Variables | Smokers Estimate | Nonsmokers Estimate | Mean Difference (95% CI), p |
---|---|---|---|
CDAI | 14.77 | 12.66 | 2.11 (−1.26 to 5.47), p = 0.22 |
PtGA | 4.82 | 4.19 | 0.64 (0.16–1.12), p = 0.01 |
PGA | 2.43 | 2.23 | 0.20 (−0.61 to 1.01), p = 0.63 |
Swollen joints | 5.91 | 3.33 | 2.58 (1.28–3.89), p < 0.001 |
Tender joints | 1.53 | 2.62 | −1.09 (−2.16 to −0.02), p = 0.05 |
CRP, mg/l | 13.22 | 12.26 | 0.96 (−2.74 to 4.66), p = 0.61 |
The estimated causal effect of smoking on disease activity at 27 months was 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; RF: rheumatoid factor; DMARD: disease-modifying antirheumatic drugs; anti-CCP: anticyclic citrullinated peptide.