Aim: To assess the efficacy of nicotine replacement therapies (NRT) when their daily dose was adapted according to saliva cotinine concentrations.
Design: Randomized, multicentre, single-blind, controlled trial.
Setting: 21 smoking cessation clinics in France.
Participants: 310 smokers with medical comorbidities, motivated to quit, smoking ≥ 10 cigarettes/day, for whom smoking cessation was mandatory.
Interventions: NRT were administered for 3 months. The Standard Care group (SCG) received nicotine patches with monthly dose decreases; buccal absorption NRT could be coadministered at the discretion of the investigator. In the Dose Adaptation group (DAG), the aim was a 100 ± 5 % nicotine substitution with respect to the smoking state based on the determination of saliva cotinine concentrations. NRT daily doses were prescribed according to the previous week’s saliva cotinine concentrations in the DAG; saliva cotinine concentrations were not provided in the SCG.
Measurements: Prolonged abstinence rate (week 9-12, main outcome measure), point prevalence and continuous abstinence rate, saliva cotinine concentration, NRT daily dose, craving for cigarettes.
Findings: The median daily prescribed NRT dose was 30 and 31 mg/day on the first study week and 17.25 and 35.5 mg/day during weeks 9 to 12 in the SCG and DAG, respectively. Saliva cotinine remained stable in the DAG and decreased in the SCG (p < 0.01) by weeks 9 to 12. The cotinine substitution rate was significantly lower in the SCG than in the DAG.
Despite differences in NRT doses and cotinine substitution rates, prolonged (SCG: 26.4 %, DAG: 30.3 %), continuous (SCG: 8 %, DAG: 12 %), and point prevalence abstinence rates were similar.
Conclusion: In smokers with medical comorbidities and highly motivated to quit, the adaptation of the NRT daily dose according to saliva cotinine does not appear to be substantially superior to standard NRT use.