Prevalence of lumbar spinal stenosis, using the diagnostic support tool, and correlated factors in Japan: a population-based study

Background Few studies have examined the prevalence of lumbar spinal stenosis (LSS) in the general population. The purposes of this study were to estimate the prevalence of LSS and to investigate correlated factors for LSS in Japan. Methods A questionnaire survey was performed on 4,400 subjects selected from residents aged 40-79 years in Japan by stratified two-stage random sampling in 2010. The question items consisted of lower-limb symptoms suggestive of LSS, the diagnostic support tool for LSS (LSS-DST), demographic and lifestyle characteristics, comorbidities, the Japanese Perceived Stress Scale (JPSS), and the Mental Health Index 5 (MHI-5). Using the LSS-DST, the presence of LSS was predicted to estimate the prevalence of LSS. Logistic regression analysis was performed to examine the relationship between LSS and correlated factors. Results Questionnaires were obtained from 2,666 subjects (60.6 %), consisting of 1,264 males (47.4 %). The mean (standard deviation) age was 60.0 (10.9) years. According to the LSS-DST, 153 subjects were regarded as having LSS. The prevalence was estimated to be 5.7 %. When standardizing this value with the age distribution of the Japanese population, it was estimated that 3,650,000 Japanese subjects aged 40-79 years might have LSS using the LSS-DST. Prevalence increased with age and was particularly high in subjects aged 70-79 years, irrespective of gender. As correlated factors, an advanced age (60 years or older), diabetes mellitus, urological disorders, and osteoarthritis/fracture as comorbidities, and depressive symptoms, were associated with LSS. Conclusions This study elucidated the prevalence of LSS and factors associated with LSS in Japan. This is the first report describing the estimated prevalence of LSS and associated factors using a strictly sampled representative population.