NAge-adjusted and gender-adjusted, mean difference (95% CI)Adjusted for baseline variables*, mean difference (95% CI)Adjusted for baseline variables* and time-varing smoking, mean difference (95% CI)Adjusted for baseline variables* and time-varying treatment/smoking, mean difference (95% CI)
HAQ scores†
 Patients with IP16510.09 (0.03 to 0.16)0.05 (−0.00 to 0.10)0.05 (−0.00 to 0.10)0.01 (−0.05 to 0.06)
 Patients with RA9600.08 (−0.01 to 0.17)0.01 (−0.06 to 0.08)0.01 (−0.06 to 0.08)−0.05 (−0.12 to 0.02)

  • Cohort 1 is the reference category for all models.

  • *Baseline variables controlled for age, gender, time from onset to baseline, rheumatoid factor, anticyclic citrullinated protein antibodies, smoking status, HAQ, swollen/tender joint counts (51), C reactive protein, taking sDMARDs and Disease Activity Score 28.

  • †Mortality risk modelled using Cox proportional hazards model, cancer/CVD/respiratory disease modelled using competing risks regression, swollen and tender joint counts modelled using population-average negative binomial regression, and HAQ score modelled using generalised estimating equations analysis.

  • CVD, cardiovascular disease; HAQ, Health Assessment Questionnaire; IP, inflammatory polyarthritis; RA, rheumatoid arthritis; sDMARD, synthetic disease-modifying antirheumatic drug; SHR, subhazard ratio.