Dataset Information

Mapping analyses to estimate EQ-5D utilities and responses based on Oxford Knee Score.

ABSTRACT:

Purpose

The Oxford Knee Score (OKS) is a validated 12-item measure of knee replacement outcomes. An algorithm to estimate EQ-5D utilities from OKS would facilitate cost-utility analysis on studies analyses using OKS but not generic health state preference measures. We estimate mapping (or cross-walking) models that predict EQ-5D utilities and/or responses based on OKS. We also compare different model specifications and assess whether different datasets yield different mapping algorithms.

Methods

Models were estimated using data from the Knee Arthroplasty Trial and the UK Patient Reported Outcome Measures dataset, giving a combined estimation dataset of 134,269 questionnaires from 81,213 knee replacement patients and an internal validation dataset of 45,213 questionnaires from 27,397 patients. The best model was externally validated on registry data (10,002 observations from 4,505 patients) from the South West London Elective Orthopaedic Centre. Eight models of the relationship between OKS and EQ-5D were evaluated, including ordinary least squares, generalized linear models, two-part models, three-part models and response mapping.

Results

A multinomial response mapping model using OKS responses to predict EQ-5D response levels had best prediction accuracy, with two-part and three-part models also performing well. In the external validation sample, this model had a mean squared error of 0.033 and a mean absolute error of 0.129. Relative model performance, coefficients and predictions differed slightly but significantly between the two estimation datasets.

Conclusions

The resulting response mapping algorithm can be used to predict EQ-5D utilities and responses from OKS responses. Response mapping appears to perform particularly well in large datasets.

SUBMITTER: Dakin H

PROVIDER: S-EPMC3607737 | biostudies-literature | 2013 Apr

REPOSITORIES: biostudies-literature

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Publications

Mapping analyses to estimate EQ-5D utilities and responses based on Oxford Knee Score.

Dakin Helen H Gray Alastair A Murray David D

Quality of life research : an international journal of quality of life aspects of treatment, care and rehabilitation 20120504 3

<h4>Purpose</h4>The Oxford Knee Score (OKS) is a validated 12-item measure of knee replacement outcomes. An algorithm to estimate EQ-5D utilities from OKS would facilitate cost-utility analysis on studies analyses using OKS but not generic health state preference measures. We estimate mapping (or cross-walking) models that predict EQ-5D utilities and/or responses based on OKS. We also compare different model specifications and assess whether different datasets yield different mapping algorithms. ...[more]

PMID: 22555470

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Project description:BackgroundThe degree to which a validated instrument is able to detect clinically significant change over time is an important issue for the better management of hip or knee replacement surgery. This study examines the internal responsiveness of the EQ-5D-3L, the Oxford Hip Score (OHS), and the Oxford Knee Score (OKS) by various methods. Data from NHS patient-reported outcome measures (PROMs) linked to the Hospital Episodes Statistics (HES) dataset (2009-2015) was analysed for patients who underwent primary hip surgery (N = 181,424) and primary knee surgery (N = 191,379).MethodsPaired data-specific univariate responsiveness was investigated using the standardized response mean (SRM), the standardized effect size (SES), and the responsiveness index (RI). Multivariate responsiveness was furthermore examined using the defined capacity of benefit score (i.e. paired data-specific MCID), adjusting baseline covariates such as age, gender, and comorbidities in the Box-Cox regression models. The observed and predicted percentages of patient improvement were examined both as a whole and by the patients' self-assessed transition level.ResultsThe results showed that both the OHS and the OKS demonstrated great univariate and multivariate responsiveness. The percentages of the observed (predicted) total improvement were high: 51 (54)% in the OHS and 73 (58)% in OKS. The OHS and the OKS showed distinctive differences in improvement by the 3-level transition, i.e. a little better vs. about the same vs. a little worse. The univariate responsiveness of the EQ-5D-3L showed moderate effects in total by Cohen's thresholds. The percentages of improvement in the EQ-5D-3L were moderate: 44 (48)% in the hip and 42 (44)% for the knee replacement population.ConclusionsDistinctive percentage differences in patients' perception of improvement were observed when the paired data-specific capacity of benefit score was applied to examine responsiveness. This is useful in clinical practice as rationale for access to surgery at the individual-patient level. This study shows the importance of analytic methods and instruments for investigation of the health status in hip and/or knee replacement surgery. The study finding also supports the idea of using a generic measure along with the disease-specific instruments in terms of cross-validation.

