Dynamics of smoking cessation and health-related quality of life among Canadians.

BACKGROUND

People who smoke are at increased risk of lung and other cancers, heart attack, stroke, chronic lung disease and premature death. After smoking cessation, these risks diminish, but little is known about the time required to regain the level of health of people who have never smoked. This analysis describes trajectories of health-related quality of life (HRQL) in relation to smoking status, focusing on the time required for former smokers to achieve an HRQL level similar to that of never-smokers.

METHODS

Data were from nine cycles (1994/1995 through 2010/2011) of the National Population Health Survey. Analyses were based on longitudinal data for 3,341 men and 4,143 women aged 40 or older in 1994/1995. Multi-level growth modelling was used to describe HRQL trajectories over the 16-year follow-up period in relation to smoking status, which was updated every two years.

RESULTS

Across all ages and for both sexes, persistent smokers had lower HRQL than did never-smokers. Among men, HRQL improved after 5 years of quitting; after 20 years, HRQL was similar to that of never-smokers. Among women, after 10 years of cessation, the HRQL of former smokers was clinically similar to that of those who had never smoked.

INTERPRETATION

At any age, and for both men and women, long-term smoking cessation results in improvements in HRQL.