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A common problem with self-report quality-of-life questionnaires is missing data. Despite enormous care and effort to prevent it, some level of missing data is common and unavoidable. Missing data can have a detrimental impact on the data analysis. In this paper, a novel approach to imputing missing data in quality-of-life questionnaires is proposed, based on matrix and tensor decompositions. In order to illustrate and assess those methods, two datasets are considered: The first dataset contains the responses of 100 patients to a systemic lupus erythematosus-specific quality-of-life questionnaire; the other contains the responses of 43 patients to a rhino-conjunctivitis quality-of-life questionnaire. The two datasets contain almost no missing data, and for testing purposes, data entries are removed at random to have missing completely at random data. Several proportions of missing values are considered, and for each, the imputation error is assessed through k-fold cross validation. We also evaluate different imputation methods for missing at random and missing not at randomdata. The numerical results demonstrate that the proposed tensor factorization-based methods outperform standard methods in terms of root mean square error with at least 4% improvement, while the bias and variance are similar.

To investigate the association between helplessness, disability, and disease activity with health-related quality of life (HRQoL) in a multiethnic cohort of rheumatoid arthritis (RA) patients in Singapore. This cross-sectional study was conducted at Tan Tock Seng Hospital, Department of Rheumatology, Allergy and Immunology, from October 2010 to October 2011. All patients fulfilled the American College of Rheumatology 1987 criteria for RA. Socio-demographics, clinical, and patient-reported outcome (PRO) variables were collected. HRQoL outcomes were Short Form 36 (SF-36) physical and mental component summary (PCS and MCS) scores and Short Form 6 Dimensions (SF-6D) utilities. Stepwise multiple linear regression analyses were performed using HRQoL outcomes as dependent variables in separate models and with adjustment for helplessness (Rheumatology Attitudes Index, RAI), disability (Health Assessment Questionnaire, HAQ), and disease activity (Disease Activity in 28 joints) followed by socio-demographic, clinical, and PRO variables. Complete data were provided by 473 consenting subjects [mean (SD) age: 60.02 (11.04) years, 85 % female, 77 % Chinese]. After adjustment for all measured covariates, only RAI and HAQ scores remained significantly associated with SF-36 MCS (β: -0.9, p < 0.001; β: -7.0, p < 0.001) and SF-6D utilities (β: -0.005, p < 0.001; β: -0.081, p < 0.001), respectively, while only HAQ scores were significantly associated with SF-36 PCS (β: -7.7, p < 0.001). Interventions to address the sense of helplessness and to prevent or reduce disability could improve HRQoL of RA patients.

Objective: We have previously validated the English version of the Systemic Lupus Erythematosus Quality of Life Questionnaire (SLEQOL) in our patients with lupus. Many of our Chinese patients are not fluent in English and therefore a Chinese version (SLEQOL-C) has been adapted for their use., Methods: Two independent translators translated the SLEQOL into Chinese. A consensus version was derived from both sets of translations. Back translation of this version was performed by another 2 independent translators who had neither been involved in the forward translation nor encountered the SLEQOL. The final version, SLEQOL-C, was finalized after rectifying the discrepancies revealed by the back translation. Linguistic validity was tested in open interviews with bilingual patients with lupus. The SLEQOL-C and SLEQOL were administered to patients to determine whether they displayed differential item functioning (DIF)., Results: In general, most of the items in English could be expressed in Chinese precisely, although a few instructions had to be altered slightly to make them more idiomatic. The forward and back translations of the SLEQOL were accomplished without major difficulties. A total of 638 patients were interviewed (62.8% with the SLEQOL and 37.2% with the SLEQOL-C). Using DIF analysis, there was no detectable test bias due to language use after controlling for repeated observations, age, sex, and ethnicity., Conclusion: The SLEQOL-C has semantic, idiomatic, and conceptual equivalence to the SLEQOL. The rigorous process of cross-cultural translation provides some measure of quality in the content validity.

