Adequacy of nicotine replacement and success quitting tobacco in clinical populations: An observational study.

Abstract

Nicotine replacement therapy (NRT) for smoking cessation is an effective intervention that reduces urges to smoke by substituting a safer source of nicotine. NRT dosing is imprecise, however, and there is some evidence that patients and providers are reluctant to use the larger doses that may be appropriate for some people who smoke. In this analysis, we assess the relationship between cigarettes smoked and NRT prescribed, and between adequacy of nicotine replacement and cessation success. We analyzed data from 84,667 patients and 492 clinics participating in a province-wide NRT-based smoking cessation program. We evaluated the association between cigarettes per day (CPD) and NRT dose using descriptive methods, and used mixed-effects logistic regression to identify associations between dose and outcome. We used fractional polynomials to fit non-linear associations and multiple imputation to address missing data. Prescribed NRT doses increased much less than proportionately with CPD, with a median for higher CPD levels of about 1 mg/CPD at baseline. Doses did not increase at subsequent visits for people who continued to smoke daily. Dose-response curves derived from our model showed that initial doses below about 2 mg/CPD/day were associated with poorer outcomes. Under-dosing of NRT, both at treatment initiation and subsequent clinical contacts, is likely to contribute to the poorer treatment outcomes seen among people who smoke heavily. Improved communication with providers and patients is probably needed to overcome reluctance to use larger doses.