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Charlotte R den Bakker,1 Arnout Jan de Beaufort,1 Friedo W Dekker,1,2 Belinda WC Ommering3 1Center for Innovation in Medical Education, Leiden University Medical Center, Leiden, the Netherlands; 2Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, the Netherlands; 3Research Centre for Learning and Innovation, Research Group on Research Competence, HU University of Applied Sciences Utrecht, Utrecht, the NetherlandsCorrespondence: Charlotte R den Bakker, Leiden University Medical Center, Center for Innovation in Medical Education, Hippocratespad 23, Zone V7-P, PO Box 9600, Leiden, 2333 ZD, the Netherlands, Tel + 31 71 52 998820, Email c.r.den_bakker@lumc.nlAbstract: Scholarly doctors require research knowledge and skills (Ausbildung), as well as an academic mindset, which includes curiosity, creativity, and critical thinking (Bildung). However, in contrast to knowledge and skills, summative assessment of the development of an academic mindset is not so easy in an objective and so-called ‘fair’ way. As a result, in practice, assessing knowledge and skills tends to dominate in scholarly development. In this perspective, we explore the issues that arise when we give priority to objective assessment of knowledge and skills in scholarly development to safeguard fairness and, consequently, standardize educational procedures and learning pathways. We argue that eventually this approach may even result in hampered development of a true academic mindset and can be considered unfair rather than fair. To solve this, perhaps we should go back to the core business of the university and in the tradition of founder of the modern university Von Humboldt focus on shaping an academic mindset (Bildung). To rebalance Ausbildung and Bildung in academic education, we should go beyond the assumption that objectivity is a prerequisite for achieving fairness in assessment. Shifting the focus from pure objectivity to both objectivity and subjectivity in assessment as well as learning pathways can assist in protecting fairness and, as a result, bring back Bildung to medical education to ensure future doctors to be true scholars.Keywords: scholars, research training, Bildung

Erzsébet Horváth-Puhó,1 Marit M Suttorp,2 Henrik Frederiksen,1,3 Tiny Hoekstra,2 Olaf M Dekkers,1,2 Lars Pedersen,1 Suzanne C Cannegieter,2 Friedo W Dekker,2 Henrik Toft Sørensen1 1Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark; 2Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, the Netherlands; 3Department of Haematology, Odense University Hospital, Odense, Denmark Introduction: Erythropoiesis-stimulating agent (ESA) treatment has been associated with an increased risk of venous thromboembolism (VTE) in patients with solid tumors and with an increased risk of cardiovascular events in patients with chronic kidney disease. The ESA-related risk in patients with hematological neoplasms remains unclear. We, therefore, aimed to assess the ESA-related risk of VTE, myocardial infarction (MI), and stroke in patients with multiple myeloma (MM) and myelodysplastic syndrome (MDS). Materials and methods: We conducted a population-based cohort study in Denmark, using medical databases to identify 2,114 MDS patients and 3,105 MM patients diagnosed in 2004–2013. Incidence rates per 1,000 person-years and hazard ratios (HRs) with 95% confidence intervals (CIs) for VTE, MI, and stroke associated with ESA treatment were computed. HRs were calculated in time-dependent Cox regression and adjusted for age, sex, MDS prognosis group, comorbidities, and treatments. Results: Incidence rates per 1,000 person-years for VTE, MI, and stroke were 10.8, 8.2, and 16.0 in MDS patients, and 21.9, 10.2 and 9.9 in MM patients without ESA treatment, respectively. MDS patients with ESA treatment had a 1.6-fold increased risk of MI (HR 1.60 [95% CI 0.90–2.86]) and an almost twofold increased risk of stroke (HR 1.94 [95% CI 1.28–2.94]). Adjusted HR for VTE was 1.04 (95% CI 0.57–1.89) compared with MDS patients without ESAs. In MM patients with ESAs compared with patients without ESAs, HRs were 1.41 (95% CI 0.96–2.08) for VTE, 1.23 (95% CI 0.68–2.20) for MI, and 1.63 (95% CI 0.96–2.77) for stroke. Conclusion: ESA use was associated with stroke in MDS patients. Among MM patients, ESA treatment was associated with a higher risk of all cardiovascular events, although all CIs included equivalence. Keywords: cohort study, epidemiology, erythropoietin, multiple myeloma, myelodysplastic syndromes, myocardial infarction, stroke, pulmonary embolism, venous thrombosis

