Table 4

Odds ratios for selected characteristics and 30-day postoperative mortality following total hip arthroplasty, by high- and low-volume hospitals

CharacteristicHospital volume; OR (95% CI)
High-volume, R2 = 0.21, n = 5605Low-volume, R2 = 0.26, n = 1490
Provider volume1.00 (0.99–1.01)0.99 (0.96–1.03)
Patient age, yr1.05 (1.03–1.07)1.04 (1.00–1.08)
Patient sex (female v. male)0.63 (0.43–0.93)0.47 (0.21–1.04)
Admission category (urgent v. elective)5.07 (2.90–8.85)11.26 (3.09–40.99)
Patient comorbidity (level vs. none)
 12.85 (1.59–5.12)7.18 (2.87–17.93)
 23.50 (2.02–6.04)2.84 (0.76–10.59)
 35.35 (2.89–9.89)3.52 (0.73–16.99)
 413.58 (7.34–25.13)39.69 (6.73–234.24)
 Missing/not applicable1.43 (0.50–4.05)5.46 (1.41–21.16)
Neighbourhood income quintile (v. lowest)
 Medium-low1.31 (0.75–2.29)0.62 (0.22–1.77)
 Middle0.94 (0.51–1.74)0.74 (0.25–2.20)
 Medium-high1.24 (0.73–2.11)0.81 (0.28–2.32)
 Highest0.89 (0.48–1.65)0.96 (0.28–3.26)
Community size (v. city [population 100 000 to 499 000])
Small town (population 10 000 to 99 999)1.27 (0.74–2.19)
Rural area (population < 10 000)1.47 (0.98–2.20)
  • CI = confidence interval; OR = odds ratio.