Impact of smoking on treatment adherence stratified by TNFi drug type
| Adalimumab | Infliximab | Etanercept | ||||
|---|---|---|---|---|---|---|
| HR (95% CI) | p Value | HR (95% CI) | p Value | HR (95% CI) | p Value | |
| Smoking status | ||||||
| Never | 1 | 0.22 | 1 | 0.04 | 1 | 0.01 |
| Current | 0.76 (0.49 to 1.18) | 1.56 (1.01 to 2.41) | 1.74 (1.13 to 2.68) | |||
| Gender | ||||||
| Men | 1 | 0.02 | 1 | 0.78 | 1 | 0.7 |
| Women | 1.66 (1.10 to 2.56) | 1.05 (0.69 to 1.6) | 1.10 (0.71 to 1.69) | |||
| Disease duration, years | ||||||
| 0–2 | 1 | 1 | 1 | |||
| 3–7 | 0.91 (0.55 to 1.50) | 0.72 | 1.02 (0.59 to 1.76) | 0.94 | 0.93 (0.53 to 1.61) | 0.80 |
| >8 | 0.73 (0.43 to1.22) | 0.23 | 0.71 (0.44 to 1.13) | 0.15 | 1.04 (0.71 to 1.69) | 0.88 |
| Age, years | ||||||
| ≤38 | 1 | 1 | 1 | |||
| 39–47 | 0.61 (0.32 to 1.2) | 0.15 | 1.16 (0.67 to 2.01) | 0.58 | 1.16 (0.63 to 2.11) | 0.63 |
| 48–56 | 1.18 (0.71 to 2.0) | 0.52 | 1.08 (0.58 to 2.03) | 0.78 | 1.14 (0.61 to 2.11) | 0.67 |
| ≥57 | 1.02 (0.57 to 1.82) | 0.95 | 1.05 (0.58 to 1.91) | 0.86 | 1.16 (0.59 to 2.24) | 0.66 |
| TNFi start year | ||||||
| 2000–2006 | 1 | 1 | 1 | |||
| 2007–2009 | 1.32 (0.76 to 2.28) | 0.32 | 1.61 (0.98 to 2.64) | 0.06 | 1.39 (0.83 to 2.32) | 0.19 |
| 2010–2011 | 0.76 (0.37 to 1.55) | 0.45 | 3.74 (1.83 to 7.61) | 0.01 | 1.48 (0.77 to 2.8) | 0.23 |
| Baseline swollen joint count, number per joint increase | 1.02 (0.97 to 1.07) | 0.34 | 1.04 (0.98 to 1.09) | 0.19 | Not included* | |
Multivariate Cox regression analyses including a priori confounders.
*Swollen joint count did not alter the OR of smoking by >10% and was not included in the multivariate analysis.
Baseline distribution of covariates according to TNFi drug type (adalimumab/infliximab/etanercept). Current smokers: 34%/37%/27%. Males: 50%/55%/47%. Age, median (IQR): 48 (38–56) years/48 (39–56) years/48 (39–56) years. Disease duration, median (IQR): 4 (1–9) years/4 (2–12) years/4 (1–10) years.
HR, hazard ratio; TNFi, tumour necrosis factor alpha inhibitor.