Association of social support with patient-reported outcomes after joint replacement: a systematic review and meta-analysis

Background Identifying prognostic factors for outcomes after joint replacement could improve the provision of stratified care. We investigated whether social support is a prognostic factor for improved patient-reported outcomes after total hip replacement or total knee replacement. Methods For this systematic review and meta-analysis, we searched MEDLINE, Embase, and PsycINFO from inception to April 5,2019. Cohort studies investigating the association between social support and patient-reported outcomes at 3 months or longer after total hip replacement or total knee replacement were eligible for inclusion. Patient-reported outcomes were pain, function, satisfaction, and general health, which were evaluated predominantly with the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Oxford Knee Score, and 36-item short form health survey (SF-36) questionnaires. Data were extracted from published articles and results of relevant statistical analyses requested from authors where not available. Data were synthesised by use of meta-analysis and narrative synthesis. This study is registered on PROSPERO, CRD42016041485. Findings We identified 5810 articles, and 56 studies with data from 119165 patients were included (13 in the meta-analysis, 43 in the narrative synthesis). In the meta-analysis, the presence of social support had a beneficial effect on the long-term postoperative WOMAC (2022 patients; mean difference 2.88 [95% CI 1.30 to 4.46]) and Oxford Knee Score (69570 patients; 0.29 [042 to 0.45]) in the fixed-effects model. Social support measured by use of a validated questionnaire was found to be associated with WOMAC pain (671 patients; mean difference 0.04 [95% CI 0.00 to 0.08]) in the fixed-effects model but not with WOMAC function (671 patients; -0.011-0.12 to 0.111) in the random-effects model. The presence of social support had a positive association with some SF-36 subscales but not others. For all outcomes, results of the narrative synthesis were inconsistent. Interpretation Social support appears to be a prognostic factor for some outcomes after joint replacement. The development and evaluation of complex interventions to improve social support and social integration is warranted in patients who have undergone joint replacement surgery. Copyright (C) 2019 Elsevier Ltd. All rights reserved.