Oxford score MCID

Meaningful changes for the Oxford hip and knee scores after joint replacement surgery

Beard DJ, Harris K, Dawson J, et al. Journal of clinical epidemiology 2015 · PMID 25441700 · doi:10.1016/j.jclinepi.2014.08.009

Question

What change in Oxford hip and knee scores after joint replacement is meaningful to patients?

Design

Secondary analysis of the national NHS PROMs dataset using anchor-based and distribution-based methods.

Patients

Large national cohorts of patients listed for primary hip or knee replacement in the NHS PROMs programme.

Intervention

Anchor-based estimation using patient-reported global change

Comparison

Distribution-based estimates

Primary outcome

Minimal important change and minimal important difference for OHS and OKS

Key result

Group-level minimal important change was roughly 11 points for the OHS and 9 for the OKS (about 8 and 7 points for individual patients), whereas the between-group minimal important difference for trials was about 5 points for both scores.

Limitations

Thresholds vary with the method and anchor used and the population studied, so a single cut-off should not be applied rigidly.

Impact on practice

These values are used to power UK arthroplasty trials and to judge whether a statistically significant difference in Oxford scores is clinically relevant.