The effect of smoking cessation on respiratory health in young adults

Background: Smoking cessation is well established in public health as well as a clinical work to effectively reduce respiratory disease burden. However, data from population-based cohort studies on respiratory health benefit in young adults are still limited. Methods: We report data from the Study of Occupational Allergy Risks (SOLAR) conducted in Dresden and Munich (Germany). The study population of 919 smokers was first studied in 1995/96at age 9–11 years with a parental questionnaire and a clinical examination. At the follow-up in 2002/03 and 2007/08 the young adults completed questionnaires on respiratory health, living and exposure conditions. At the second follow-up they again underwent a clinical examination. We calculated relative risks (RR) with 95% confidence intervals (95% CI) and adjusted for confounders using a modified poisson regression approach. Results:At the first follow-up 12% had quit smoking. In the year prior to the second follow-up this rate had increased to 23%. Parental smoking and being recruited in Dresden reduced the propensity to quit while parental allergic disease increased it. Presence of respiratory symptoms did not affect quitting. Smoking cessation reduced the risk for cough and for wheeze without a cold at the second follow-up by 50% to 85%. Statistical significance depended on the definition of symptoms and age at smoking cessation. The strongest effect was RR 0.13 (0.02;0.95) for incident cough. In general, smoking cessation also reduced the risk of persistent respiratory symptoms, however, this effect did not reach statistical significance. Conclusion:Despite relatively low numbers, our study shows clear benefit from smoking cessation for respiratory health in young adults.