Abstract
Background
Oxford joint scores are increasingly being used in evaluating outcomes following orthopaedic surgery. These patient-reported outcome measures (PROM) have been well validated, but only before and after surgical intervention. We postulated that the scores would deteriorate in the normal population with age.
Methods
Members of the public accompanying patients to out-patients and the emergency department in our hospitals were asked to complete an Oxford score questionnaire having ascertained that they had no previous problem with that joint. Exclusions included other multiple joint pathologies and known connective tissue disorders. Power analysis advocated 40 subjects per decade per joint for significance at the 80% mark. 993 subjects between 20 and 80 years of age completed the forms. There were more females than males. The scores were analysed using STATA 8 software. Non-parametric tests of variance, regression analysis, and ANOVA were used. The data were analysed by decades.
Results
In all joints (hip, knee, shoulder, and elbow) the mean Oxford score in the 20-30 year olds (third decade) was at least one point below the maximum. The scores then deteriorated with age at the rate of one point per decade. This was statistically significant in all groups (p = 0.002 or less) Sex had no statistical influence on the scores.
Conclusion
In our mainly (98%) Caucasian population the Oxford Scores deteriorate with age. We suggest that this should be taken into account when cohort studies are being compared between surgeons and units, especially in units dealing with many younger patients. Oxford scores should be age adjusted, starting at the 3rd decade by adding 1 point for the 3rd decade, 2 for the fourth, etc. up to 6 points for the eighth decade. Other ethnic groups should also be studied.
