Risk of stroke after chiropractic spinal manipulation in medicare B beneficiaries aged 66 to 99 years with neck pain

J Manipulative Physiol Ther. 2015 Feb;38(2):93-101. doi: 10.1016/j.jmpt.2014.12.001. Epub 2015 Jan 14.

Abstract

Objective: The purpose of this study was to quantify risk of stroke after chiropractic spinal manipulation, as compared to evaluation by a primary care physician, for Medicare beneficiaries aged 66 to 99 years with neck pain.

Methods: This is a retrospective cohort analysis of a 100% sample of annualized Medicare claims data on 1 157 475 beneficiaries aged 66 to 99 years with an office visit to either a chiropractor or primary care physician for neck pain. We compared hazard of vertebrobasilar stroke and any stroke at 7 and 30 days after office visit using a Cox proportional hazards model. We used direct adjusted survival curves to estimate cumulative probability of stroke up to 30 days for the 2 cohorts.

Results: The proportion of subjects with stroke of any type in the chiropractic cohort was 1.2 per 1000 at 7 days and 5.1 per 1000 at 30 days. In the primary care cohort, the proportion of subjects with stroke of any type was 1.4 per 1000 at 7 days and 2.8 per 1000 at 30 days. In the chiropractic cohort, the adjusted risk of stroke was significantly lower at 7 days as compared to the primary care cohort (hazard ratio, 0.39; 95% confidence interval, 0.33-0.45), but at 30 days, a slight elevation in risk was observed for the chiropractic cohort (hazard ratio, 1.10; 95% confidence interval, 1.01-1.19).

Conclusions: Among Medicare B beneficiaries aged 66 to 99 years with neck pain, incidence of vertebrobasilar stroke was extremely low. Small differences in risk between patients who saw a chiropractor and those who saw a primary care physician are probably not clinically significant.

Keywords: Chiropractic; Medicare; Neck Pain; Spinal Manipulation, Adverse Effects; Stroke; Vertebral Artery Dissection.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Age Factors
  • Aged
  • Aged, 80 and over
  • Cohort Studies
  • Female
  • Follow-Up Studies
  • Humans
  • Male
  • Manipulation, Chiropractic / adverse effects*
  • Manipulation, Chiropractic / methods
  • Manipulation, Spinal / adverse effects*
  • Manipulation, Spinal / methods
  • Medicare / economics
  • Medicare / statistics & numerical data
  • Neck Pain / diagnosis
  • Neck Pain / rehabilitation*
  • Proportional Hazards Models
  • Retrospective Studies
  • Risk Assessment
  • Severity of Illness Index
  • Sex Factors
  • Stroke / epidemiology*
  • Stroke / etiology
  • Stroke / physiopathology
  • Time Factors
  • United States