The possibility that tobacco use affects health-related quality of life (HRQoL) has attracted interest. However, a lack of prospective evidence weakens the case for a causal relationship. The aim was to examine the longitudinal relationship between change in smoking status and change in HRQoL in young adults.
We conducted a population-based cohort study with data collected in 2004–2006 (aged 26–36) and 2009–2011 (aged 31–41). Exposure was change in self-reported smoking status during follow-up. Outcomes were changes in physical and mental HRQoL measured by SF-12.
For physical HRQoL (n = 2080), quitters had a 2.12 (95 % confidence interval (CI) 0.73, 3.51) point improvement than continuing smokers, whereas former smokers who resumed smoking had a 2.08 (95 % CI 0.21, 3.94) point reduction than those who maintained cessation. Resumed smokers were 39 % (95 % CI 10, 75 %) more likely to have a clinically significant (>5 point) reduction of physical HRQoL than former smokers who maintained cessation. In contrast, quitters were 43 % (95 % CI 3, 98 %) more likely to have a clinically significant (>5 point) improvement in physical HRQoL than continuing smokers. Change in smoking status was not significantly associated with change in mental HRQoL (n = 1788).
Smoking by young adults was cross-sectionally associated with lower physical HRQoL and longitudinally associated with reductions in physical HRQoL. The expectation of short- to medium-term gains in physical HRQoL as well as long-term health benefits may help motivate young adult smokers to quit.