Rheumatoid Arthritis: Lavalley M

Zhang B, Lavalley M, Felson DT. · Clinical Epidemiology Unit, Boston University, 715 Albany Street, A203 Boston, MA 02118, USA. · Ann Rheum Dis. · Pubmed #18697778 No free full text.

Abstract: OBJECTIVE: To test whether rheumatoid arthritis (RA) trials treatment efficacy versus control is better detected for patients with lower tender joint counts (TJC) or swollen joint counts (SJC) than for higher counts. METHODS: Using data from six large multicentre trials (N = 2002) and an intent-to-treat approach at 6 months, two subtrials were created within each trial, the lower disease activity group (defined by TJC less than overall median) and the higher disease activity group. The same approach was used for SJC. Active treatment was tested for treatment control differences using several RA trial outcome measures: ACR20, EULAR response, ACRHybrid. Sample sizes needed for higher TJC and SJC RA trials versus lower TJC and SJC trials were compared. RESULTS: Subtrials of subjects with lower TJC were found to have much higher sensitivity to change than those of subjects with higher TJC across all trials and outcome measures. A trial with lower TJC patients would require a smaller sample size than those with higher TJC patients. Results were not consistent for SJC subgroups. Three reasons were found for sensitivity to change of lower TJC: compared with higher TJC, those with lower TJC showed greater response to active treatment. SUBJECTS: with higher TJC on control treatment had greater percentage improvement and more variable responses than those in the lower TJC group. CONCLUSIONS: In RA trials, patients with lower disease activity within the range of current trial eligibility are more likely to show treatment efficacy than patients with higher disease activity. Lowering thresholds especially for TJC in trials may make it easier to detect treatment effects in RA.

Allaire S, Wolfe F, Niu J, Lavalley M, Michaud K. · Boston University, Boston, Massachusetts, USA. · Arthritis Rheum. · Pubmed #16082625 links to  free full text

Abstract: OBJECTIVE: To examine the extent and financial impact of work disability among older workers with rheumatoid arthritis (RA). METHODS: Year 2002 data from 5,419 subjects with RA < 65 years of age in the National Data Bank for Rheumatic Diseases were used, along with US population data. Measures of work disability were employment status, part-time work, sick day use, and limitation in work demands; the latter was assessed by the Work Limitations Questionnaire (WLQ). Measures of financial status were median household income and poverty level income. Statistical procedures included logistic and linear regression, Wilcoxon's rank sum test, and chi-square test. RESULTS: Despite being better educated, subjects with RA ages 55-64 years had lower employment rates than individuals of the same age in the US (women 40% versus 53% and men 54% versus 66%). These older subjects with RA had stopped working more often than younger subjects with RA, and more worked part time (40% versus 34%; P < 0.01). However, the older subjects used sick time less often than younger subjects (35% versus 41%; P < 0.01) and were similarly limited in job demands, e.g., physical demands (mean WLQ subscale score 27.0 versus 26.6; P = 0.65). Median household income of older employed subjects was 20,000 dollars greater than that of retired subjects; 56% of retired subjects had incomes lower than US median income versus 32% of employed subjects, and 11% had income below the poverty level. CONCLUSION: Premature work cessation in persons with RA ages 55-64 years is a serious problem that needs to be addressed.