Project description:BackgroundThe EQ-5D-5?L is a quality-of-life questionnaire based on individuals' preferences that is widely employed for cost-effectiveness analysis. Given the current demand for mapping algorithms to directly assign "utilities", this study aimed to generate different mapping models for predicting EQ-5D-5?L utility values based on scores of the Oxford Hip Score (OHS) and Oxford Knee Score (OKS) questionnaires provided by patients suffering from hip and knee osteoarthritis (OA), respectively, and to assess the predictive capability of these functions.MethodsThis was a prospective, observational study. Following the criteria of the American Rheumatism Association, 361 patients with hip OA and 397 with knee OA from three regions in Spain were included. Health-related quality of life (HRQoL) was assessed through the EQ-5D-5?L general questionnaire and the OHS and OKS specifically for lower limb OA. Based on the scores on the OHS and OKS questionnaires, EQ-5D-5?L utilities were estimated using 4 models: ordinary least squares (OLS), Tobit, generalized linear model (GLM), and beta regression (Breg). The models were validated on the same patients after 6?months: the mean absolute error (MAE) and mean squared error (MSE) with their 95% confidence intervals (CI), mean values of standard errors (SE), intraclass correlation coefficients (ICC), and Bland-Altman plots were obtained.ResultsThe lowest MAEs were obtained using GLM and Breg models, with values of 0.1103 (0.0993-0.1214) and 0.1229 (0.1102-0.1335) for hip OA, and values of 0.1127 (0.1014-0.1239) and 0.1141 (0.1031-0.1251) for knee OA. MSE values were also lower using GLM and Breg. ICCs between predicted and observed values were around or over the 0.8 cut-off point. Bland-Altman plots showed an acceptable correlation, but precision was lower for subjects with worse HRQoL, which was also evident when comparing MAEs of the bottom and top halves of the utilities scale. Predictive equations for utilities based on OHS/OKS scores were proposed.ConclusionsThe OHS and OKS scores allow for estimating EQ-5D-5?L utility indexes for patients with hip and knee OA, respectively, with adequate validity and precision. GLM and Breg produce the best predictions. The predictive power of proposed equations is more consistent for subjects in better health condition.

Project description:BACKGROUND:The objective of this study was to obtain utilities by means of EQ-5D-5L for different health states in patients with knee osteoarthritis (KOA) or hip osteoarthritis (HOA) in Spain, and to compare these values with those used in foreign studies with the aim of discussing their transferability for their use in economic evaluations conducted in Spain. METHODS:Primary study: Observational prospective study of KOA or HOA patients in Spain. Sociodemographic and clinical characteristics were collected to characterize the sample. Utilities were elicited using the EQ-5D-5L questionnaire. ANOVA and bivariable analyses were conducted to identify differences between health states. LITERATURE REVIEW:Using the bibliographic databases NSH EED and CEA Registry, we conducted searches of model-based cost utilities analyses of technologies in KOA or HOA patients. Health states and utilities were extracted and compared with values obtained from the Spanish sample. RESULTS:Three hundred ninety-seven subjects with KOA and 361 subjects with HOA were included, with average utilities of 0.544 and 0.520, respectively. In both samples, differences were found in utilities according to level of pain, stiffness and physical function (WOMAC) and severity of symptoms (Oxford scales), so that the worst the symptoms, the lower the utilities. The utilities after surgery were higher than before surgery. Due to limitations from our study related to sample size and observational design, it was not possible to estimate utilities for approximately half the health states included in the published models because they were directly related to specific technologies. For almost 100% of health states of the selected studies we obtained very different utilities from those reported in the literature. CONCLUSIONS:To our knowledge this is the first article with detailed utilities estimated using the EQ-5D-5L in Spain for KOA and HOA patients. In both populations, utilities are lower for worse health states in terms of level of pain, stiffness and physical function according to WOMAC, and according to the Oxford scales. Most utilities obtained from the Spanish sample are lower than those reported in the international literature. Further studies estimating utilities from local populations are required to avoid the use of foreign sources in economic evaluations.

Project description:Limited utility data on patients suffering from overactive bladder (OAB) are available in the literature. The objectives of this study were to estimate utility values in patients with OAB using the generic EQ-5D questionnaire and the OAB-5D disease specific questionnaire, to investigate the relationship between utilities and symptoms, and to evaluate the sensitivity of the two instruments to changes in symptom severity.Analyses were based on pooled data from three large multicenter randomized 12-week placebo-controlled trials (SCORPIO, ARIES, CAPRICORN). Patients completed a micturition diary, EQ-5D and OAB-q (a quality of life questionnaire from which OAB-5D is derived) at baseline and at weeks 4, 8 and 12. Time trade-off tariffs elicited from UK population were applied to obtain utilities from both instruments. Repeated measures regressions were used to estimate EQ-5D and OAB-5D utilities by micturition frequency and incontinence severity level. As a test of sensitivity of the instruments, utility changes from baseline to week 12 were estimated by symptomatic response (improvement, stable or worsening).The sample included 4427 patients. Mean utilities (± standard deviation) across all visits were 0.82 (± 0.21) for EQ-5D and 0.86 (±0.09) for OAB-5D. Correlation between EQ-5D and OAB-5D was 0.34 (p < 0.0001). Both OAB-5D and EQ-5D utilities increased as OAB symptoms improved. Utility values were similar for severe levels of symptoms, but higher with OAB-5D than with EQ-5D for mild cases. Micturitions and incontinence had similar impact on EQ-5D utilities, but micturitions had greater impact on OAB-5D utilities than incontinence. Changes from baseline in OAB-5D utilities differed significantly according to symptomatic response. Changes in EQ-5D utilities were not significantly associated with changes in micturition frequency and weakly associated with changes in incontinence severity among patients with mild symptoms at baseline.This study showed that both EQ-5D and OAB-5D can detect changes in severity of OAB, especially in severe cases. However, OAB-5D is more sensitive than EQ-5D in measuring differences between treatments in milder cases. Both OAB-5D and EQ-5D-although leading to different results-may be useful to derive utilities from clinical trial data and perform cost-effectiveness analyses.Clinical Trials NCT00689104, NCT00662909, NCT00912964.

Dataset Information

Mapping analyses to estimate EQ-5D utilities and responses based on Oxford Knee Score.

Purpose

Methods

Results

Conclusions

Publications

Mapping analyses to estimate EQ-5D utilities and responses based on Oxford Knee Score.

Similar Datasets

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