Purpose: In this real‐world observational study, we analyzed the effects of different drugs on the quality of life (QoL) of patients with systemic lupus erythematosus (SLE). Method: We identified patients in our prospective SLE Registry who received new medications. We measure QoL with MOS 36‐Item Short‐Form Health Survey (SF‐36), a generic health questionnaire, and SLEQOL, a disease‐specific instrument. We compared the patients' scores before and after initiation of treatment. Results: We identified 259 episodes of drug initiation in 193 SLE patients. SLEQOL registered statistically significant changes with intravenous cyclophosphamide (total score and the domains of physical functioning, activities, and self‐image), mycophenolate (total score, treatment, mood, and self‐image) and azathioprine (total score, activities, and mood), but not with cyclosporin A and hydroxychloroquine. Two SF‐36 subscales (general health and physical functioning) showed statistically significant improvement in the patients who received intravenous cyclophosphamide. Both instruments have floor effect. There was weak correlation between changes in the QoL instruments and the patient assessment of disease activity or an objective disease activity index. Conclusion: SLEQOL distinguishes the differential effects on QoL of the various drugs. Treatment with intravenous cyclophosphamide and mycophenolate impacted the highest numbers of domains of SLEQOL, followed by azathioprine, cyclosporin A, and hydroxychloroquine. SLEQOL may be a useful outcome measure in SLE clinical trials. [ABSTRACT FROM AUTHOR]

Objectives We evaluated the impact of type 2 diabetes mellitus (T2DM) on RA treatment and outcomes in a longitudinal RA cohort. Methods We analysed data collected in the period 2001–2013 involving 583 RA patients, including demographics, diabetes diagnosis, clinical features, treatment, ACR functional class, HAQ, and quality-of-life measurement using the Short‐Form 36. Results Seventy-seven (13.2%) of the RA patients had T2DM. DAS28 was not different in patients with T2DM at 5 years post-RA diagnosis. Fewer T2DM patients received MTX than those without T2DM (51% vs 80%, P < 0.001). Using univariate analysis, T2DM patients were more likely to experience poorer outcomes in terms of ACR functional status (P = 0.009), joint surgery (P = 0.007), knee arthroplasty (P < 0.001) and hospital admissions (P = 0.006). Multivariate regression analyses showed more knee arthroplasty (P = 0.047) in patients with T2DM. Conclusion Fewer patients with T2DM received MTX compared with those without T2DM. Patients with RA and T2DM were at higher risk of knee arthroplasty than RA patients without T2DM. [ABSTRACT FROM AUTHOR]

Objective To describe the demographic characteristics, clinical features, functional status and quality of life of elderly-onset ( EORA) and young-onset ( YORA) rheumatoid arthritis ( RA) patients in an Asian cohort. Methods We studied all RA patients in our prospective disease registry, utilizing baseline data. EORA was defined as disease onset at 60 years or older. We collected data from January 2001 to December 2012. Results There were 1206 patients in our cohort, of which 178 (14.8%) had EORA, with a mean age of onset of 66.7 ± 5.6 years. There were more males in the EORA than YORA group (23.0% vs. 14.7%, P = 0.005). EORA patients were diagnosed sooner after symptom onset and had a higher number of comorbidities (median 2 [inter-quartile range 1-3] vs. 1 (0-2), P < 0.001). They were less likely to be rheumatoid factor positive, had higher erythrocyte sedimentation rate values and lower hemoglobin concentrations. There was no significant difference in joint counts, Disease Activity Score of 28 joints activity score and prevalence of radiographic erosions. Though EORA patients had worse Health Assessment Questionnaire scores and poorer functional status than YORA ones, they had lower pain scores and higher scores in the general health and mental component summary of the Short Form-36. EORA patients received significantly lower numbers of disease-modifying anti-rheumatic drugs. Conclusions EORA and YORA patients had different demographic characteristics. Although they had similar disease activities, EORA patients received less intensive treatment. EORA patients had a higher number of RA-related co-morbidities and poorer physical functioning but they coped better emotionally and mentally. [ABSTRACT FROM AUTHOR]