Pauline WM Voskamp,1 Friedo W Dekker,1 Maarten B Rookmaaker,2 Marianne C Verhaar,2 Willem Jan W Bos,3 Merel van Diepen,1 Gurbey Ocak2 1Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, the Netherlands; 2Department of Nephrology and Hypertension, University Medical Center Utrecht, Utrecht, the Netherlands; 3Department of Nephrology, Sint Antonius Hospital, Nieuwegein, the Netherlands Purpose: A post hoc analysis of a recent trial on direct oral anticoagulants versus vitamin K antagonists showed that amongst patients with mildly decreased kidney function, use of vitamin K antagonists was associated with a greater decline in renal function than use of direct oral anticoagulants. Whether these vitamin K antagonist effects are the same in pre-dialysis patients is unknown. Therefore, the aim of this study was to investigate the association between vitamin K antagonist use and the rate of renal function decline and time until start of dialysis in incident pre-dialysis patients.Methods: Data from 984 patients from the PREdialysis PAtient REcord study, a multicenter follow-up study of patients with chronic kidney disease who started pre-dialysis care in the Netherlands (1999–2011), were analyzed. Of these patients, 101 used a vitamin K antagonist. Linear mixed models were used to compare renal function decline between vitamin K antagonist users and non-users. Cox proportional hazards models were used to estimate the HR with 95% CI for starting dialysis.Results: Vitamin K antagonist use was associated with an extra change in renal function of –0.09 (95% CI –1.32 to 1.13) mL/min/1.73 m2 per year after adjustment for confounding. The adjusted HR for the start of dialysis was 1.20 (95% CI 0.85 to 1.69) in vitamin K antagonist users, compared to non-users. Conclusion: In incident pre-dialysis patients, the use of vitamin K antagonists was not associated with an accelerated kidney function decline or an earlier start of dialysis compared to non-use. The lack of knowledge on the indication for vitamin K antagonist use could lead to confounding by indication. Keywords: coumarins, epidemiology, chronic kidney disease, glomerular filtration rate

Cynthia J Janmaat,1 Merel van Diepen,1 Cheyenne CE van Hagen,1 Joris I Rotmans,2 Friedo W Dekker,1 Olaf M Dekkers1,2 1Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, the Netherlands, 2Department of Internal Medicine, Leiden University Medical Center, Leiden, the Netherlands Purpose: Substantial heterogeneity exists in reported kidney function decline in pre-dialysis chronic kidney disease (CKD). By design, kidney function decline can be studied in CKD 3–5 cohorts or dialysis-based studies. In the latter, patients are selected based on the fact that they initiated dialysis, possibly leading to an overestimation of the true underlying kidney function decline in the pre-dialysis period. We performed a systematic review and meta-analysis to compare the kidney function decline during pre-dialysis in CKD stage 3–5 patients, in these two different study types. Patients and methods: We searched PubMed, EMBASE, Web of Science and Cochrane to identify eligible studies reporting an estimated glomerular filtration rate (eGFR) decline (mL/min/1.73 m2) in adult pre-dialysis CKD patients. Random-effects meta-analysis was performed to obtain weighted mean annual eGFR decline. Results: We included 60 studies (43 CKD 3–5 cohorts and 17 dialysis-based studies). The meta-analysis yielded a weighted annual mean (95% CI) eGFR decline during pre-dialysis of 2.4 (95% CI: 2.2, 2.6) mL/min/1.73 m2 in CKD 3–5 cohorts compared to 8.5 (95% CI: 6.8, 10.1) in dialysis-based studies (difference 6.0 [95% CI: 4.8, 7.2]). Conclusion: To conclude, dialysis-based studies report faster mean annual eGFR decline during pre-dialysis than CKD 3–5 cohorts. Thus, eGFR decline data from CKD 3–5 cohorts should be used to guide clinical decision making in CKD patients and for power calculations in randomized controlled trials with CKD progression during pre-dialysis as the outcome. Keywords: meta-analysis, systematic review, kidney function decline, dialysis, chronic kidney disease, pre-dialysis, CKD progression

