Table 3

Risk of hip fracture by time since first prescription for bisphosphonates

 CasesControlsAverage cumulative duration (days)Time since first BP prescription (days)Model 1Model 2
n (%)n (%)Mean (SD)Mean (SD)OR (95% CI)OR (95% CI)
Time since first BP use
 >30 days to ≤1 year41 (14.5)222 (18.4)157 (133)194 (103)1 (ref)1 (ref)
 >1  to ≤3 years120 (42.4)546 (45.2)535 (451)727 (209)1.23 (0.68 to 2.23)1.49 (0.71 to 3.13)
 >3 years122 (43.1)439 (36.4)1138 (873)1618 (445)1.79 (0.94 to 3.40)2.21 (0.96 to 5.09)
 p for trend*0.030.03
  • Model 1: Conditional logistic regression model.

  • Model 2: Conditional logistic regression model adjusted for smoking, body mass index, alcoholism, previous fracture, kidney disease, malabsorption, stroke, dementia, rheumatoid arthritis, diabetes, epilepsy, Parkinson's disease, and thyroid disease, PPI (no use, ≤1 year, >1 year), anxiolytics, sedatives, antidepressants, antihypertensives, oral corticosteroids (no use, ≤1 year, >1 year), raloxifene, hormone replacement therapy and thiazolidinediones.

  • *Modelled as time in days since first bisphosphonate prescription.

  • BP, bisphosphonate.