Can health care utilization explain the association between socioeconomic status and back pain?

Study Design: Cross-sectional population-based study.
Objectives: To assess whether the association between socioeconomic status and severe back pain can be explained by the preceding health care utilization for back pain.
Summary of Background Data: The ways in which socioeconomic status affects the occurrence of back pain are unclear.
Methods: Age- and gender-adjusted odds ratios with 95% confidence intervals for the association between indicators of socioeconomic status and severe current back pain (high intensity and/or high disability: no/yes) were investigated in an interview among 770 study participants out of 1113 study participants with a recent history of back pain in a survey among 2731 adults.
Results: The point prevalence of severe current back pain (39.8%) was related to educational level and health insurance status. Prior health care utilization for back pain was about 2-fold more prevalent in adults with severe current back pain. Members of private health insurance (odds ratio 0.60, 95% confidence interval 0.37-0.99) were less likely to report prior consultation of a general practitioner for back pain. Members of sick funds for white-collar workers (odds ratio 2.81, 95% confidence interval 1.43-5.51) and private insurance (odds ratio 2.81, 95% confidence interval 1.02-6.24) and individuals with intermediate educational level (odds ratio 1.76, 95% confidence interval 1.05-2.95) utilized more physical therapy for the treatment of back pain. After additionally adjusting for health care utilization, the associations between educational level or health insurance status and severe current back pain remained unchanged.
Conclusions: The data suggest that education, health insurance status, and health care utilization are independently associated with severe current back pain in a society with universal access to health care.