Variable/outcome | Hypothesis | Outcome measure | Method of analysis |
---|---|---|---|
1. Primary | |||
a. Proportion of patients smoking | Intervention improves smoking cessation rates from baseline to 16 weeks | Carbon monoxide in ppm in exhaled air | Chi-squared test |
b. Proportion achieving at least 50 % reduction in number of cigarettes smoked | Intervention reduces number of cigarettes smoked from baseline to 16 weeks | Self-reported daily number of cigarettes smoked | Chi-squared test |
2. Secondary | |||
Number of cigarettes smoked | Reduction in number of cigarettes | Self-reported daily number of cigarettes smoked | t-test and regression methods with secondary outcomes as dependent variable adjusted for variables defined under additional analysis |
Carbon monoxide in exhaled air | Reduced CO levels | Carbon monoxide in ppm in exhaled air | |
C-reactive protein | Reduced levels | CRP in mg/L | |
Leucocyte count | Levels within reference limit | Leucocyte count in 109/L | |
Psychological well-being | Increased score | Hopkins Symptom Checklist (SCL-10) | |
Physical fitness | Increased score | 4-min step test, number of steps | |
Quality of life | Increased score | EuroQoL EQ-5D-5L-questionaire | |
Fatigue | Less Fatigue | Fatigue Symptom Scale (FSS-3) | |
Dyspnoea | Less after intervention | Modified Medical Research Council (mMRC)-scale | |
Physical activity | Increased | Physical Activity Questionnaire (IPAQ) | |
3. Additional analysis | |||
OAT-medication | Choice of OAT-medication impacts primary outcome | Regression methods with OAT medication as categorical co-variate. | |
OAT-medication doses | Higher doses inhibits smoking cessation | Regression methods with OAT-doses as independent variable | |
Adjusted for age | Co-variates impact the outcomes of the trial | Regression methods with appropriate interaction term | |
Adjusted for sex | |||
Adjusted for i.v. drug use | |||
Adjusted for known COPD | |||
Impact of number of cigarettes smoked on secondary outcomes | Fewer cigarettes smoked results in improved secondary outcomes | Regression methods with secondary outcome as dependent variable and number of cigarettes smoked as independent variable |