Retrospective analysis of nationwide Veterans Health Administration (VA) clinical and administrative data.
Examine the association between HIV infection and the rate of spine surgery for degenerative spine disease.
Summary of Background Data
Combination anti-retroviral therapy (cART) has prolonged survival in patients with HIV/AIDS, increasing the prevalence of chronic conditions such as degenerative spine disease that may require spine surgery.
We studied all HIV infected patients under care in the VA from 1996–2008 (n=40,038) and uninfected comparator patients (n=79,039) matched on age, gender, race, year, and geographic region. The primary outcome was spine surgery for degenerative spine disease defined by ICD-9 procedure and diagnosis codes. We used a multivariate Poisson regression to model spine surgery rates by HIV infection status, adjusting for factors that might affect suitability for surgery (demographics, year, comorbidities, body mass index, cART, and laboratory values).
Two-hundred twenty eight HIV infected and 784 uninfected patients underwent spine surgery for degenerative spine disease during 700,731 patient-years of follow-up (1.44 surgeries per 1,000 patient-years). The most common procedures were spinal decompression (50%), and decompression and fusion (33%); the most common surgical sites were the lumbosacral (50%), and cervical (40%) spine. Adjusted rates of surgery were lower for HIV infected patients (0.86 per 1,000 patient-years of follow-up) than for uninfected patients (1.41 per 1,000 patient-years; IRR 0.61, 95% CI: 0.51, 0.74, P<0.001). Among HIV infected patients, there was a trend towards lower rates of spine surgery in patients with detectable viral loads levels (IRR 0.76, 95% CI: 0.55, 1.05, P=0.099).
In the VA, HIV infected patients experience significantly reduced rates of surgery for degenerative spine disease. Possible explanations include disease prevalence, emphasis on treatment of non-spine HIV-related symptoms, surgical referral patterns, impact of HIV on surgery risk-benefit ratio, patient preferences, and surgeon bias.