Chava L Ramspek,1 Pauline WM Voskamp,1 Frans J van Ittersum,2 Raymond T Krediet,3 Friedo W Dekker,1 Merel van Diepen1 On behalf of the NECOSAD study group 1Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, 2Department of Nephrology, VU University Medical Center, 3Department of Nephrology, Academic Medical Center, Amsterdam, The Netherlands Objective: In medicine, many more prediction models have been developed than are implemented or used in clinical practice. These models cannot be recommended for clinical use before external validity is established. Though various models to predict mortality in dialysis patients have been published, very few have been validated and none are used in routine clinical practice. The aim of the current study was to identify existing models for predicting mortality in dialysis patients through a review and subsequently to externally validate these models in the same large independent patient cohort, in order to assess and compare their predictive capacities.Methods: A systematic review was performed following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. To account for missing data, multiple imputation was performed. The original prediction formulae were extracted from selected studies. The probability of death per model was calculated for each individual within the Netherlands Cooperative Study on the Adequacy of Dialysis (NECOSAD). The predictive performance of the models was assessed based on their discrimination and calibration.Results: In total, 16 articles were included in the systematic review. External validation was performed in 1,943 dialysis patients from NECOSAD for a total of seven models. The models performed moderately to well in terms of discrimination, with C-statistics ranging from 0.710 (interquartile range 0.708–0.711) to 0.752 (interquartile range 0.750–0.753) for a time frame of 1 year. According to the calibration, most models overestimated the probability of death.Conclusion: Overall, the performance of the models was poorer in the external validation than in the original population, affirming the importance of external validation. Floege et al’s models showed the highest predictive performance. The present study is a step forward in the use of a prediction model as a useful tool for nephrologists, using evidence-based medicine that combines individual clinical expertise, patients’ choices, and the best available external evidence. Keywords: external validation, prediction, nephrology, dialysis, mortality

Cynthia J Janmaat,1 Merel van Diepen,1 Raymond T Krediet,2 Marc H Hemmelder,3 Friedo W Dekker1 On behalf of the NECOSAD study group 1Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, 2Department of Nephrology, Academic Medical Center, Amsterdam, 3Department of Internal Medicine, Nefrovisie Foundation, Utrecht, Netherlands Purpose: Current clinical guidelines recommend to initiate dialysis in the presence of symptoms or signs attributable to kidney failure, often with a glomerular filtration rate (GFR) of 5–10 mL/min/1.73 m2. Little evidence exists about the optimal kidney function to start dialysis. Thus far, most observational studies have been limited by lead-time bias. Only a few studies have accounted for lead-time bias, and showed contradictory results. We examined the effect of GFR at dialysis initiation on survival in chronic kidney disease patients, and the role of lead-time bias therein. We used both kidney function based on 24-hour urine collection (measured GFR [mGFR]) and estimated GFR (eGFR). Materials and methods: A total of 1,143 patients with eGFR data at dialysis initiation and 852 patients with mGFR data were included from the NECOSAD cohort. Cox regression was used to adjust for potential confounders. To examine the effect of lead-time bias, survival was counted from the time of dialysis initiation or from a common starting point (GFR 20 mL/min/1.73 m2), using linear interpolation models. Results: Without lead-time correction, no difference between early and late starters was present based on eGFR (hazard ratio [HR] 1.03, 95% confidence interval [CI] 0.81–1.3). However, after lead-time correction, early initiation showed a survival disadvantage (HR between 1.1 [95% CI 0.82–1.48] and 1.33 [95% CI 1.05–1.68]). Based on mGFR, the potential survival benefit for early starters without lead-time correction (HR 0.8, 95% CI 0.62–1.03) completely disappeared after lead-time correction (HR between 0.94 [95% CI 0.65–1.34] and 1.21 [95% CI 0.95–1.56]). Dialysis start time differed about a year between early and late initiation. Conclusion: Lead-time bias is not only a methodological problem but also has clinical impact when assessing the optimal kidney function to start dialysis. Therefore, lead-time bias is extremely important to correct for. Taking account of lead-time bias, this controlled study showed that early dialysis initiation (eGFR >7.9, mGFR >6.6 mL/min/1.73 m2) was not associated with an improvement in survival. Based on kidney function, this study suggests that in some patients, dialysis could be started even later than an eGFR

