Prevalence of and Risk Factors for Back Pain Among Young Male Conscripts During Compulsory Finnish Military Service

Back pain is a major reason for sick leaves and disability pension in primary health care. The prevalence of back pain among adolescents and young adults is believed to be increasing, and back pain during military service predicts unspecified back pain during later life. The aim of this study was to investigate the prevalence and risk factors of back pain among conscripts in compulsory Finnish military service during the period 1987-2005.

The Finnish Defence Forces recruit all men aged 18 years for compulsory military service, and new conscripts enter the service twice a year. Before entering the service, all conscripts must pass a medical examination and conscripts entering the service are generally healthy.Health care in Finnish military service is organized by the public Garrison Health Center, and all medical records are stored as part of the Finnish health care operation plan. For this study, we randomly selected 5,000 men from the Finnish Population Register Centre, according to their year of birth from five different age categories (1969, 1974, 1979, 1984, and 1989).

We gathered 4,029 documents for the analysis. The incidence of back pain varied between 18% and 21% and remained unchanged during the examination period. The risk factors for back pain were smoking (risk ratio 1.35, P-value <.001), elementary school only as education (risk ratio 1.55, P-value <.001), and back problems reported before military service (risk ratio 2.03, P-value .002). Half of the back pain incidences occurred during the first months of service.

The prevalence of back pain among male Finnish military service conscripts has not changed in the last 25 years. Twenty percent of conscripts suffer from back-related problems during their military service. The majority of the visits to health centers occurred in the first service months. The risk factors for back pain include smoking, low education level, and musculoskeletal disorders in general. Educating the young people about harms of tobacco and supporting education is a way to influence the back pain prevalence. Strength of this study is a good generalized population sample of young Finnish adult males because of the fact that the Finnish military service is compulsory for all men. All medical records of all visits to the Garrison Health Care Centre were available, and all the conscripts filled the same pre-service questionnaire, minimizing the possibility of selection bias. The sample size was also large. Weakness of this study is that the service time changed during the study period and in the latest conscript group born in 1989, data collection and the data available for this cohort was limited, because nearly half of the conscripts had not yet started their service. The Finnish military service is compulsory only for men and because of the low number of female conscripts, they were excluded from this study. Diagnoses were also missing from 70% of the back-related visits, and these visits were recorded as back pain-related visits according to the reason for seeking care.