The Forgotten Joint Score (FJS) is a 12-item patient reported outcome measurement instrument. It was developed with classical test theory, without testing assumptions such as unidimensionality (all items reflect one underlying factor), appropriate weighting of each item, no differential item function (DIF, different groups answer the same way), and monotonicity (people with higher function have higher score). We applied item response theory (IRT) to improve the validity of FJS to contemporary standards to optimise it for ongoing use. Does the FJS reflect one latent trait? Can an IRT model be fitted to the FJS to provide interval-scaled measurement?Abstract
Background
Research Questions
This study investigates whether primary knee arthroplasty (KA) restores health-related quality of life (HRQoL) to levels expected in the general population. This retrospective case-control study utilises two sources: patients undergoing primary KA from a University Teaching hospital; and individual-level data from the Health Survey for England which was used to represent the General Population. Propensity score matching was used to balance covariates (sex, age and body mass index (BMI)) and facilitate group comparisons. Two matched cohorts with 3029 patients each were obtained for the adjusted analyses (median age 70.3 interquartile range (IQR) 64–77; Female sex 3233 (53.4%); median BMI 29.7 IQR 26.5-33.7). HRQoL was measured using the three-level version of the EuroQol 5-Dimensions’ (EQ-5D-3L) Index and EQ-VAS scores.Abstract
INTRODUCTION
METHODOLOGY
The aims of this study were to assess mapping models to predict the three-level version of EuroQoL five-dimension utility index (EQ-5D-3L) from the Oxford Knee Score (OKS) and validate these before and after total knee arthroplasty (TKA). A retrospective cohort of 5,857 patients was used to create the prediction models, and a second cohort of 721 patients from a different centre was used to validate the models, all of whom underwent TKA. Patient characteristics, BMI, OKS, and EQ-5D-3L were collected preoperatively and one year postoperatively. Generalized linear regression was used to formulate the prediction models.Aims
Methods
Up to 20% of patients are not satisfied with the outcome following total knee replacement (TKR), but little is known about the predictors of this dissatisfaction. This study investigated the pre- and post-operative predictors of dissatisfaction in a large cohort of patients undergoing TKR. We assessed 1217 consecutive patients undergoing TKR between 2006 and 2008 both preoperatively and six months after surgery, using the Short-form (SF)-12 health questionnaire and the Oxford Knee Score. Detailed co-morbidity information was also gathered. Satisfaction was measured at one year and 18.6% (226 of 1217) of patients were unsure or dissatisfied with their replacement, 81.4% (911 of 1217) were satisfied or very satisfied. Multivariate regression analysis was performed to identify independent predictors of dissatisfaction. Significant (p < 0.001) predictors of dissatisfaction at one year included the pre-operative SF-12 mental component score, the co-morbidities of depression and pain in other joints, and the six-month SF-12 score. The most significant independent predictor of dissatisfaction at 1 year was poor improvement in Oxford Knee Score pain element at 6 months. Patient expectations were highly correlated with satisfaction. Satisfaction following TKR is multifactorial. Managing patient expectations and mental health may reduce dissatisfaction rates. However, the most significant predictor of dissatisfaction is a painful total knee replacement.
