Fortin et al. (8) | Observational; longitudinal | Preoperative to 6 mo after hip replacement | n = 116, undergoing total hip replacement for osteoarthritis | Compared 6-mo outcomes between those with “high” (better) and “low” (worse) function preoperatively | SF-36 physical function score,* WOMAC pain score,† WOMAC functional limitation score,‡ hip range of motion: mean difference (high–low) (95% CI) 16.4 (7.3 to 25.5), −1.9 (−3.0 to −0.7), −5.9 (−9.7 to −2.1), 12.8°, respectively (i.e., worse 6-mo status among those with worse function preoperatively). |
Garbuz et al. (9) | Observational; longitudinal | From placement on waiting list to 1 yr after hip replacement | n = 147, undergoing total hip replacement for osteoarthritis | Examined probability of achieving better than expected outcome at 1 yr based on “long” (> 6 mo) v. “short” (≤ 6 mo) wait and by count of months on waiting list from decision to proceed with surgery to operation | Better than expected v. not better than expected WOMAC outcomes. 43% of patients with short waits v. 31% of those with long waits achieved better than expected functional outcome. Those with long waits had 50% decreased odds for achieving a better than expected outcome compared with those with short waits. Each additional month spent waiting was associated with an 8% decreased odds (adjusted OR 0.92, p = 0.05) of better than expected functional outcome. No evidence of negative effect of wait time found for WOMAC pain and stiffness domains. |
Vergara et al. (10) | Observational; longitudinal | Preoperative to 6 mo after hip replacement | n = 527, undergoing total hip replacement for osteoarthritis | Examined predictors of change in WOMAC domains over 6 mo, and predictors of achieving minimal clinically important difference on WOMAC domains, including presurgery status and wait time | WOMAC pain score, WOMAC functional limitation score, WOMAC stiffness score.§ Change in function was poorer (p = 0.025) among those who waited > 6 mo for surgery. Progressive reduction in % of patients surpassing minimal clinically important difference with increasing wait time; 74% v. 68% v. 52% for those waiting < 3 mo, 3–6 mo and > 6 mo, respectively (p < 0.001). Likelihood of perceiving a gain greater than minimal clinically important difference was lower (OR 0.47, p = 0.006) with > 6 mo wait compared with < 3 mo wait. No effects on other WOMAC domains observed. |
Hajat et al. (11) | Observational; longitudinal | Preoperative to 12 mo after hip replacement | n = 3600 at 12 mo, undergoing total hip replacement (87.8% had osteoarthritis as primary diagnosis) | Examined predictors of 12-mo Oxford Hip Score status, including presurgery status and wait time | Oxford Hip Score¶ (measure of severity of hip problems: pain, disability, loss of physical function). Trend of worse 12-mo status with worse presurgery status (p < 0.001), longer wait to first outpatient appointment (p < 0.001) and longer time on wait list (p < 0.001). |
Fortin et al. (12) | Observational; longitudinal | Preoperative to 2 yr after hip replacement | n = 84, undergoing total hip replacement for osteoarthritis (subset of sample from Fortin et al. (8) who completed 2-yr survey) | Compared 6-mo outcomes between those with “high” (better) and “low” (worse) function preoperatively | SF-36 physical function score,* WOMAC pain score,† WOMAC functional limitation score‡: mean difference (high–low) (95% CI) 14.7 (2.6 to 26.8), −1.5 (−3.1 to 0.1), −6.6 (−11.8 to −1.4), respectively (i.e., worse 2-yr status among those with worse function preoperatively). |