title: Rasch scoring of outcomes of total hip replacement.
abstract: We examined whether there are advantages in terms of outcome assessment of using Rasch methods of scoring the 12-item Oxford Hip Score questionnaire over conventionally summed scores. Data were collected on patients receiving total hip replacement surgery. Three patient groups were created according to surgery type: primary, revision, and re-revision; two groups were created according to satisfaction with surgery: very satisfied and dissatisfied. Analyses were performed to test the relative precision (RP) of Rasch scoring versus conventionally summed scores in discriminating the groups experiencing different types of surgery and level of satisfaction. At the 1-year follow-up, RP ratios favored the Rasch scoring method in both tests of discrimination. Considerable gains in precision were achieved with Rasch scoring methods when groups were compared in a cross-sectional way. Alternative approaches to scoring questionnaires should be investigated to better assess comparisons over time.
authors.affiliation: Department of Public Health, Institute of Health Sciences, University of Oxford, Headington, Oxford OX3 7LF, United Kingdom. raymond.fitzpatrick@nuffield.oxford.ac.uk
authors.forename: Ray
authors.initials: R
authors.lastname: Fitzpatrick
authors.forename: Josephine M
authors.initials: JM
authors.lastname: Norquist
authors.forename: Jill
authors.initials: J
authors.lastname: Dawson
authors.forename: Crispin
authors.initials: C
authors.lastname: Jenkinson
mesh_terms: D000203:Activities of Daily Living; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000523:psychology* / Q000534:rehabilitation; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D006304:Health Status; D006801:Humans; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000209:etiology; D010147:Pain Measurement; D017060:Patient Satisfaction; D011184:Postoperative Period; D011594:Psychometrics; D011788:Quality of Life; D012680:Sensitivity and Specificity; D011795:Surveys and Questionnaires / Q000592:standards*; D016896:Treatment Outcome