Knee osteoarthritis (OA) is a debilitating and costly chronic health condition affecting approximately 10% of Canadians. Total Knee Arthroplasty (TKA) is an effective procedure restoring quality of life and providing pain relief for patients with knee OA. The benefits of TKA are well established for patients with knee OA, but determining those who would most benefit is a challenging task. Physical functioning in patients with knee OA has been shown to be a key factor for appropriateness for TKA. The Lower Extremity Functional Scale (LEFS) and the Oxford Knee Score (OKS) are two patient-reported outcome measures (PROMs) measuring physical function that can be utilized to assist health care professionals in determining the need for TKA among this population. The LEFS is a regional PROM consisting of 20 questions asking about activities relating to lower extremity functioning. Questions are scored on a 5-point descriptive scale from 0 (extreme difficulty or unable to perform the activity) to 4 (no difficulty) with a total score of 80. Higher scores represent higher functioning. The OKS is a site-specific PROM that asks questions about pain and function and consists of 12 items ranked on a 5-point descriptive scale. Scores range from 1 to 5 (total score of 60) for each item with lower scores representing higher function.
The purpose of this thesis was to determine the diagnostic accuracy for the LEFS and the OKS for determining appropriateness for TKA in people with primary knee OA. The hypothesis for the current study was that the LEFS would have higher diagnostic accuracy for appropriateness for TKA compared to the OKS. A cross-sectional retrospective study of patients with knee OA attending a Regional Joint Assessment Program (RJAP) from January to September 2013 was conducted. Classification of appropriateness for TKA was determined by the attending orthopedic surgeon’s decision at the end of the assessment. Diagnostic accuracy for the OKS and the LEFS were determined using the area under the curve (AUC) of the receiver operator characteristic (ROC) curve. Cut-off scores were calculated for both outcome measures.
Four hundred and twenty one patients eligible for the study (41.8% males; 66.9 years old) completed the OKS and the LEFS. The diagnostic accuracy for the OKS and the LEFS was determined using the AUC of the ROC curve for each patient-reported measure using Stata ® version 12.1. The cut-off scores were determined as the point on the ROC curve yielding the best sensitivity and specificity for the two outcome measures. The results showed the LEFS did not have higher diagnostic accuracy (LEFS AUC = 0.686 (95% CI = 0.636 – 0.736); OKS AUC = 0.674 (95% CI = 0.623- 0.724)) for determining appropriateness for TKA in patients with primary knee OA in isolation. The best cut-off score for those deemed appropriate for TKA among patients with knee OA was 26 out of 80 LEFS points and 42 points out of 60 OKS points.
The results of this thesis agree with previous research reporting that decision-making regarding the need for TKA in patients with knee OA is multi-factorial. Our data confirm that this decision cannot be based on patient-reported physical function alone. Factors other than or in addition to patient-reported lower limb physical functioning should be considered when determining which patients with knee OA would most benefit from TKA. Further research evaluating these factors is warranted to improve triage services for patients with knee OA most likely to benefit from TKA. / Thesis / Master of Science Rehabilitation Science (MSc)
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/16411 |
| Date | 18 November 2014 |
| Creators | Gavin, Sherri |
| Contributors | Norma, MacIntyre, Rehabilitation Science |
| Source Sets | McMaster University |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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