Performance of the Dutch SF-36 version 2 as a measure of health-related quality of life in patients with rheumatoid arthritis.

BACKGROUND: The aim of this study was to examine the measurement properties of the Dutch SF-36 version 2 (SF-36v2) health survey in patients with rheumatoid arthritis (RA). METHODS: Scaling assumptions, internal reliability, and internal construct validity were examined using available data from 1884 RA patients included in the Dutch Rheumatoid Arthritis Monitoring (DREAM) registry. External construct validity and responsiveness to change were examined using baseline and 6-month follow-up data from a subset of 387 early RA patients participating in the DREAM remission induction cohort. RESULTS: The individual items of the SF-36v2 adequately met scaling assumptions, although four items correlated too highly with items from different scales. Internal consistency was high for all eight scales and the physical and mental health components underlying the scales were replicated, supporting the use of the standard scoring algorithms. The SF-36v2 scales demonstrated minimal floor effects and ceiling effects were noteworthy only for the role-physical, social functioning, and role-emotional scales. Correlations with other core measures were as expected and the SF-36v2 showed excellent known-groups validity in distinguishing between patients with low or moderate-high disease activity. All scales related to physical health showed moderate to large responsiveness to change in patients that achieved low disease activity at six months. CONCLUSION: The SF-36v2 appears to be a psychometrically sound tool for the assessment of health-related quality of life of Dutch patients with RA.

Predictors for the 5-year risk of serious infections in patients with rheumatoid arthritis treated with anti-tumour necrosis factor therapy: a cohort study in the Dutch Rheumatoid Arthritis Monitoring (DREAM) registry.

OBJECTIVE: The use of TNF inhibitors leads to an increased risk of serious infections in RA. Predicting this risk would facilitate the prevention of serious infections. The objective of this study was to identify which factors are predictive of the increased risk of serious infections in RA patients treated with TNF inhibiting therapy. METHODS: Data from the Dutch Rheumatoid Arthritis Monitoring (DREAM) registry of 2044 patients with RA were used for the analyses. Data were censored at stopping TNF inhibitors or end of observation time up to 5 years. Univariate and multivariate analysis of baseline variables was performed using Cox regression with time to the first serious infection as dependent variable. RESULTS: During a follow-up time of 5 years, 128 of 2044 (6.3%) patients developed a first serious infection with a total of 141 serious infections. The incidence rate in the first year after start of TNF inhibiting therapy was 4.57 first serious infections per 100 patient-years and 2.91 per 100 patient-years over 5 years. Age, corticosteroid use, visual analogue scale (VAS) pain, HAQ, tender joint count 28 joints (TJC28) and the presence of comorbidities were significant predictors for developing a serious infection during TNF inhibiting therapy in the multivariate model. CONCLUSION: Age, corticosteroid use, VAS pain, HAQ, TJC28 and the presence of comorbidities all at baseline were significant predictors for developing a serious infection during TNF inhibiting therapy in RA patients.

Genome-wide association analysis of anti-TNF drug response in patients with rheumatoid arthritis.

BACKGROUND: Treatment strategies blocking tumour necrosis factor (anti-TNF) have proven very successful in patients with rheumatoid arthritis (RA). However, a significant subset of patients does not respond for unknown reasons. Currently, there are no means of identifying these patients before treatment. This study was aimed at identifying genetic factors predicting anti-TNF treatment outcome in patients with RA using a genome-wide association approach. METHODS: We conducted a multistage, genome-wide association study with a primary analysis of 2 557 253 single-nucleotide polymorphisms (SNPs) in 882 patients with RA receiving anti-TNF therapy included through the Dutch Rheumatoid Arthritis Monitoring (DREAM) registry and the database of Apotheekzorg. Linear regression analysis of changes in the Disease Activity Score in 28 joints after 14 weeks of treatment was performed using an additive model. Markers with p<10(-3) were selected for replication in 1821 patients from three independent cohorts. Pathway analysis including all SNPs with p<10(-3) was performed using Ingenuity. RESULTS: 772 markers showed evidence of association with treatment outcome in the initial stage. Eight genetic loci showed improved p value in the overall meta-analysis compared with the first stage, three of which (rs1568885, rs1813443 and rs4411591) showed directional consistency over all four cohorts studied. We were unable to replicate markers previously reported to be associated with anti-TNF outcome. Network analysis indicated strong involvement of biological processes underlying inflammatory response and cell morphology. CONCLUSIONS: Using a multistage strategy, we have identified eight genetic loci associated with response to anti-TNF treatment. Further studies are required to validate these findings in additional patient collections.

