Abstract
OBJECTIVE: The purpose of this study was to evaluate the risk of selected adverse outcomes for older adults with a new episode of neck pain (NP) receiving chiropractic care compared to those receiving primary medical care with Prescription Drug Therapy (PDT) or primary care without medication. METHODS: Through analysis of Medicare claims data, we designed a retrospective cohort study including 291 604 patients with a new office visit for NP in 2019. We developed 3 mutually exclusive exposure groups: the Chiropractic Manipulative Therapy (CMT) group received spinal manipulative therapy from a chiropractor with no primary care visits; the PDT group visited primary care and filled an analgesic prescription within 7 days without chiropractic care, and the Primary Care Only (PCO) group visited primary care without chiropractic care or analgesic prescriptions. We analyzed possible complications, including adverse drug events, vertebrobasilar insufficiency, and other selected adverse outcomes, calculating incidence rate ratios over 24 months using Poisson regression with robust standard errors and inverse propensity weighing to balance the exposure groups regarding patient characteristics. RESULTS: Among 291 604 patients, 182 596 (63%) received chiropractic care. For CMT vs PDT, the rate for any measured adverse outcome was 20% lower; for CMT vs PCO, the rate was 14% lower, and for PDT vs PCO, the rate was 6% higher. PDT had the highest risk of any measured adverse outcome. CONCLUSION: For Medicare Part B beneficiaries with new onset NP, management with chiropractic care was associated with lower rates of adverse events than primary medical care. The PDT group had the highest risk of any measured adverse outcome.