Table 2.
Outcomes and effect sizes of interventions to support smoking cessation
| Type of outcome | Study | More intensive intervention | Less intensive intervention | Comparison | Effect |
|---|---|---|---|---|---|
| Objective measures | |||||
| Biochemically verified smoking cessation | Ardron et al19 | 0 | 1 (3%) | – | – |
| Canga et al*20 | 25 (17%) | 3 (2%) | Incidence ratio (95% CI) | 7.5 (2.3 to 24.4) | |
| Hokanson et al*23 | 4 (7%) | 2 (4%) | χ2 test for difference in abstinence rate | p=0.077 | |
| Sawicki et al18 | 2 (5%) | 7 (16%) | Difference in point prevalence of cessation | Reported as not significant | |
| Urinary cotinine–creatinine ratio, µg/mg | Ardron et al19 | 7.6 (4.5) | 6.7 (4.4) | – | – |
| Breath CO (µL/L) | Ardron et al19 | 18.2 (10.0) | 19.4 (8.9) | – | – |
| HbA1c <7% (53 mmol/mol) | Hokanson et al23 | 35 (61%) | 43 (75%) | Difference in proportion of patients achieving HbA1c <7% | Reported as not significant |
| Self-reported measures | |||||
| 7-day abstinence | Ng et al*22 | 14 (37%) | 10 (30%) | Allocation effect in logistic regression model | Reported as not significant |
| Thankappan et al*21 | 58 (52%) | 14 (13%) | Adjusted OR (95% CI) | 8.4 (4.1 to 17.1) | |
| Number of cigarettes smoked daily | Canga et al20 | 15.5† | 18.1† | Difference in change in mean cigarettes per day from baseline (95% CI) | −3.0 (−1.1 to −4.9) |
| >50% reduction in number of cigarettes smoked daily | Thankappan et al21 | 20 (18%) | 25 (22%) | Adjusted OR (95% CI) | 1.9 (0.8 to 4.1) |
| Attempts to quit or reduce smoking | Ng et al22 | 21 (55%) | 16 (48%) | Allocation effect in logistic regression model | Reported as not significant |
| Incidence of smoking relapse | Canga et al20 | 49 (33%) | 14 (11%) | Difference (95% CI) in incidence of relapse | 22.8% (13.6 to 32.0) |
Data presented as number of events (%) or mean (SD).
*Reported as a primary outcome.
†SDs not reported.
CO, carbon monoxide; HbA1c, glycated haemoglobin.