Lipid-lowering agents and the risk of hip fracture in a Medicaid population.
BACKGROUND
Three recent nested case-control studies conducted in automated databases suggest that users of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) have a risk of hip and other osteoporotic fractures half that of non-users of any lipid-lowering drug. However, this comparison may be biased by unmeasured factors associated with treated hyperlipidemias.


OBJECTIVE
To compare the risk of hip fracture among users of statins and other lipid-lowering agents, which is less susceptible to bias than the comparisons performed in the previous studies.


METHODS
Retrospective cohort study conducted in the Tennessee Medicaid program between 1 January 1989 through 31 December 1998.


METHODS
New users of all lipid-lowering drugs and randomly selected non-user controls who at baseline were at least 50 years of age and did not have life threatening illness, nursing home residence, or diagnosed dementia or osteoporosis. There were 12506 persons with new use of statins, 4798 with new use of other lipid lowering drugs, and 17280 non-user controls.


METHODS
Fracture of the proximal femur (hip), excluding pathological fractures or those resulting from severe trauma.


RESULTS
During 66690 person years of follow up, there were 186 hip fractures (2.8 per 1000). Relative to non-users, the adjusted incidence rate ratios (95% confidence interval) were 0.62 (0.45 to 0.85) for statin users and 0.44 (0.26 to 0.95) for other lipid-lowering drugs. When compared directly with the other drugs, the adjusted incidence rate ratio for statins was 1.42 (0.83-2.43).


CONCLUSIONS
These data provide evidence that the previously observed protective effect of statins may be explained by unmeasured confounding factors.
Ray
W A
WA
Department of Preventive Medicine, Vanderbilt University School of Medicine and the Geriatric Research, Education and Clinical Center, Nashville VAMC, Nashville, Tennessee 37232, USA. wayne.ray@mcmail.vanderbilt.edu
Daugherty
J R
JR
Griffin
M R
MR
D000368:Aged; D015331:Cohort Studies; D003625:Data Collection; D005260:Female; D006620:Hip Fractures / Q000453:epidemiology / Q000517:prevention & control*; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000627:therapeutic use*; D015994:Incidence; D008297:Male; D008484:Medicaid; D008875:Middle Aged; D010024:Osteoporosis / Q000453:epidemiology / Q000517:prevention & control*; D012189:Retrospective Studies; D012307:Risk Factors; D013714:Tennessee / Q000453:epidemiology
D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors