Table 1.

Summary of included cohort studies examining the association of bisphosphonate use and subtrochanteric, femoral shaft, and atypical femur fractures

Study, year, country	Subjects	Type of bisphosphonate	Outcome definition and number of events	Variables matched and/or controlled	Quality assessment scores b
Abrahamsen a, 2009, Denmark 27	15,561 women with history of non-hip fracture in a national patient registry (1997–2005)	Alendronate	ST/FS fractures 76	Matched on: Sex, birth year, baseline fracture location Adjusted for: Age, sex, and comorbidities	s3/c2/o2
Abrahamsen a, 2010, Denmark 28	197,835 patients without previous hip fracture in a national patient registry (1996–2005)	Alendronate	ST/FS fractures 1049	Matched on: Age, sex, index year Adjusted for: Sex, Charlson index, hormone therapy, steroid use, fracture history, and number of co-medications	s4/c2/o1
Black, 2010, USA 12	14,195 women enrolled in three randomized controlled trials examining bisphosphonate use	Alendronate Zoledronic acid	ST/FS fractures 12	Placebo-controlled	s3/c2/o2
Hsiao, 2011, Taiwan 14	11,278 women with osteoporosis and prior vertebral/hip fracture in a national insurance database (2001–2007)	Alendronate	ST/FS fractures 61	Adjusted for: Age, fracture history, comorbidities, and co-medications	s3/c2/o1
Kima, 2011, USA 13	33,815 new-users of bisphosphonates, raloxifene, or calcitonin enrolled in Medicare (1996–2006)	Alendronate Etidronate Risedronate	ST/FS fractures 104	Matched on: Propensity score (encompassing age, race, sex, health care utilization, comorbidities, and co-medications)	s3/c2/o1
Vestergaard, 2011, Denmark 11	414,245 patients from a national patient registry (1996–2006)	Alendronate Etidronate Clodronate Ibandronate Pamidronate Risedronate Zoledronic acid	ST/FS fractures 4,179	Matched on: Age, sex Adjusted for: Steroid use, hormone therapy, alcoholism, fracture history	s3/c2/o2

AFF, atypical femur fractures; ST, subtrochanteric; FS, femoral shaft. All studies used International Statistical Classification of Diseases to identify cases, either 8th, 9th or 10th revision, and/or medical record review to identify cases

^aThese studies examined risk associated with bisphosphonate use ≥ 5 years

^bMaximum score using the Newcastle-Ottawa Scale¹⁶ is s4/c2/o3. The scoring system is based on selection of cohorts (s), comparability of cohorts (c), and outcome assessment criteria (o).