Congress of Neurological Surgeons.)

Objective: To understand differences between people with arthritis who do not know their type (DK) compared to those reporting osteoarthritis (OA) or inflammatory and autoimmune types of arthritis (IAA), including the receipt of appropriate health care, information, and services., Methods: Analysis of the Survey on Living with Chronic Disease in Canada-Arthritis Component. Respondents aged ≥20 years with health professional-diagnosed arthritis (n = 4,385) were characterized as reporting DK, OA or IAA. Variables: arthritis characteristics (duration, number and site of joints affected), arthritis impact (current pain and fatigue, difficulty in sleeping and daily activities, impact on life), health (self-rated general and mental health, life stress), arthritis management strategies (seeing health professionals, medication use, assistive devices, receipt of arthritis information, self-management activities). Multinomial logistic and log-Poisson regressions were used, as appropriate, to compare the DK to the OA and IAA groups., Results: In this arthritis sample, 44.2% were in the DK group, 38.3% reported OA and 17.5% reported IAA. Those in the DK group were more likely to be younger, have low income, low education, and be of non-white cultural background compared to those with OA. There were no significant differences in arthritis impact, but the DK group was less likely to have received information on, or have used, arthritis management strategies., Conclusions: The sociodemographic characteristics of the DK group suggest they likely have lower health literacy. They were less likely to have accessed health care and other support services, indicating this is an important group for health education, both for individuals with arthritis and health care providers., Competing Interests: The authors have declared that no competing interests exist.

Background: The proportion of women entering medicine has increased in recent years, and understanding the different practice patterns of female and male family physicians (FPs) will provide important information for health workforce planning. We sought to evaluate differences by sex in the supply, payments and clinical activity among FPs in Ontario., Methods: We conducted a cohort study using claims data from the Ontario Health Insurance Plan. We included all Ontario FPs who submitted claims from 1992 to 2018. We analyzed data using regression analyses for our outcomes of yearly number of FPs, payments, patient visits and distinct patients., Results: The number of practising FPs increased from 10 370 in 1992 to 14 329 in 2018, with an annual increase of 155 female FPs and 13 male FPs. In 2018, male FPs outnumbered female FPs by 1159. Among male FPs, 32.7% worked less than 1 full-time equivalent (FTE) position, 18.1% worked 1 FTE and 49.2% worked more than 1 FTE, with little change over the 27-year study period. Among female FPs, the percentage of those who worked less than 1 FTE position decreased over time (58.6% in 1998 to 48.3% in 2015), those who worked 1 FTE was stable (22.2%-24.3%) and those who worked more than 1 FTE increased (18.7% in 1998 to 28.0% in 2017). Yearly payments were higher for male FPs than female FPs by 40%-60% overall and by 10%-20% in FPs who worked more than 1 FTE. For FPs who worked 1 FTE or less than 1 FTE, both sexes had similar payment amounts (from 2005-2018). For FPs who worked 1 FTE, female FPs were less likely to receive payments from fee-for-service after 2004, and had 550 fewer visits and 121 fewer patients annually than male FPs., Interpretation: In Ontario, there are differences by sex in FP supply, payments, percentages of FTE groups, number of patient visits and number of distinct patients. Health administrators should be mindful of these differences when considering FP workforce plans to ensure a stronger primary health care system, with adequate health care delivery for the population., Competing Interests: Competing interests: None declared., (© 2022 CMA Impact Inc. or its licensors.)