Balancing immunosuppression to prevent rejection in solid organ transplant (SOT) recipients remains challenging. Torque teno virus (TTV), a commensal non‐pathogenic virus, has been proposed as marker of functional immunity: higher loads correspond to over‐immunosuppression, and lower loads to under‐immunosuppression. This review offers an overview of the current evidence of the association between TTV‐load and infection and rejection after SOT. A systematic literature search strategy, deposited in the PROSPERO registry, resulted in 548 records. After screening, 23 original and peer‐reviewed articles were assessed investigating the association between TTV‐load, infection and/or rejection in SOT. The Quality in Prognostic Studies (QUIPS)‐tool was used to assess the risk of bias. Meta‐analysis with random‐effects was performed on results with similar outcomes and exposure measures. Most of the included studies involved retrospective cohorts in which the TTV‐load was measured longitudinally, within the first 2 years post‐transplantation. Infection outcomes differed between studies and included viral, bacterial, parasitic and fungal infections. Rejection was defined by biopsy confirmation or initiation of rejection treatment. Twelve out of 16 studies reported an association between high TTV‐load and infections, whereas 13 out of 15 reported an association between low TTV‐load and rejection. Meta‐analysis showed an increased risk of infection (OR: 1.16, 95% CI: 1.03–1.32; HR: 1.05, 95% CI: 0.97–1.14) and a decreased risk of rejection (OR: 0.90, 95% CI: 0.87–0.94; HR: 0.74, 95% CI: 0.71–0.76) per 1 log TTV‐load increase. The qualitative assessment showed varying risks of bias in the included studies. This systematic review and meta‐analysis indicates that blood TTV‐load measured within the first 2 years after SOT is associated with the risk of infection or allograft rejection, although substantial risk of bias in the studies included warrant cautious interpretation. The results in this review provide a rationale for larger, prospective, studies into TTV as marker of infection and rejection after SOT. [ABSTRACT FROM AUTHOR]

BACKGROUND: Obesity is a risk factor for loss of kidney function in the general population, but it is unknown whether it proceeds to affect residual kidney function when patients require dialysis. Our aim was to study the effects of body mass index (BMI) on decline in kidney function and risk to develop anuria after initiation of dialysis therapy. STUDY DESIGN: Prospective cohort study. SETTING & PARTICIPANTS: 1,271 incident dialysis patients from 38 centers in The Netherlands participating in the Netherlands Cooperative Study on the Adequacy of Dialysis (NECOSAD) between 1997 and 2006. PREDICTOR: BMI assessed at 3 months after the initiation of dialysis therapy (baseline) and categorized into 4 groups: less than 20, 20 or greater to 25, 25 or greater to 30, and 30 or greater kg/m(2). OUTCOMES & MEASUREMENTS: The decrease in measured glomerular filtration rate (mGFR) was determined by means of linear mixed models and adjusted for age, sex, primary kidney disease, dialysis modality, smoking, cardiovascular disease, and normalized protein nitrogen appearance and additionally for proteinuria, blood pressure, and baseline mGFR. Cox regression analysis was used to calculate hazard ratios for the development of anuria. RESULTS: Patients had a mean age of 59 +/- 15 years, BMI of 24.8 +/- 4.1 kg/m(2), and mGFR of 4.7 +/- 3.3 mL/min. During 18 months of follow-up, the decrease in mGFR in patients with normal weight was 1.2 mL/min/y (95% confidence interval [CI], 0.7 to 1.6). Compared with those values, adjusted losses of mGFR were 0.4 mL/min/y (95% CI, 0.02 to 0.8) greater for overweight and 1.2 mL/min/y (95% CI, 0.5 to 1.8) greater for obese patients. In contrast, the decrease in underweight patients was 0.6 mL/min/y (-0.1 to 1.3) less. Anuria occurred in 297 patients; the risk was similar among BMI groups after adjustment for confounders and baseline diuresis. LIMITATIONS: Patients with missing BMI or mGFR values at baseline were excluded. CONCLUSION: Obesity is a strong risk factor for the decline in kidney function after initiation of dialysis therapy. Whether obese dialysis patients might benefit from a healthy weight reduction needs to be studied further. Copyright © 2009 National Kidney Foundation, Inc. [ABSTRACT FROM AUTHOR]

The present study explored illness perceptions of end stage renal disease (ESRD) patients on both haemodialysis (HD) and peritoneal dialysis (PD) treatment, and their associations with quality of life. Leventhal's self-regulation model (SRM) was used as a theoretical framework. Illness perceptions and quality of life were assessed with the IPQ-R and the SF-36 in 91 HD and 42 PD patients participating in the NECOSAD-study. Compared to HD patients, PD patients experienced more personal control and had a better understanding of the illness. Illness perceptions explained from 17 to 51% of the variance in quality of life scores. Perception of more symptoms, more consequences and lower personal control were associated with lower well-being. The concept of illness perceptions is useful in understanding the impact of ESRD and of dialysis treatment on quality of life. Interventions aimed at providing more knowledge about ESRD and dialysis, and provision of skills to coping with the illness and its consequences may improve quality of life in dialysis patients. [ABSTRACT FROM AUTHOR]

