Risk for fractures with centrally acting muscle relaxants: an analysis of a national Medicare Advantage claims database.
BACKGROUND
In older adults, both muscle relaxants and benzodiazepines are associated with sedation and cognitive impairment. Although benzodiazepines have been linked to falls and fracture injuries, no studies have examined the risk of fracture associated with muscle relaxants.


OBJECTIVE
To determine whether muscle relaxants identified in the Beers criteria are associated with an increased risk of fracture injuries and to compare this risk to that with benzodiazepine use.


METHODS
We conducted a case-control study using both medical and pharmacy claims data from 1.5 million enrollees in the Medicare Advantage plans of a large health maintenance organization. We matched 8164 cases of fractures with 8164 controls based on age, sex, health plan, and comorbidities. We measured the use of muscle relaxants, short-acting benzodiazepines, and long-acting benzodiazepines. Adjusted odds ratios were estimated using conditional logistic regression.


RESULTS
After adjusting demographic and clinical covariates, muscle relaxants, long-acting benzodiazepines, and short-acting benzodiazepines were associated with a high risk of fracture injuries, with odds ratios of 1.40 (95% CI 1.15 to 1.72; p < 0.001), 1.9 (95% CI 1.49 to 2.43; p < 0.001), and 1.33 (95% CI 1.15 to 1.55; p < 0.001), respectively.


CONCLUSIONS
An elevated risk of fracture injuries was noted among older adults using muscle relaxants. Our findings provide evidence of an association between the risk of fractures and the use of centrally acting muscle relaxants in older adults. This association supports current recommendations advising extreme caution in prescribing muscle relaxants to older adults.
Golden
Adam G
AG
Geriatrics Institute, Miller School of Medicine, University of Miami, Miami, FL, USA. adam.golden@va.gov
Ma
Qianli
Q
Nair
Vinit
V
Florez
Hermes J
HJ
Roos
Bernard A
BA
D000058:Accidental Falls / Q000706:statistics & numerical data*; D000368:Aged; D000369:Aged, 80 and over; D001569:Benzodiazepines / Q000009:adverse effects; D016022:Case-Control Studies; D016208:Databases, Factual; D005260:Female; D050723:Fractures, Bone / Q000139:chemically induced* / Q000453:epidemiology; D006801:Humans; D008297:Male; D016555:Matched-Pair Analysis; D020398:Medicare Part C / Q000706:statistics & numerical data*; D009125:Muscle Relaxants, Central / Q000009:adverse effects*; D012306:Risk; D014481:United States
D009125:Muscle Relaxants, Central; D001569:Benzodiazepines