BACKGROUND: How changes in recommendations for the use of knee arthroscopy have influenced real-world practice remains unclear. We assessed temporal trends in knee arthroscopy volume, costs, and rates of progression to knee arthroplasty following arthroscopy in Ontario, Canada. METHODS: We used diagnostic codes from population-based administrative databases from Ontario, Canada, to identify patients who underwent knee arthroscopy from April 1, 2004 to March 31, 2019. We calculated arthroscopy volume, costs, and rates of progression to knee arthroplasty within 1, 2, and 5 years following arthroscopy. RESULTS: A total of 408,040 arthroscopy procedures were included. The number of procedures declined 8.9% from 24,070 in 2004/2005 to 21,930 in 2018/2019. The volume of arthroscopy for osteoarthritis declined by 77.9% between 2007/2008 and 2018/2019. For degenerative meniscus disorders, the volume increased by 57.6% between 2004/2005 and 2013/2014, and then declined by 34.6% between 2013/2014 and 2018/2019. Among patients with osteoarthritis, rates of progression to knee arthroplasty were 3.8%, 9.6%, and 16.0%, at 1, 2, and 5 years, respectively, compared with rates among patients with degenerative meniscal disorders, which were 1.6%, 4.1%, and 7.3% at 1, 2, and 5 years, respectively. Over this period, progression to knee arthroplasty rates declined across diagnosis groups. These trends remained after adjusting for patient, surgeon, and hospital characteristics. CONCLUSIONS: In Ontario, Canada, utilization of knee arthroscopy declined between 2004/2005 and 2018/2019, with a concomitant decline in the rates of progression to knee arthroplasty within 1 to 5 years. Among the possible interpretations, our data are consistent with the hypothesis that clinical practice evolved as evidence-based recommendations against the use of knee arthroscopy for degenerative diagnoses were promulgated. (Funded by the Toronto General and Western Hospital Foundation through the University Health Network–Schroeder Arthritis Institute.)

Background Context: The Oswestry Disability Index (ODI) is the most commonly used outcome measure of functional outcome in spine surgery. The ability of the ODI to differentiate pain related functional limitation specifically related to degenerative lumbar spinal stenosis (LSS) is unclear., Purpose: The purpose of this study was to determine the ability of the functional subsections of the ODI to differentiate the specific patient limitation(s) from symptomatic LSS and the functional impact of surgery., Study Design: Analysis of prospectively collected data from the Canadian Spine Outcomes and Research Network (CSORN)., Patient Sample: A total of 1,497 lumbar spinal stenosis patients with a dominant complaint of neurogenic claudication, radiculopathy or back pain were identified in the CSORN registry., Outcome Measures: The ODI questionnaire version 2.0 was assessed as an outcome measure., Methods: The difference at baseline and the pre-to-post (1-year) surgical change of the ODI individual questions was assessed. Analysis of variance, two-tailed paired sample Student t test were used for statistical analysis. Cohen d was used as an index of effect size, defined as "large" when d ≥0.8., Results: The mean age at surgery was 65 (±11) years and (50.8%) of the patients were female. Preoperatively, highest functional limitations were noted for standing, lifting, walking, pain intensity and social life (mean 3.2, 2.9, 2.5, 2.9, 2.5 respectively). At 1-year follow-up, overall there was a significant improvement in all individual questions and the overall ODI (all p<.001), with similar patterns seen for each dominant complaint. The greatest effect of surgery was noted in the walking, social life and standing domains (all d≥0.81), while personal care, sitting and lifting showed the least improvement (all d≤0.51). In subgroup analyses, the overall ODI baseline scores and subsection limitations were statistically significantly higher in females, those without degenerative spondylolisthesis and those undergoing fusion, although these differences were not considered clinically significant. Preoperative differentiation of LSS specific functional limitation and postoperative changes in all subgroups was similar to the overall LSS cohort., Conclusions: The results of this study support the ability of the ODI to differentiate the self-reported pain related functional effects of neurogenic claudication, radiculopathy or back pain from LSS and changes associated with surgical intervention. Disaggregated use of the ODI could be a simple tool to aid in preoperative education regarding specific areas of pain related dysfunction and potential for improvement with LSS surgery., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Objective: To examine sex differences in Ontario Health Insurance Plan (OHIP) payments from 1992 to 2018., Design: Population-based observational study., Participants: Ophthalmologists submitting claims to OHIP from 1992 to 2018., Methods: Physician billing data over 27 years (1992-2018) were analyzed for yearly number of ophthalmologists, OHIP payments, distinct patients, and patient visits., Results: Yearly median OHIP payments to female ophthalmologists were less than to male ophthalmologists with a gap ratio of 0.55 in 1992 to 0.73 in 2018. Stratifying by full-time equivalent (FTE), there was little difference in median payments between males and females for 1 FTE. Median female-to-male payments ratio varied from 0.80 to 1.16 for <1 FTE and 1.14 to 0.84 for >1 FTE from 1992 to 2018. Among female ophthalmologists, 72.7% and 52.9% were <1 FTE and 11.4% and 19.2% were >1 FTE in 1992 and 2018, respectively. In comparison, for male ophthalmologists, 35.7% and 45.6% were <1 FTE and 43.4% and 45.6% were >1 FTE in 1992 and 2018, respectively. Overall, male ophthalmologists had more patients and patient visits than female ophthalmologists, but there was little difference between male and female ophthalmologists for 1 and >1 FTE. The results for <1 FTE varied by year., Conclusions: Overall, female ophthalmologists have lower OHIP payments compared with males, but there was little difference for those stratified to 1 FTE. This overall payments difference by sex is largely explained by the higher proportion of <1 FTE females, lower proportion of >1 FTE females, and higher payments for >1 FTE males., (Copyright © 2021 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved.)