BACKGROUND: Self-rated health (SRH) has been shown to predict mortality in large community-based studies; however, large clinical-based studies of this topic are rare. We assessed whether an SRH item predicts mortality in a large sample of incident dialysis patients beyond sociodemographic, disease, and clinical measures and possible age interaction. STUDY DESIGN: Prospective cohort study. SETTING & PARTICIPANTS: 1,443 predominantly white patients from 38 dialysis centers in The Netherlands participating in the Netherlands Cooperative Study on the Adequacy of Dialysis-2 between 1997 and 2004. PREDICTOR: SRH score completed at 3 months after the start of dialysis therapy (baseline). OUTCOMES & MEASUREMENTS: Cox proportional hazards model estimated the association between SRH and all-cause mortality. Interaction of SRH with age (<65 and >/=65 years) was examined in an additive model. RESULTS: Mean age of patients was 59.6 +/- 14.8 years, with 61% men and 69% married/living together. Mean follow-up was 2.7 +/- 1.8 years. Deaths per SRH group in the multivariate analyses sample: excellent/very good (9 of 63 patients; 14.3%), good (148 of 473 patients; 31.3%), fair (194 of 508 patients; 38.2%), and poor (45 of 71 patients; 63.4%). Patients with poor, fair, or good health ratings had a greater mortality risk than those with excellent/very good health ratings (adjusted hazard ratio [HR(adj)], 3.56; 95% confidence interval [CI], 1.71 to 7.42; HR(adj), 2.09; 95% CI, 1.06 to 4.12; HR(adj), 1.87; 95% CI, 0.95 to 3.70, respectively) independent of a range of risk factors. No age interaction with SRH was found. LIMITATIONS: Although the SRH-mortality association remained strong despite extensive adjustments, unknown residual confounding could still exist. CONCLUSION: SRH is an independent predictor of mortality in incident dialysis patients. Patients with poor SRH in both age strata had a significantly increased risk of mortality even after controlling for demographic and clinical confounders. Patient self-assessment of health can be an invaluable and economical complement to clinical measures in risk assessment. Copyright © 2008 National Kidney Foundation, Inc. [ABSTRACT FROM AUTHOR]

BACKGROUND: The hypothesis of intrauterine origin of adult disease is debated. We tested whether intrauterine growth restriction is associated with later kidney function. STUDY DESIGN: Prospective cohort study. SETTING & PARTICIPANTS: 7,457 Norwegian adults aged 20 to 30 years participating in the population-based Nord Trøndelag Health Study (1995-1997) with data for birth weight, gestational age, and maternal and perinatal risk factors registered at the Medical Birth Registry of Norway. PREDICTOR: Birth weight expressed as an SD score (SDS) to adjust for gestational age and sex. Subjects with a birth weight SDS less than -2.0, -2.0 to -1.3, and -1.3 to 1.3 were defined as very small, small, and appropriate for gestational age, corresponding to less than the 3rd, 3rd to 10th, and 10th to 90th percentiles, respectively. OUTCOME & MEASUREMENTS: Kidney function estimated using the Cockcroft-Gault and isotope dilution mass spectrometry-traceable 4-variable Modification of Diet in Renal Disease (MDRD) Study equation. Values less than the sex-specific 10th percentile were defined as low-normal kidney function. RESULTS: Compared with men with birth weight appropriate for gestational age (n = 2,755), odds ratios for low-normal creatinine clearance (<100 mL/min) were 1.66 (95% confidence interval [CI], 1.16 to 2.37) if small for gestational age (n = 261) and 2.40 (95% CI, 1.46 to 3.94) if very small for gestational age (n = 101). Kidney function estimated using the MDRD Study equation gave similar results. Women (n = 3,126, 283, and 112, respectively) had odds ratios of 1.65 (95% CI, 1.17 to 2.35) and 2.00 (95% CI, 1.21 to 3.29) for low-normal creatinine clearance (<80 mL/min), whereas the association was not significant using the MDRD Study equation. Using linear regression, creatinine clearance decreased by 4.0 mL/min (95% CI, 3.3 to 4.6) in men and 2.9 mL/min (95% CI, 2.2 to 3.5) in women per 1-SDS decrease. Adjusting for possible confounders did not influence results. LIMITATIONS: Selection bias could be a problem because the participation rate was 49%, but there were no statistically significant differences between participants and nonparticipants regarding maternal and perinatal characteristics. Adjusting kidney function for body size can be a special problem in people with intrauterine growth restriction. CONCLUSIONS: Although effects were still small in young adulthood, intrauterine growth restriction was significantly associated with low-normal kidney function. The effect was weaker and less consistent in women compared with men. Copyright © 2008 National Kidney Foundation, Inc. [ABSTRACT FROM AUTHOR]

