Population-based Risk Factors for the Development of Degenerative Disk Disease.

Study Design: This is a retrospective case control study.

Objective: Identify risk factors and assess their relative impact on the development of degenerative disk disease (DDD).

Summary Of Background Data: DDD is responsible for widespread disability in the civilian and military population. Despite the impact of low back pain and DDD, its multifactorial etiology is not entirely understood.

Materials And Methods: The Defense Medical Surveillance System was searched for military members with the diagnosis of DDD as identified with the use of International Classification of Disease, 9th Revision (ICD-9) codes. These patients were compared with an age-matched and sex-matched control of military members without DDD from the Defense Medical Surveillance System. The prevalence of risk factors (obesity, hip, and knee osteoarthritis, tobacco dependence, diabetes, and type of employment) was then determined for both groups. In total, 160,911 patients with DDD were identified compared with 315,225 controls. Multivariate conditional logistical regression analysis was utilized to determine odds ratio (OR) for these groups based on data matched by age and sex and were adjusted for military rank and race/ethnicity.

Results: Diabetes showed an OR of 1.469 [confidence interval (CI), 1.350-1.598]. Hip and knee arthritis produced an OR of 2.925 (CI, 2.685-3.187) and tobacco dependency showed an OR of 1.799 (CI, 1.762-1.836). The comparison of overweight to normal body mass index produced an OR of 1.334 (CI, 1.307-1.361) and the analysis of obese to normal body mass index had an OR of 1.556 (CI, 1.497-1.618). There failed to be a clinically significant association between military duty assignments and the presence of DDD.

Conclusions: Our research failed to show a clinical significance association between military duty assignment and DDD. However, we were able to identify a significant association between concomitant hip and knee osteoarthritis, obesity, diabetes, and tobacco dependency with the development of DDD.

Level Of Evidence: Level IV.