Objective: The focus on disability in osteoarthritis (OA) has largely been on the ability to perform specific activities, which neglects the greater implications for social participation. We investigated the association between OA and social participation, considering activity limitations and instrumental supports as intervening variables in the association., Methods: Data were from 21,214 respondents, ages 45-85 years, from cycle 1 of the Canadian Longitudinal Study on Aging. The questionnaire elicited information regarding self-reported doctor-diagnosed OA, difficulty with 14 activities, perceived availability and receipt of instrumental supports, and 17 social participation activities. Structural equation modeling was used. The primary outcome was social participation, and the primary predictor was OA. The intervening variables included activity limitations, received instrumental supports, and perceived instrumental supports. Latent variables were developed for intervening and social participation variables. The covariates included age, sex, body mass index, income, education, smoking, and comorbidity count., Results: The mean age of the respondents was 63 years, 51% were female, and 26.5% reported having OA. Two distinct social participation indicators were identified, including social participation-diversity and social participation-intensity. When intervening variables were not considered, minimal/no association was found between OA and social participation. When intervening variables were considered, unique pathways linking OA and social participation were found. The overall negative association between activity limitations and social participation was partially direct and partially buffered by both receipt of and perceived availability of instrumental supports. In the absence of activity limitations, OA was associated with greater social participation., Conclusion: Enhanced social participation in people with OA who do not have activity limitations may reflect proactive steps taken by those with mild OA to maintain activity and social engagement. For those with activity limitations, findings highlight the need for interventions to mitigate limitations and draw particular attention to the importance of both provision and awareness of available instrumental supports in maintaining social participation., (© 2020, American College of Rheumatology.)

Introduction: Diversion of prescription opioid medication is a contributor to the opioid epidemic. Safe handling practices can reduce the risk of diversion. We aimed to understand: 1) if orthopaedic patients received instructions on how to safely handle opioids, 2) their typical storage/disposal practices, and 3) their willingness to participate in an opioid disposal program (ODP)., Methods: Cross-sectional study of adult orthopaedic patients who completed an anonymous survey on current or past prescription opioid use, instruction on handling, storage and disposal practices, presence of children in the household, and willingness to participate in an ODP. Frequencies and percentages of responses were computed, both overall and stratified by possession of unused opioids., Results: 569 respondents who reported either current or past prescription opioid use were analyzed. 44% reported receiving storage instructions and 56% reported receiving disposal instructions from a health care provider. Many respondents indicated unsafe handling practices: possessing unused opioids (34%), using unsafe storage methods (90%), and using unsafe disposal methods (34%). Respondents with unused opioids were less likely to report receiving handling instructions or using safe handling methods, and 47% of this group reported having minors or young adults in the household. Respondents who received storage and disposal instructions were more likely to report safe storage and disposal methods. Seventy-four percent of respondents reported that they would participate in an ODP., Conclusion: While many orthopaedic patients report inadequate education on safe opioid handling and using unsafe handling practices, findings suggest targeted education is associated with better behaviours. However, patients are willing to safely dispose of unused medication if provided a convenient option. These findings suggest a need to address patient knowledge and behavior regarding opioid handling to reduce the risk of opioid diversion., Competing Interests: I have read the journal’s policy and the authors of this manuscript have the following competing interests: Y. Raja Rampersaud has received royalties from Medtronic and holds investments in Arthur Health Corporation. This does not alter our adherence to PLOS ONE policies on sharing data and materials. All other co-authors have no competing interests to report.