BACKGROUND: Premature birth and intrauterine growth restriction may increase the risk of developing renal disease at adult age. Renal function may already be impaired at young adult age. STUDY DESIGN: Cross-sectional study. SETTING & PARTICIPANTS: Very premature individuals (gestational age < 32 weeks) recruited from Project on Premature and Small for Gestational Age Infants and full-term-born controls (37 to 42 weeks) recruited from a children's hospital in Rotterdam, The Netherlands. All individuals were 20 years of age at the time of study. PREDICTORS: Gestational age and birth weight: premature and small for gestational age (SGA; n = 23), premature and appropriate for gestational age (n = 29), and controls (n = 30). OUTCOMES & MEASUREMENTS: Glomerular filtration rate (GFR), effective renal plasma flow (ERPF), and filtration fraction before and after renal stimulation with low-dose dopamine infusion and oral amino-acid intake. Urine albumin and renal ultrasound. RESULTS: Height, weight, kidney length and volume, GFR, and ERPF were significantly lower in the SGA group than in controls. After adjustment for body surface area, GFR did not differ significantly among groups. Mean ERPF was 71 mL/min/1.73 m(2) (95% confidence interval [CI], 3 to 139) less, but filtration fraction was only 1.3% (95% CI, -0.3 to 3.0) greater, in the SGA group than controls. Renal stimulation significantly increased GFR and ERPF and decreased filtration fraction in all groups. After renal stimulation, ERPF was 130 mL/min/1.73 m(2) (95% CI, 21 to 238) greater in the SGA group than controls, but GFR and filtration fraction did not differ significantly among groups. Microalbuminuria was present in 2 patients (8.7%) in the SGA group, but none in the appropriate-for-gestational-age group or controls. Renal function correlated with renal size. LIMITATIONS: Small sample size. CONCLUSIONS: Our findings do not fully support the hypothesis that preterm birth in combination with intrauterine growth restriction contributes to renal function alterations at young adult age. Larger studies are needed to evaluate this hypothesis. Copyright © 2007 by Elsevier Inc. [ABSTRACT FROM AUTHOR]

BACKGROUND: Increasing evidence indicates that adult body composition is associated with prenatal and infancy weight gain, but the relative importance of different time periods has not been elucidated. OBJECTIVE: The objective was to study the association between prenatal, early postnatal, and late infancy weight gain and body mass index (BMI), fat mass, and fat distribution in young adulthood. DESIGN: We included 403 men and women aged 19 y from a Dutch national prospective follow-up study who were born at <32 wk of gestation. BMI, waist circumference, and waist-to-hip ratio SD scores and subscapular-to-triceps ratio, percentage body fat, fat mass, and fat-free mass at age 19 y were studied in relation to birth weight SD scores, weight gain from preterm birth until 3 mo postterm (early postnatal weight gain), and weight gain from 3 mo until 1 y postterm (late infancy weight gain). RESULTS: Birth weight SD scores were positively associated with weight, height, BMI SD scores, and fat-free mass at age 19 y but not with fat mass, percentage body fat, or fat distribution. Early postnatal and late infancy weight gain were positively associated with adult height, weight, BMI, waist circumference SD scores, fat mass, fat-free mass, and percentage body fat but not with waist-to-hip ratio SD scores or subscapular-to-triceps ratio. CONCLUSIONS: In infants born very preterm, weight gain before 32 wk of gestation is positively associated with adult body size but not with body composition and fat distribution. More early postnatal and, to a lesser extent, late infancy weight gain are associated with higher BMI SD scores and percentage body fat and more Copyright © 2005 American Society for Clinical Nutrition [ABSTRACT FROM AUTHOR]

Background. So far, little attention has been paid to the value of dialysis adequacy for patients' quality of life (QL). Therefore we studied the impact of demographic, Clinical, and dialysis characteristics on physical symptoms and perceived QL. [ABSTRACT FROM PUBLISHER]

