Table 4.
The effect of smoking on the odds of meeting treatment response criteria (current smokers versus ex- and never-smokers combined)
| Odds ratio; 95% confidence interval | ||||
|---|---|---|---|---|
| Model 1 | Model 2 | Model 3a / 3b | Sensitivity analysis | |
| 3-month outcome | ||||
| N 1 | 4183 to 6293 | 3759 to 6284 | 1234 to 3263 | 1024 to 6035 |
| BASDAI-50 | 0.93; 0.83–1.04 | 0.83; 0.73–0.93 |
3a 0.76; 0.61–0.95 3b 0.71; 0.60–0.84 |
Lo 0.64; 0.51–0.78 Hi 0.85; 0.73–0.99 |
| ASDAS-ID | 0.81; 0.71–0.92 | 0.72; 0.62–0.84 |
3a 0.59; 0.44–0.80 3b 0.60; 0.47–0.76 |
Lo 0.55; 0.41–0.73 Hi 0.80; 0.66–0.97 |
| ASDAS-LDA | 0.79; 0.71–0.88 | 0.74; 0.65–0.85 |
3a 0.67; 0.53–0.85 3b 0.60; 0.49–0.74 |
Lo 0.56; 0.44–0.71 Hi 0.81; 0.63–1.04 |
| ASDAS-CII | 1.11; 0.98–1.26 | 0.96; 0.84–1.10 |
3a 0.91; 0.72–1.15 3b 0.81; 0.66–0.99 |
Lo 0.80; 0.63–1.01 Hi 1.05; 0.81–1.36 |
| ASDAS-MI | 1.07; 0.93–1.24 | 0.92; 0.79–1.07 |
3a 1.01; 0.77–1.32 3b 0.84; 0.67–1.06 |
Lo 0.60; 0.46–0.80 Hi 0.96; 0.72–1.29 |
| ASAS-20 | 1.02; 0.90–1.15 | 0.78; 0.68–0.90 |
3a 0.75; 0.59–0.96 3b 0.70; 0.58–0.84 |
Lo 0.47; 0.30–0.72 Hi 0.80; 0.69–0.92 |
| ASAS-40 | 1.05; 0.92–1.20 | 0.79; 0.68–0.91 |
3a 0.67; 0.51–0.88 3b 0.68; 0.55–0.83 |
Lo 0.41; 0.25–0.66 Hi 0.85; 0.66–1.10 |
| ASAS-5/6 | 1.07; 0.92–1.24 | 0.78; 0.66–0.92 |
3a 0.61; 0.44–0.83 3b 0.66; 0.52–0.83 |
Lo 0.44; 0.26–0.73 Hi 0.79; 0.65–0.96 |
| 12-month outcome | ||||
| N 1 | 4184 to 7126 | 3834 to 6886 | 932 to 4409 | 912 to 6234 |
| BASDAI-50 | 0.87; 0.79–0.96 | 0.77; 0.68–0.86 |
3a 0.69; 0.55–0.87 3b 0.66; 0.57–0.77 |
Lo 0.67; 0.55–0.81 Hi 0.82; 0.67–0.995 |
| ASDAS-ID | 0.76; 0.68–0.86 | 0.68; 0.59–0.79 |
3a 0.65; 0.48–0.88 3b 0.58; 0.48–0.70 |
Lo 0.56; 0.45–0.70 Hi 0.79; 0.58–1.08 |
| ASDAS-LDA | 0.82; 0.74–0.91 | 0.81; 0.71–0.93 |
3a 0.73; 0.56–0.94 3b 0.72; 0.60–0.86 |
Lo 0.73; 0.59–0.89 Hi 0.86; 0.74–0.998 |
| ASDAS-CII | 1.10; 0.97–1.25 | 0.95; 0.82–1.09 |
3a 0.83; 0.64–1.08 3b 0.82; 0.67–0.99 |
Lo 0.83; 0.71–0.97 Hi 1.06; 0.82–1.36 |
| ASDAS-MI | 1.08; 0.95 1.22 | 0.95; 0.82–1.10 |
3a 1.02; 0.76–1.36 3b 0.89; 0.73–1.08 |
Lo 0.82; 0.70–0.97 Hi 1.06; 0.87–1.29 |
| ASAS-20 | 1.12; 0.99–1.26 | 0.87; 0.75–1.005 |
3a 0.82; 0.62–1.08 3b 0.80; 0.67–0.96 |
Lo 0.80; 0.69–0.94 Hi 0.94; 0.73–1.21 |
| ASAS-40 | 1.10; 0.98–1.24 | 0.83; 0.72–0.95 |
3a 0.72; 0.54–0.96 3b 0.75; 0.63–0.89 |
Lo 0.65; 0.49–0.86 Hi 0.85; 0.72–0.99 |
| ASAS-5/6 | 1.08; 0.94–1.23 | 0.82; 0.69–0.96 |
3a 0.75; 0.54–1.04 3b 0.72; 0.59–0.88 |
Lo 0.72; 0.60–0.86 Hi 0.86; 0.70–1.06 |
1 N is the minimum and maximum number of participants in the subsequent models
Model 1 – Crude association, unadjusted. All models present the odds ratio associated with being a current smoker, versus ex- and never-smokers combined
Model 2 – As per Model 1 but adjusted for age, sex, country, calendar year, quintiles of disease duration and baseline disease activity
Model 3a/3b – As per Model 2 but also adjusted for other lifestyle factors, denoted superscript 3a (Model 3a, adjusted for alcohol consumption) and 3b (Model 3b, adjusted for BMI categories)
Additional information, including the number of participants in each model, and a full description of Model 2, is shown in the supplementary data
Sensitivity analysis – As per Model 2 but additionally adjusted, in turn, for all other variables shown in Table 2. Results from individual models are shown in supplementary data. Here, the lowest and highest odds ratios are presented, denoted superscript Lo and Hi, respectively