Background: Little is known regarding long-term outcomes of patients hospitalized with COVID-19., Methods: We conducted a prospective study of 6-month outcomes of hospitalized COVID-19 patients. Patients with new neurological complications during hospitalization who survived were propensity score-matched to COVID-19 survivors without neurological complications hospitalized during the same period. The primary 6-month outcome was multivariable ordinal analysis of the modified Rankin Scale(mRS) comparing patients with or without neurological complications. Secondary outcomes included: activities of daily living (ADLs;Barthel Index), telephone Montreal Cognitive Assessment and Neuro-QoL batteries for anxiety, depression, fatigue and sleep., Results: Of 606 COVID-19 patients with neurological complications, 395 survived hospitalization and were matched to 395 controls; N = 196 neurological patients and N = 186 controls completed follow-up. Overall, 346/382 (91%) patients had at least one abnormal outcome: 56% had limited ADLs, 50% impaired cognition, 47% could not return to work and 62% scored worse than average on ≥1 Neuro-QoL scale (worse anxiety 46%, sleep 38%, fatigue 36%, and depression 25%). In multivariable analysis, patients with neurological complications had worse 6-month mRS (median 4 vs. 3 among controls, adjusted OR 1.98, 95%CI 1.23-3.48, P = 0.02), worse ADLs (aOR 0.38, 95%CI 0.29-0.74, P = 0.01) and were less likely to return to work than controls (41% versus 64%, P = 0.04). Cognitive and Neuro-QOL metrics were similar between groups., Conclusions: Abnormalities in functional outcomes, ADLs, anxiety, depression and sleep occurred in over 90% of patients 6-months after hospitalization for COVID-19. In multivariable analysis, patients with neurological complications during index hospitalization had significantly worse 6-month functional outcomes than those without., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Objective: Patients undergoing spine surgery generally have high expectations for improvement postoperatively. Little is known about how these expectations are affected by the diagnosis. The purpose of this study was to examine whether preoperative expectations differ based on diagnostic pathoanatomical patterns in elective spine surgery patients., Methods: Patients with common degenerative cervical/lumbar pathology (lumbar/cervical stenosis, lumbar spondylolisthesis, and cervical/lumbar disc herniation) who had given their consent for surgery were analyzed using the Canadian Spine Outcomes and Research Network (CSORN). Patients reported the changes they expected to experience postoperatively in relation to 7 separate items using a modified version of the North American Spine Society spine questionnaire. Patients were also asked about the most important item that would make them consider the surgery a success. Sociodemographic, lifestyle, and clinical variables were also collected., Results: There were 3868 eligible patients identified within the network for analysis. Patients with lumbar disc herniation had higher expectations for relief of leg pain compared with stenosis and lumbar degenerative spondylolisthesis cohorts within the univariate analysis. Cervical stenosis (myelopathy) patients were more likely to rank general physical capacity as their most important expectation from spine surgery. The multinomial regression analysis showed that cervical myelopathy patients have lower expectations for relief of arm or neck pain from surgery (OR 0.54, 0.34-0.88; p < 0.05). Patient factors, including age, symptoms (pain, disability, depression), work status, and lifestyle factors, were significantly associated with expectation, whereas the diagnoses were not., Conclusions: Patients with degenerative spinal conditions consenting for spine surgery have high expectations for improvement in all realms of their daily lives. With the exception of patients with cervical myelopathy, patient symptoms rather than diagnoses had a more substantial impact on the dimensions in which patients expected to improve or their most important expected change. Determination of patient expectation should be individualized and not biased by pathoanatomical diagnosis.

