Generalized estimating equation results demonstrating the expected difference in disease activity measures comparing smokers to nonsmokers over the study period.
| Variables | β (95% CI), p |
|---|---|
| CDAI | 0.36 (−1.51 to 2.24), p = 0.71 |
| PtGA | 4.62 (−1.02 to 10.26), p = 0.11 |
| PGA | −0.09 (−4.41 to 4.23), p = 0.97 |
| Swollen joint count | 0.08 (−0.73 to 0.90), p = 0.84 |
| Tender joint count | 0.42 (−0.35 to 1.18), p = 0.29 |
| CRP, mg/l | −1.64 (−5.30 to 2.02), p = 0.38 |
An expected difference in disease activity for a unit change in the predictor (i.e., comparing smokers to nonsmokers) over the population, adjusted for baseline covariates (sex, age, race/ethnicity, past smoking, disease activity, obesity, RF status, anti-CCP status) and time-varying covariates (biologic/small molecule DMARD, synthetic DMARD, whether the outcome value was imputed, and missed visit status). CDAI: Clinical Disease Activity Index; PtGA: patient’s global assessment; PGA: physician’s global assessment; CRP: C-reactive protein; DMARD: disease-modifying antirheumatic drugs; RF: rheumatoid factor; anti-CCP: anticyclic citrullinated peptide.