How stable are stop smoking practitioner success rates over time?

Stop smoking practitioners appear to differ in effectiveness, but the stability of their success rates over time is unknown. The purpose of this study was to assess the degree of stability of success rates of stop smoking practitioners over several years of practice. Using routinely collected practice data, the success rates of 197 practitioners active between April 2009 and April 2012 in the English stop smoking services were correlated across years before and after adjusting for client and intervention characteristics. Changes in client and intervention characteristics were assessed. Success rates for individual practitioners correlated highly in successive years (r = 0.64 to 0.68, p < 0.001, ICC = 0.56) and moderately over non-successive years (r = 0.39 to 0.51, p < 0.001). There was no evidence for increasing effectiveness over time. Practitioners' effectiveness is moderately stable over time. Research is needed to establish what characterises the practice of the more successful practitioners.