Logistic regression of work disability employment status in SLE to obtain p values after dropping insignificant variables using STEPWISE elimination
| β coefficient | p Value (multivariate) | OR | OR 95% CI | ||
|---|---|---|---|---|---|
| Intercept | 1.2 | ||||
| Age | 0.03 | 0.005 | 1.031 | 1.012 | 1.055 |
| Disease duration | |||||
| SLICC/DI, score >1 | 0.21* | 0.014 | 1.232 | 1.042 | 1.4 |
| Pain score | |||||
| FACIT-Fatigue Score | −0.05 | <0.001 | 0.955 | 0.933 | 0.974 |
| CES-D Score (>10) | |||||
| BCSI (≤25, 100=best function) | 0.02* | 0.017 | 1.015 | 1.003 | 1.029 |
| Non-African– | |||||
| American race | −0.81 | 0.003 | 0.446 | 0.266 | 0.748 |
| Education | −0.67 | <0.001 | 0.513 | 0.390 | 0.638 |
ORs shown from final stepwise logistic regression model, after eliminating insignificant variables from the model. Controlled for slight multicollinearity by using ridge regression. Ridge coefficient=0.012, indicative of minimal effect on coefficients.
*SLICC, CES-D and BCSI were entered into the model as actual scoring variables and not 1/0 categories. N=254.
BCSI, Brief Cognitive Symptoms Index; CES-D, Center for Epidemiologic Studies Depression Scale Short Form; FACIT, Functional Assessment of Chronic Illness Therapy; SLE, systemic lupus erythematous; SLICC/DI, Systemic Lupus International Collaborative Clinics/American College of Rheumatology Damage Index.