Table 3.

Sample size calculations comparing total hip arthroplasty (THA) and hemiarthroplasty (HA)

Study	THA reoperation rate	HA reoperation rate
van den Bekerom et al31	5/110 (4.5%)	1/136 (0.7%)
Baker et al32	4/36 (11.1%)	2/39 (5.1%)
Blomfeldt et al33	4/56 (7.1%)	3/57 (5.3%)
Keating et al34	6/63 (9.5%)	5/64 (7.8%)
Macaulay et al35	1/16 (6.25)	0/23 (0%)

Studies included in a meta-analysis comparing THA with HA for the outcome of reoperation at 1 year.

THA versus HA combined effect: fixed and random, relative risk=1.67 (95% CI 0.86 to 3.24), p=0.13.

Pooled event rates: THA fixed and random, incidence rate=7.8% (95% CI 5.2 to 11.6).

HA fixed, incidence rate=5.3% (95% CI 3.2 to 8.9).

HA random, incidence rate=4.9% (95% CI 2.6 to 9.2).