Background: As abnormal growth might be the first manifestation of undetected diseases, it is important to have accurate referral criteria and a proper diagnostic work-up. In the present paper we evaluate the diagnostic work-up in secondary health care according to existing consensus guidelines and study the frequency of underlying medical disorders.Methods: Data on growth and additional diagnostic procedures were collected from medical records of new patients referred for short stature to the outpatient clinics of the general paediatric departments of two hospitals (Erasmus MC - Sophia Children's Hospital, Rotterdam and Spaarne Hospital, Haarlem) between January 1998 and December 2002. As the Dutch Consensus Guideline (DCG) is the only guideline addressing referral criteria as well as diagnostic work-up, the analyses were based on its seven auxological referral criteria to determine the characteristics of children who are incorrectly referred and the adequacy of workup of those who are referred.Results: Twenty four percent of children older than 3 years were inappropriately referred (NCR). Of the correctly referred children 74-88% were short corrected for parental height, 40-61% had a height SDS <-2.5 and 21% showed height deflection (Delta HSDS < -0.25/yr or Delta HSDS < -1). In none of the children a complete detailed routine diagnostic work up was performed and in more than 30% no routine laboratory examination was done at all. Pathologic causes of short stature were found in 27 children (5%).Conclusion: Existing guidelines for workup of children with suspected growth failure are poorly implemented. Although poorly implemented the DCG detects at least 5% pathologic causes of growth failure in children referred for short stature. New guidelines for referral are required with a better sensitivity and specificity, wherein distance to target height should get more attention. The general diagnostic work up for short stature should include testing for celiac disease in all children and for Turner syndrome in girls. [ABSTRACT FROM AUTHOR]

In Europe there is considerable variation in mortality on renal replacement therapy (RRT). The causes of this variation are still poorly understood. We hypothesized that differences in mortality in the general population contribute to differences in mortality on RRT. To evaluate this relationship, we studied general population statistics obtained from Eurostat and the individual data of 67,692 patients on RRT from 15 national and regional renal registries. These 15 registries were divided into two geographical regions: North and South Europe. Cox regression was used to assess the relative risk of death (RR) for each region with adjustment for age, gender, diabetes, and additionally general population mortality. In patients on RRT the age, gender and diabetes adjusted RR of death was 0.65 (95% CI (0.64-0.66)) for South compared to North, while in the general population the age and gender standardized RR of death was 0.91. After adjustment for general population mortality in addition to age, gender, and diabetes, the RR of death for patients on RRT in the South changed from 0.65 to 0.74 (95% CI (0.72-0.75)), which indicates that general population mortality accounted for 26% of the region-related mortality difference on RRT. In conclusion, within Europe there exist considerable international differences in the mortality of patients on RRT. Twenty-six percent of the European north-south mortality difference in RRT could be attributed to differences in general population mortality. Our data support the hypothesis that general population mortality is an important factor to take into account when making RRT mortality comparisons. [ABSTRACT FROM AUTHOR]

Epidemiological studies aim at assessing the relationship between exposures and outcomes. Clinicians are interested in knowing not only whether a link between a given exposure (e.g. smoking) and a certain outcome (e.g. myocardial infarction) is statistically significant, but also the magnitude of this relationship. The 'measures of effect' are indexes that summarize the strength of the link between exposures and outcomes and can help the clinician in taking decisions in every day clinical practice. In epidemiological studies, the effect of exposure can be measured both in relative and absolute terms. The risk ratio, the incidence rate ratio, and the odds ratio are relative measures of effect. Risk difference is an absolute measure of effect and it is calculated by subtracting the risk of the outcome in exposed individuals from that of unexposed. [ABSTRACT FROM AUTHOR]

What is this patient's prognosis regarding graft rejection? Do patients using a particular drug live longer than those not using it? How does this co-morbidity affect access to transplantation? To answer this type of questions one needs to perform survival analysis. This paper focuses on the Kaplan-Meier method, the most popular method used for survival analysis. It makes it possible to calculate the incidence rate of events like recovery of renal function, myocardial infarction or death by using information from all subjects at risk for these events. It explains how the method works, how survival probabilities are calculated, survival data can be summarized and survival in groups can be compared using the logrank test for hypothesis testing. In addition, it provides some guidance regarding the presentation of survival plots. Finally, it discusses the limitations of the Kaplan-Meier method and refers to other methods that better serve additional purposes. [ABSTRACT FROM AUTHOR]

