Effectiveness of a motivational intervention based on spirometry results to achieve smoking cessation in primary healthcare patients: randomised, parallel, controlled multicentre study

OBJECTIVE: This 12-month study in a primary healthcare network aimed to assess the effectiveness of usual smoking cessation advice compared with personalised information about the spirometry results. DESIGN: Randomised, parallel, controlled, multicentre clinical trial. SETTING: This study involved 12 primary healthcare centres (Tarragona, Spain). PARTICIPANTS: Active smokers aged 35–70 years, without known respiratory disease. Each participant received brief smoking cessation advice along with a spirometry assessment. Participants with normal results were randomised to the intervention group (IG), including detailed spirometry information at baseline and 6-month follow-up or control group (CG), which was simply informed that their spirometry values were within normal parameters. MAIN OUTCOME: Prolonged abstinence (12 months) validated by expired-CO testing. RESULTS: Spirometry was normal in 571 patients in 571 patients (45.9% male), 286 allocated to IG and 285 to CG. Baseline characteristics were comparable between the groups. Mean age was 49.8 (SD ±7.78) years and mean cumulative smoking exposure was 29.2 (±18.7) pack-years. Prolonged abstinence was 5.6% (16/286) in the IG, compared with 2.1% (6/285) in the CG (p=0.03); the cumulative abstinence curve was favourable in the IG (HR 1.98; 95% CI 1.29 to 3.04). CONCLUSIONS: In active smokers without known respiratory disease, brief advice plus detailed spirometry information doubled prolonged abstinence rates, compared with brief advice alone, in 12-month follow-up, suggesting a more effective intervention to achieve smoking cessation in primary healthcare. TRIAL REGISTRATION NUMBER: NCT01194596.