The Number of Patients and Therapeutic Profile of Spinal Stenosis Using Health Insurance Claims in Japan.

STUDY DESIGN Population-based retrospective descriptive study. OBJECTIVE To describe the number and therapeutic profile of patients with spinal stenosis at a large-scale community level using health insurance claims data. SUMMARY OF BACKGROUND DATA A few reports have documented the prevalence of spinal stenosis, and no report has described the therapeutic profile for spinal stenosis in a population base. METHODS We studied the claims data of National Health Insurance and Late-stage Elderly Health Insurance in a prefecture in Japan from April 2010 to March 2011. We considered patients to have spinal stenosis if their claims included at least one diagnosis coded as spinal stenosis for at least 1 month during the study period. Disease criteria were based on the International Classification of Diseases, 10th version. We then described the number and the therapeutic profile of the patients with spinal stenosis by age and sex. RESULTS Of 699,723 beneficiaries, 52,889 patients with spinal stenosis were identified. The number of patients with spinal stenosis per 1000 beneficiaries was 76, and those for the subgroups of age ≥ 65 years, ≥ 75 years, and ≥ 85 years were 128, 155, and 152, respectively. The number of patients per 1000 beneficiaries showed unimodal distribution, and the peak for males was 191 between the ages 95 to 99 years and that for females was 160 between the ages 80 to 84 years. Analgesics, prostaglandin E1, or both were prescribed to 40%, 2%, or 20% of patients with spinal stenosis, respectively. Physical therapy, nerve blocks, and surgery were done for 19%, 8%, and 0.4% of the patients, respectively. Approximately, 33% of patients did not receive any treatment. CONCLUSION There were a large number of patients with spinal stenosis in elderly people. Most of them received nonsurgical treatments. Health insurance claims data could be a useful source of surveillance for such common diseases as spinal stenosis. LEVEL OF EVIDENCE 4.