Racial differences in the incidence of acute low back pain in United States military service members.

STUDY DESIGN

An epidemiological study.

OBJECTIVE

To determine the effect of race on the incidence of acute low back pain, resulting in a health care encounter in active duty military service members.

SUMMARY OF BACKGROUND DATA

Although racial differences in the incidence of low back pain have been documented in previous studies, currently no consensus exists on the relative risk between these groups.

METHODS

A query was performed using the Armed Forces Health Surveillance Center database for the International Classification of Diseases, Ninth Revision code for low back pain (724.20). A total of 12,399,276 person-years of data were analyzed and stratified by age, race, and sex. Incidence rates were calculated and compared using the multivariate Poisson regression analysis.

RESULTS

A total of 467,950 cases of low back pain resulted in a visit to a health care provider in our population, with an overall incidence rate of 37.74 per 1000 person-years. Asians/Pacific Islanders had the lowest incidence rate of 30.7 and blacks had the highest with 43.7. Female sex and older age were also significant risk factors but with significantly different effect sizes between racial groups. Native Americans/Alaskan Natives demonstrated the greatest effect of age on low back pain incidence rates, with a 126% increase between the youngest and oldest age groups compared with a 36% difference in whites.

CONCLUSION

Race, sex, and age were all found to be significant risk factors for acute low back pain. The highest rates were identified in blacks followed by whites, Hispanics, and American Indian/Alaskan Native, and the lowest rates were identified in Asians/Pacific Islanders. Significant differences in the effect of sex and age were identified between the different racial groups.