Study design: A prospective, repeated-measures cohort design with high school students from Montreal, Canada.
Objectives: To determine whether smoking was a risk factor for the development of low back pain or other musculoskeletal pain in a cohort of adolescents.
Summary of background data: Smoking has been associated with low back pain in adults. Many adolescents smoke, and the prevalence of low back pain in this age group is 30%. A history of low back pain is predictive of future problems.
Methods: A total of 502 students from grades 7 to 9 were assessed from 3 schools. Data were collected at 3 times: at the beginning of the study, at 6 months, and at the end of a 12-month period. Students responded to a questionnaire addressing musculoskeletal health and life-style factors, which included smoking. Measurements of height, weight, trunk and leg flexibility, and trunk strength were obtained. Low back pain occurring at a frequency of at least once a week in the past 6 months was defined as the outcome. Multivariate methods were used to model the repeated-measures dichotomous outcome as a function of smoking and other covariates.
Results: Smokers experienced low back pain more than nonsmokers (odds ratio, 2.4; 95% confidence interval, 1.3-6.0). There was also a dose-response relationship between amount smoked and development of low back pain. Smokers tended to experience more upper limb or lower limb pain than nonsmokers, although this result was not significant.
Conclusions: Smoking was found to increase the risk for low back pain in this cohort of adolescents.