Background Context: In the lumbar spine osteoarthritis (LS-OA) population having surgery for lumbar spinal stenosis (LSS) symptoms, a significant proportion of patients experience limited benefit following the intervention. Thus, identifying contributing factors to this is important. Individuals with OA often have multiple joint symptoms, yet this has received limited attention in this population., Purpose: Document the occurrence of joint symptoms among patients undergoing surgery for LS-OA, and investigate the influence of these symptoms on disability postsurgery., Design: Prospective study of consecutive patients followed to 12-month postsurgery., Patient Sample: Patients undergoing surgery (decompression surgery, with or without fusion) for neurogenic claudication with or without back pain due to LSS with a primary pathology diagnosis of LS-OA., Outcomes Measures: Patient self-reported: Oswestry Disability Index (ODI), completed pre- and 12-month postsurgery; and, completed presurgery, age, sex, education, smoking, comorbid conditions, opioid use, short/long-term disability, depression and anxiety symptoms, back and leg pain intensity, presence of spondylolisthesis, procedure, prior spine surgery, and joints with arthritis and "pain/stiffness/swelling most days of the month" indicated on a homunculus (a joint site count was derived)., Assessments: Height and weight, used to calculate body mass index; timed-up-and-go performance-based test., Methods: Outcome of interest was achieving a clinically important improvement (CII) in ODI by 12-month postsurgery (yes/no). The association between joint site count and achieving a CII was examined by multivariable logistic regression analyses, adjusted for other measures., Results: In all, 165 patients were included. The mean age was 67 years (range: 44-90) and 47% were female. Seventy-seven percent reported 1+ joint site other than the back, 62% reported 2+, and 25% reported 4+. Among those achieving a CII, 21% had 4+ joint sites, compared with 31% among those not achieving a CII. Adjusted analyses: Increasing joint site count was associated with increasing risk (odds ratio [OR]: 1.32, 95% confidence interval [CI]: 1.05, 1.66) of not achieving a CII; for those with 4+ joints, adjusted probability of not achieving a CII exceeded 50%. Also associated with an increased risk of not achieving a CII was presurgery anxiety (OR: 2.97, 95% CI: 1.02, 8.65), opioid use (OR: 2.89, 95% CI: 1.07, 7.82), and worse back pain intensity score (OR: 1.27, 95% CI: 1.05, 1.53)., Conclusions: Multijoint involvement was highly prevalent in this LS-OA surgical sample. Its association with poorer postsurgery outcome supports a comprehensive approach to OA management and care. Knowledge of multijoint symptoms should inform patient education, shared decision-making, and recommendations for postsurgical rehabilitation and self-management strategies., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Axonal loss is the key pathological substrate of neurological disability in demyelinating disorders, including multiple sclerosis (MS). However, the consequences of demyelination on neuronal and axonal biology are poorly understood. The abundance of mitochondria in demyelinated axons in MS raises the possibility that increased mitochondrial content serves as a compensatory response to demyelination. Here, we show that upon demyelination mitochondria move from the neuronal cell body to the demyelinated axon, increasing axonal mitochondrial content, which we term the axonal response of mitochondria to demyelination (ARMD). However, following demyelination axons degenerate before the homeostatic ARMD reaches its peak. Enhancement of ARMD, by targeting mitochondrial biogenesis and mitochondrial transport from the cell body to axon, protects acutely demyelinated axons from degeneration. To determine the relevance of ARMD to disease state, we examined MS autopsy tissue and found a positive correlation between mitochondrial content in demyelinated dorsal column axons and cytochrome c oxidase (complex IV) deficiency in dorsal root ganglia (DRG) neuronal cell bodies. We experimentally demyelinated DRG neuron-specific complex IV deficient mice, as established disease models do not recapitulate complex IV deficiency in neurons, and found that these mice are able to demonstrate ARMD, despite the mitochondrial perturbation. Enhancement of mitochondrial dynamics in complex IV deficient neurons protects the axon upon demyelination. Consequently, increased mobilisation of mitochondria from the neuronal cell body to the axon is a novel neuroprotective strategy for the vulnerable, acutely demyelinated axon. We propose that promoting ARMD is likely to be a crucial preceding step for implementing potential regenerative strategies for demyelinating disorders.

Objective: The vast majority of published estimates of osteoarthritis (OA) burden are based on an OA diagnosis. These data are limited, as individuals often do not visit a physician until their symptoms are moderate to severe. This study compared individuals with an OA diagnosis to those with OA joint symptoms but without a diagnosis considering a number of sociodemographic and health characteristics. A further distinction was made between individuals with symptoms in one joint site and those with symptoms in multiple joint sites., Methods: Data are from 23 186 respondents aged 45 to 85 years from the first cycle of the Canadian Longitudinal Study on Aging. A multinomial logistic regression model examined the relationship between sociodemographic- and health-related characteristics and OA status (diagnosed OA, joint symptoms without OA, no OA or joint symptoms). In addition, logistic regression models assessed the relationship between OA status and usually experiencing pain and having some degree of functional limitation., Results: Twenty-one percent of respondents reported a diagnosis of OA, and 25% reported symptoms typical of OA but without an OA diagnosis. Other than being slightly younger, the characteristic profile of individuals with symptoms in two or more joint sites was indistinguishable from that of those with diagnosed OA., Conclusion: It may be warranted to consider OA-like multiple joint symptoms when deriving estimates of OA-attributed population health and cost burden., (© 2020 The Authors. ACR Open Rheumatology published by Wiley Periodicals, Inc. on behalf of American College of Rheumatology.)

