Table 4

Age and multivariate-adjusted RR for the association between smoking and the risk of PsA among participants with psoriasis

CasesPerson-yearsAge-adjusted RR (95% CI)Multivariate-adjusted RR* (95% CI)
Reference: never smokers7623561.001.00
Smoking status
Past smokers4611911.17 (0.77 to 1.78)1.39 (0.89 to 2.16)
Current smokers358051.56 (0.98 to 2.47)1.62 (1.00 to 2.63)
 1–14 cigarettes/day123281.12 (0.55 to 2.29)1.22 (0.58 to 2.56)
 ≥15 cigarettes/day234771.91 (1.11 to 3.27)1.93 (1.09 to 3.40)
 p for trend0.0040.006
Duration, years
 <255516801.18 (0.81 to 1.74)1.35 (0.90 to 2.04)
 ≥25263161.85 (1.08 to 3.17)1.90 (1.09 to 3.33)
 p for trend0.0240.012
Pack-years
 <204414531.08 (0.71 to 1.63)1.22 (0.79 to 1.89)
 ≥20375431.87 (1.17 to 3.01)2.02 (1.24 to 3.29)
 p for trend0.0840.082
  • Adjusted for age (continuous variable), body mass index (<18.5, 18.5–24.9, 259–29.9, 30–34.9 or ≥35 kg/m2), alcohol drinking (no, <4.9, 5.0–9.9, 10–14.9, 15–29.9 or ≥30.0 g/day), vigorous physical activity (metabolic equivalent h/week, in quintiles).

  • PsA, psoriatic arthritis.