Table 3.

Incident Hip Fracture Within One Year Among Patients Initiating Tramadol Comparing with Initiation of One of Two Commonly Used Nonselective NSAIDs (Naproxen, Ibuprofen) or One of Two Cyclooxygenase-2 Inhibitors (Celecoxib, Etoricoxib)

	Nonselective NSAIDs
	Tramadol vs. Naproxen		Tramadol vs. Ibuprofen
Participants (n)	115,109	115,109	107,438	107,438
Incident hip fracture (n)	313	185	349	212
Mean follow-up (years)	0.95	0.96	0.95	0.96
Rate (/1000 person-years)*	2.9	1.7	3.4	2.0
RD (/1000 person-years, 95% CI)	1.2 (0.8, 1.6)	0.0 (reference)	1.4 (0.9, 1.8)	0.0 (reference)
	Cyclooxygenase-2 Inhibitors
	Tramadol vs. Celecoxib		Tramadol vs. Etoricoxib
Participants (n)	43,130	43,130	27,689	27,689
Incident hip fracture (n)	142	77	78	40
Mean follow-up (years)	0.96	0.98	0.96	0.98
Rate (/1000 person-years)	3.4	1.8	2.9	1.5
RD (/1000 person-years, 95% CI)	1.6 (0.9, 2.3)	0.0 (reference)	1.5 (0.7, 2.3)	0.0 (reference)

NSAIDs, non-steroidal anti-inflammatory drugs; n, number; RD, rate difference; 95% CI, 95% confidence interval.

^*Number (rate) of competing event (i.e., death) in comparison of tramadol and naproxen group was 3,418 (31.2/1000 person-years) and 1,431 (12.9/1000 person-years), in comparison of tramadol and ibuprofen group was 3,958 (38.9/1000 person-years) and 1,977 (19.1/1000 person-years), in comparison of tramadol and celecoxib group was 1,776 (43.3/1000 person-years) and 751 (17.8/1000 person-years), in comparison of tramadol and etoricoxib group was 877 (33.1/1000 person-years) and 366 (13.5/1000 person-years), respectively.