Judge A, Batra R N, Thomas G E, Beard D, Javaid M K, Murray D W, Dieppe P A, Dreinhoefer K E, Peter-Guenther K, Field R, Cooper C, Arden N K
Oxford NIHR Musculoskeletal Biomedical Research Unit, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Windmill Road, Headington, Oxford OX3 7LD, UK; MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton General Hospital, Southampton SO16 6YD, UK.
Oxford NIHR Musculoskeletal Biomedical Research Unit, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Windmill Road, Headington, Oxford OX3 7LD, UK.
Osteoarthritis Cartilage. 2014 Mar;22(3):431-9. doi: 10.1016/j.joca.2013.12.018. Epub 2014 Jan 11.
To describe whether body mass index (BMI) is a clinically meaningful predictor of patient reported outcomes following primary total hip replacement (THR) surgery.
Combined data from prospective cohort studies. We obtained information from four cohorts of patients receiving primary THR for osteoarthritis: Exeter Primary Outcomes Study (EPOS) (n = 1431); EUROHIP (n = 1327); Elective Orthopaedic Centre (n = 2832); and St. Helier (n = 787). The exposure of interest was pre-operative BMI. Confounding variables included: age, sex, SF-36 mental health, comorbidities, fixed flexion, analgesic use, college education, OA in other joints, expectation of less pain, radiographic K&L grade, ASA grade, years of hip pain. The primary outcome was the Oxford Hip Score (OHS). Regression models describe the association of BMI on outcome adjusting for all confounders.
For a 5-unit increase in BMI, the attained 12-month OHS decreases by 0.78 points 95%CI (0.27-1.28), P-value 0.001. Compared to people of normal BMI (20-25), those in the obese class II (BMI 35-40) would have a 12-month OHS that is 2.34 points lower. Although statistically significant this effect is small and not clinically meaningful in contrast to the substantial change in OHS seen across all BMI groupings. In obese class II patients achieved a 22.2 point change in OHS following surgery.
Patients achieved substantial change in OHS after THR across all BMI categories, which greatly outweighs the small difference in attained post-operative score. The findings suggest BMI should not present a barrier to access THR in terms of PROMs.
描述体重指数（BMI）是否是初次全髋关节置换（THR）手术后患者报告结局的具有临床意义的预测指标。
前瞻性队列研究的合并数据。我们从四组因骨关节炎接受初次THR的患者中获取信息：埃克塞特主要结局研究（EPOS）（n = 1431）；欧洲髋关节置换研究（EUROHIP）（n = 1327）；择期骨科中心（n = 2832）；以及圣赫利尔医院（n = 787）。感兴趣的暴露因素是术前BMI。混杂变量包括：年龄、性别、SF-36心理健康评分、合并症、固定屈曲度、镇痛药物使用情况、大学学历、其他关节的骨关节炎、对疼痛减轻的期望、放射学K&L分级、美国麻醉医师协会（ASA）分级、髋关节疼痛年限。主要结局是牛津髋关节评分（OHS）。回归模型描述了在对所有混杂因素进行校正后BMI与结局之间的关联。
BMI每增加5个单位，12个月时的OHS降低0.78分，95%置信区间（0.27 - 1.28），P值为0.001。与正常BMI（20 - 25）的人相比，II级肥胖（BMI 35 - 40）者12个月时的OHS低2.34分。尽管具有统计学意义，但与所有BMI分组中OHS的显著变化相比，这种影响较小且无临床意义。II级肥胖患者术后OHS变化了22.2分。
所有BMI类别的患者在THR术后OHS均有显著变化，这大大超过了术后得分的微小差异。研究结果表明，就患者报告结局而言，BMI不应成为接受THR的障碍。