Background: Understanding patient expectations is a critical component of patient-centered care; however, little is known about which expectation(s) are most important to patients as they relate to their sense of postoperative success., Purpose: To investigate patient's preoperative expectations of change in symptoms, function, and well-being resulting from surgical intervention and to examine the associations between sociodemographic, lifestyle, health status, and clinical characteristics with patient outcome expectations STUDY DESIGN: Observational cross-sectional study., Sample: Preoperative data from the Canadian Spine Outcomes and Research Network national registry of patients of patients (n=4,333) undergoing surgery for degenerative spinal conditions between 2012 and 2017., Outcome Measures: Patients reported their expectations as a result of the surgery (0 [no change], 1 [somewhat better], 2 [better] or 3 [much better]) for seven items: leg/arm pain, back/neck pain, independence in everyday activities, sporting activities/recreation, general physical capacity, frequency and quality of social contacts, and mental well-being. Patients also reported the single most important change expected., Methods: Data on demographic, lifestyles, health status, clinical factors, and reasons for having surgery were also collected. Factor analysis was used to examine the multidimensionality of expectations. Multivariate linear regression was used to examine factors associated with expectations., Results: Over 80% of patients reported expectation for improvements (at least somewhat better) in all items with the exception of social contacts (75.8%). Expectations are multidimensional; a two factor structure emerged indicating two expectation dimensions (pain relief and overall functional well-being). Two expectation scores were calculated corresponding to the two dimensions (0-100), with higher scores reflecting higher expectations. The mean±standard deviation pain relief expectation score was 78.5±24.7 and the mean overall functional well-being expectation score was 69.7±24.4. In multivariate analysis, the variables associated with these dimensions either differed or differed in degree of influence. For example, higher pain and disability scores, thoracolumbar location and diagnosis of spondylolisthesis were associated with higher expectations in both dimensions, while longer disease duration was only associated with lower overall functional well-being expectations. The top three most important expected change items were pain (improvement of leg or arm pain (29.1%)/improvement in back/neck pain (26.0%)), improvement in general capacity/function (21.0%), and improvement of independence in everyday activities (15.9%). Rankings of the most important expected change were similar across sociodemographic, lifestyle, health status, and clinical variables examined., Conclusions: Our findings highlight the need to identify and address specific individual expectations as part of the shared decision-making and presurgery education process., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Objective: To identify and describe back pain trajectory groups and to compare indicators of health status, medication, and health care use in these groups., Methods: A representative sample (n = 12,782) of the Canadian population was followed-up from 1994/1995 to 2010/2011. Participants were interviewed biannually and provided data on sociodemographic (e.g., education) and behavior-related (e.g., physical activity) factors, depression, comorbidities, pain, disability, medication use (e.g., opioids), and health care use (e.g., primary care visits). We used group-based trajectory analysis to categorize participants according to patterns in the course of their back pain during the 16-year follow-up period and compared indicators of pain, disability, medication, and health care use in the trajectory groups., Results: A total of 45.6% of the participants reported back pain at least once during follow-up. Of those, we identified 4 trajectories: persistent (18.0%), developing (28.1%), recovery (20.5%), and occasional (33.4%). The persistent and developing groups were characterized as having pain that prevented activities, disability, depression, and comorbidities. There were significant differences in the patterns of medication and health care use across the groups, with a general trend of most to least health care and medication use in the persistent, developing, recovering, and occasional groups. Those in the recovery group had an increasing trajectory reflecting opioid and antidepressant use., Conclusion: Approximately 1 in 5 people with back pain experience a persistent pain trajectory with an associated increase in pain, disability, and health care use. Further research is needed to determine whether the groups identified represent different diagnoses, which may provide insight into the selection of stratified treatment and aid in designing early prevention and management strategies in the population., (© 2018, American College of Rheumatology.)