Introduction: Many smokers reduce their cigarette consumption during failed attempts to quit. We report the impact of changes in consumption on smoking-related respiratory symptom severity (SRRSS).
Methods: Between February 2002 and May 2004 we recruited 383 smokers from 5 methadone maintenance programs for a randomized trial of nicotine replacement plus behavioral treatment versus nicotine replacement alone for smoking cessation. Cigarette use in the 28 days prior to the interview, and severity of SRRSS using a 7-item respiratory index, were assessed at baseline and at 3-month follow-up.
Outcome: Baseline minus 3-month assessment difference in SRRSS score.
Results: Follow-up of 319 participants (83.3%), mean age 40.4 years, 51.4% male, who smoked 26.4 cigarettes per day, demonstrated a mean reduction of 16.7 cigarettes per day. A reduction in cigarette use was positively and significantly (b=0.29, t=5.16, P<.001) associated with a reduction in smoking-related symptom severity after adjusting for age, gender, race, years of regular smoking, baseline nicotine dependence, and history of treatment for asthma or emphysema. A 1 standard deviation reduction in average daily smoking (about 14.1 cigarettes) was associated with a 0.28 standard deviation decrease in smoking-related symptom severity.
Conclusion: Reduction in symptom severity increases as absolute reduction in daily smoking increases. This is the first study to demonstrate an association between subjective short-term health changes and reduction in smoking.