Introduction: It is assumed that identification and correction of asymptomatic stenoses in the vascular access circuit will prevent thrombosis that would require urgent intervention to continue hemodialysis treatment. However, the evidence base for this assumption is limited. Recent international clinical practice guidelines reach different conclusions on the use of surveillance for vascular access flow dysfunction and recommend further research to inform clinical practice., Methods: The FLOW trial is a double-blind, multicenter, randomized controlled trial with a 1:1 individual participant treatment allocation ratio over two study arms. In the intervention group, only symptomatic vascular access stenoses detected by clinical monitoring are treated, whereas in the comparison group asymptomatic stenoses detected by surveillance using monthly dilution flow measurements are treated as well. Hemodialysis patients with a functional arteriovenous vascular access are enrolled. The primary outcome is the access-related intervention rate that will be analyzed using a general linear model with Poisson distribution. Secondary outcomes include patient satisfaction, access-related serious adverse events, and quality of the surveillance process. A cost effectiveness analysis and budget impact analysis will also be conducted. The study requires 828 patient-years of follow-up in 417 participants to detect a difference of 0.25 access-related interventions per year between study groups., Discussion: As one of the largest randomized controlled trials assessing the clinical impact of vascular access surveillance using a strong double-blinded study design, we believe the FLOW trial will provide much-needed evidence to improve vascular access care for hemodialysis patients., 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.

Despite the increasing implementation of formative assessment in medical education, its' effect on learning behaviour remains questionable. This effect may depend on how students value formative, and summative assessments differently. Informed by Expectancy Value Theory, we compared test preparation, feedback use, and test-taking motivation of medical students who either took a purely formative progress test (formative PT-group) or a progress test that yielded study credits (summative PT-group). In a mixed-methods study design, we triangulated quantitative questionnaire data (n = 264), logging data of an online PT feedback system (n = 618), and qualitative interview data (n = 21) to compare feedback use, and test-taking motivation between the formative PT-group (n = 316), and the summative PT-group (n = 302). Self-reported, and actual feedback consultation was higher in the summative PT-group. Test preparation, and active feedback use were relatively low and similar in both groups. Both quantitative, and qualitative results showed that the motivation to prepare and consult feedback relates to how students value the assessment. In the interview data, a link could be made with goal orientation theory, as performance-oriented students perceived the formative PT as not important due to the lack of study credits. This led to low test-taking effort, and feedback consultation after the formative PT. In contrast, learning-oriented students valued the formative PT, and used it for self-study or self-assessment to gain feedback. Our results indicate that most students are less motivated to put effort in the test, and use feedback when there are no direct consequences. A supportive assessment environment that emphasizes recognition of the value of formative testing is required to motivate students to use feedback for learning., (© 2024. The Author(s).)

Background: A low-protein diet (LPD) is recommended to patients with advanced chronic kidney disease (CKD), whereas geriatric guidelines recommend a higher amount of protein. The aim of this study was to evaluate the safety of LPD treatment in older adults with advanced CKD., Methods: The EQUAL study is a prospective, observational study including patients ≥65 years of age with an incident estimated glomerular filtration rate <20 ml/min/1.73 m2 in six European countries with follow-up through 6 years. Nutritional status was assessed by a 7-point subjective global assessment (SGA) every 3-6 months. Prescribed diet (g protein/kg of bodyweight) was recorded on every study visit; measured protein intake was available in three countries. Time to death and decline in nutritional status (SGA decrease of ≥2 points) were analysed using marginal structural models with dynamic inverse probability of treatment and censoring weights., Results: Of 1738 adults (631 prescribed LPD at any point during follow-up), there were 1319 with repeated SGA measurements, of which 267 (20%) decreased in SGA ≥2 points and 565 (32.5%) who died. There was no difference in survival or decrease in nutritional status for patients prescribed a LPD ≤0.8 g/kg ideal bodyweight {odds ratio [OR] for mortality 1.15 [95% confidence interval (CI) 0.86-1.55)] and OR for decrease in SGA 1.11 [95% CI 0.74-1.66]} in the adjusted models. In patients prescribed a LPD <0.6 g/kg ideal bodyweight, the results were similar. There was a significant interaction with LPD and older age >75 years, lower SGA and higher comorbidity burden for both mortality and nutritional status decline., Conclusions: In older adults with CKD approaching end-stage kidney disease, a traditional LPD prescribed and monitored according to routine clinical practice in Europe appears to be safe., (© The Author(s) 2024. Published by Oxford University Press on behalf of the ERA.)