Risk of hip/femur fractures during the initiation period of α-adrenoceptor blocker therapy among elderly males: a self-controlled case series study.
OBJECTIVE
This study aimed to evaluate the risk of hip/femur fractures during the initiation period of α-adrenoceptor blocker therapy using the National Health Insurance claims database, Taiwan, with a self-controlled case series design.


METHODS
All male beneficiaries aged over 50 years as of 2007, who were incident users of α-adrenoceptor blockers and also had a diagnosis of hip/femur fracture within the 2007-2009 study period were identified. The first day when the α-adrenoceptor blocker was prescribed was set as the index date. We partitioned the initial 21 day period following the index date as the post-exposure risk period 1, days 22-60 after the index date as the post-exposure risk period 2, the 21 day period prior to the index date as the pre-exposure risk period 1 and days 22-60 prior to the index date as the pre-exposure risk period 2. The remainder of the study period was defined as the unexposed period. The incidence rate ratio (IRR) of hip/femur fractures within each risk period compared with the unexposed period was estimated using a conditional Poisson regression model.


RESULTS
A total of 5875 men were included. Compared with the unexposed period, the IRR of hip/femur fractures was 1.36 (95% confidence interval 1.06, 1.74, P = 0.017) within the post-exposure risk period 1 for patients without concomitant prescriptions of anti-hypertensive agents.


CONCLUSIONS
Use of α-adrenoceptor blockers was associated with a small but significant increase in the risk of hip/femur fractures during the early initiation period in patients without concomitant prescriptions of anti-hypertensive agents.
Department of Internal Medicine and Center for Critical Care Medicine, National Taiwan University Hospital Hsin-Chu Branch, Hsin-Chu.|Department of Internal Medicine, College of Medicine, National Taiwan University, Taipei.|Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei.
Chao-Lun
http://orcid.org/0000-0002-0362-245X
CL
Lai
Institute of Health Policy and Management, College of Public Health, National Taiwan University, Taipei.|Center for Comparative Effectiveness Research, National Center of Excellence for Clinical Trial and Research, National Taiwan University Hospital, Taipei.
Raymond Nien-Chen
RN
Kuo
Center for Comparative Effectiveness Research, National Center of Excellence for Clinical Trial and Research, National Taiwan University Hospital, Taipei.
Ho-Min
HM
Chen
Department of Internal Medicine, National Taiwan University Hospital, Taipei.
Ming-Fong
MF
Chen
Department of Medical Research, National Taiwan University Hospital, Taipei.|Graduate Institute of Oncology, College of Medicine, National Taiwan University, Taipei, Taiwan.
Kinwei Arnold
KA
Chan
Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei.|Center for Comparative Effectiveness Research, National Center of Excellence for Clinical Trial and Research, National Taiwan University Hospital, Taipei.
Mei-Shu
MS
Lai
D000317:Adrenergic alpha-Antagonists / Q000008:administration & dosage* / Q000009:adverse effects*; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D016208:Databases, Factual; D005264:Femoral Fractures / Q000139:chemically induced / Q000453:epidemiology*; D006620:Hip Fractures / Q000139:chemically induced / Q000453:epidemiology*; D006801:Humans; D008297:Male; D012307:Risk Factors; D013624:Taiwan / Q000453:epidemiology; D013997:Time Factors
D000317:Adrenergic alpha-Antagonists
adrenergic α1-receptor antagonists; femoral fractures; hip fractures; self-controlled case series design