Introduction: The NHS Contract for Acute Services (April 2008), includes a requirement in Schedule 5 to report on patient reported outcome measures (PROMS). This sets out national standards for elective patients undergoing Primary Unilateral Total Hip Replacements (THR) and Total Knee Replacements (TKR). The recommended instruments for these procedures are the Oxford Hip and Knee Scores. Our aim was to assess whether these instruments accurately assess patient satisfaction and pain and whether a more efficient model could be used.
Methods: All patients undergoing primary THR and TKR under the care of the senior author (DH) between Sept 07 – Sept 09 at the RHC Hospital were included in the study. The primary diagnosis in all patients was Osteo-arthritis. All Patients were operated on by DH using the same approach, implants and post-operative rehabilitation programme. Patients were assessed at 6 weeks, 6 months and 1 year post-operatively using the Oxford-12 joint specific score and also by a Visual Analogue Scale (VAS) for pain and satisfaction. The Oxford-12 and VAS scores were then compareded against one another for correlation using scatter-plots and regression analysis.
Results:
Primary TKR:
At 6 weeks: Correlation for OKS and pain, OKS and satisfaction, Pain and satisfaction were r = 0.782, 0.736 and 0.796 respectively (p<
0.001)
At 6 months: Correlation for OKS and pain, OKS and satisfaction, Pain and satisfaction were r = 0.718, 0.749 and 0.767 respectively (p<
0.001)
At 1 year: Correlation for OKS and pain, OKS and satisfaction, Pain and satisfaction were r = 0.7, 0.703 and 0.793 respectively (p<
0.001) Primary THR:
At 6 weeks: Correlation for OHS and pain, OHS and satisfaction, Pain and satisfaction were r = 0.361, 0.309 and 0.477 respectively (p<
0.001)
At 6 months: Correlation for OHS and pain, OHS and satisfaction, Pain and satisfaction were r = 0.596, 0.673 and 0.635 respectively (p<
0.001)
At 1 year: Correlation for OHS and pain, OHS and satisfaction, Pain and satisfaction were r = 0.682, 0.636 and 0.862 respectively (p<
0.001)
Conclusion: The Oxford-12 site specific score correlates extremely well with both VAS scores for pain and patient satisfaction at all time points post-operatively with all values showing a significant (p <
0.001) positive association. Similarly, pain and patient satisfaction scores demonstrate a strong positive association. We propose that rather than using the Oxford-12 score as part of the PROMS assessment, a simple VAS for pain and satisfaction would provide adequate information and would be easier for patients to complete.