Antipsychotic use and the risk of hip/femur fracture: a population-based case-control study.
This case-control study showed that current use of conventional antipsychotics, but not atypical antipsychotics, seems to be associated with an increased risk of a hip/femur fracture, possibly related to the pharmacological properties of conventional antipsychotics. Furthermore, no evidence for a dose effect was found.


BACKGROUND
The aim of this study was to assess the risk of hip/femur fracture associated with antipsychotic use, with particular reference to any difference in risk with conventional versus atypical antipsychotics, dose, and pharmacological properties.


METHODS
A case-control study was conducted using data from the PHARMO Record Linkage System among individuals aged 18 years and older between 1991 and 2002. Cases had a record of a hip or femur fracture, while controls had no evidence of ever having sustained any fracture.


RESULTS
Most cases were elderly (77.6% aged > or = 70 years). We found an increased risk for hip/femur fracture associated with the use of antipsychotic drugs. The risk for current users (OR(adj) 1.68 [1.43, 1.99]) was significantly greater than with past use (OR(adj) 1.33 [1.14, 1.56]; p = 0.036). Current use of conventional antipsychotics (OR(adj) 1.76 [1.48, 2.08]) but not atypical antipsychotics (OR(adj) 0.83 [0.42, 1.65]) was associated with an increased risk. We did not find evidence for a dose effect.


CONCLUSIONS
The use of conventional, but not atypical antipsychotics, seems to be associated with an increased risk of hip/femur fracture, possibly related to the pharmacological properties of conventional antipsychotics. However, the numbers of atypical antipsychotic users were small, and therefore this observation needs further attention in other study populations.
Pouwels
S
S
Department of Pharmacoepidemiology and Pharmacotherapy, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands. sanderpouwels@hotmail.com
van Staa
T P
TP
Egberts
A C G
AC
Leufkens
H G M
HG
Cooper
C
C
de Vries
F
F
D000293:Adolescent; D000328:Adult; D000368:Aged; D014150:Antipsychotic Agents / Q000009:adverse effects*; D016022:Case-Control Studies; D005260:Female; D005264:Femoral Fractures / Q000139:chemically induced* / Q000453:epidemiology; D006620:Hip Fractures / Q000139:chemically induced* / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D016017:Odds Ratio; D012307:Risk Factors; D055815:Young Adult
D014150:Antipsychotic Agents