Incremental cost-effectiveness of cyclooxygenase 2-selective versus nonselective nonsteroidal anti-inflammatory drugs in a cohort of coumarin users: a pharmacoeconomic analysis linked to a case-control study.

BACKGROUND: A previous case-control study involving concomitant users of coumarin and nonsteroidal anti-inflammatory drugs (NSAIDs) found that cyclooxygenase 2 (COX-2)-selective NSAIDs were associated with fewer bleeding complications than nonselective NSAIDs. OBJECTIVE: The goal of this study was to determine the incremental cost-effectiveness of COX-2-selective versus nonselective NSAIDs in relation to the occurrence of bleeding complications in a cohort of concomitant coumarin users. METHODS: The pharmacoeconomic evaluation was linked to a case-control analysis (patients with and without bleeding complications) based on data from the earlier study in users of concomitant coumarin and NSAIDs. Medical costs associated with NSAID use and bleeding complications were estimated according to Dutch guidelines for pharmacoeconomic analyses, based on Dutch drug prices and national averages for health care costs. Rofecoxib, meloxicam, and nabumetone were considered COX-2 selective. Total costs were calculated and compared for 2 hypothetical scenarios in which patients used either COX-2-selective or nonselective NSAIDs. Sensitivity analyses were performed in which both the odds ratios (ORs) and the costs of NSAIDs and bleeding episodes were varied. RESULTS: A total of 1,491 bleeding complications occurred in 4400 coumarin users: among the 221 (15%) NSAID users with a bleeding episode, 96% used a nonselective NSAID and 4% used a COX-2-selective NSAID. The adjusted OR of a bleeding episode for nonselective compared with COX-2-selective NSAIDs was 3.07 (95% CI, 1.18-8.03). The estimated mean cost of a bleeding episode was 478 per patient. Factoring in the excess cost of a COX-2-selective NSAID compared with a nonselective NSAID, as well as the cost savings in averted bleeding episodes, it was determined that there would be net medical cost savings of 53,800 and 162 averted bleeding episodes if the entire patient group received COX-2-selective NSAIDs rather than nonselective NSAIDs. The sensitivity analysis showed these results to be robust. CONCLUSION: In this study population of concomitant coumarin and NSAID users, the reduction in bleeding complications with the use of more expensive COX-2-selective inhibitors was associated with net medical cost savings compared with nonselective NSAIDs.

Concomitant coumarin-NSAID therapy and risk for bleeding.

OBJECTIVE: To investigate the risk of bleeding complications during the combined use of coumarin derivatives and nonsteroidal antiinflammatory drugs (NSAIDs) compared with the use of coumarin derivatives alone. SUBJECTS AND METHODS: In this 1-year observational study, the local outpatient anticoagulation office detected all coumarin users with bleeding complications. These patients were sent questionnaires regarding the type and consequences of the bleeding as well as previous NSAID use. The local pharmacists detected patients with concomitant coumarin and NSAID prescriptions (but no bleeding). The relative risk for bleeding due to concomitant coumarin and NSAID use was estimated. RESULTS: During 1 year, 738 hemorrhages were identified in 681 coumarin users. In 12.2% of these cases, an NSAID was involved. In contrast, in the whole population of coumarin users, 2.5% were prescribed an NSAID. Therefore, the relative risk of NSAID use with regard to bleeding complications was 5.8 (95% CI 2.3 to 13.6). CONCLUSIONS: NSAID use during coumarin therapy considerably increases the bleeding risk compared with coumarin therapy alone. Although in daily practice these medications are frequently prescribed concomitantly, our results underscore the contraindication of concomitant use of NSAIDs and coumarin derivatives.