Decision trees for indication of total hip replacement on patients with osteoarthritis.

OBJECTIVE: To develop a decision tree based on health-related quality of life outcomes rather than expert consensus for determining the appropriateness of total hip replacement (THR) among patients with hip OA. METHODS: This is a prospective observational study of two independent cohorts. The derivation cohort included 590 patients recruited from seven hospitals between March 1999 and March 2000. The validation cohort included 339 patients recruited from six hospitals between September 2003 and September 2004. Socio-demographic and clinical data were collected for the participants, all of whom completed the WOMAC before hip replacement and 6 months later. Univariate and Regression Trees, by classification and regression trees (CART), analyses were performed in the derivation cohort. The decision trees derived in the derivation cohort were validated in the validation cohort. RESULTS: Main variables that predicted change in the WOMAC pain and functional limitation domains were pre-intervention pain or functional limitation and the application of non-surgical treatments. CART analysis showed that when pre-intervention pain was classified as minor, or WOMAC pain or functional limitation scores were < or = 40, there was an odds ratio of 0.076 (95% CI 0.031, 0.185) of having an expected gain after THR in the WOMAC pain domain of > 30 or > 25 in the WOMAC functional limitation domain. CONCLUSIONS: A simple decision tree based on WOMAC outcomes can help to determine the appropriate application of THR. It could also be used to evaluate clinical practice or for quality control.

Prevalence of knee and hip osteoarthritis and the appropriateness of joint replacement in an older population.

BACKGROUND: Relatively little is known about the prevalence of knee and hip osteoarthritis in the general population. METHODS: To estimate the prevalence of knee and hip osteoarthritis and the appropriateness of joint replacement in a general population of older individuals, the validated Knee and Hip OsteoArthritis Screening Questionnaire (KHOA-SQ) was sent to a random sample of individuals aged 60 to 90 years, stratified by age and sex, living in a single province in Spain. Respondents positive for knee or hip osteoarthritis on the KHOA-SQ were invited to be examined by an orthopedic surgeon. Diagnosis of knee or hip osteoarthritis was based on clinical and radiographic data. For respondents judged as having osteoarthritis, the appropriateness of knee or hip replacement was evaluated using published explicit criteria. RESULTS: Of 11 002 individuals contacted, 7577 completed the KHOA-SQ. The derived prevalence of hip osteoarthritis was approximately 7.4%. It was slightly higher in women (8.0%) than in men (6.7%) and tended to increase with age. The estimated appropriateness rate for hip replacement was 37.7% in men and 52.7% in women with osteoarthritis. The derived prevalence of knee osteoarthritis was 12.2%; it was significantly higher in women (14.9%) than in men (8.7%) and tended to increase with age. The estimated appropriateness rate for knee replacement was 11.8% in men and 17.9% in women with osteoarthritis. CONCLUSIONS: Knee and hip osteoarthritis are highly prevalent diseases in the older population. The estimation of appropriateness for hip replacement seems to be significantly higher than that for knee replacement.

Development of explicit criteria for prioritization of hip and knee replacement.

RATIONALE AND AIMS: Among the problems to the publicly funded national health services are the waiting lists. Patients who need elective surgery generally have long waiting times before treatment. We aimed to develop a new prioritization tool for primary hip and knee replacement. METHODS: Criteria were developed using a modified Delphi panel process. We convened a panel of nine members who scored the scenarios created by the research team and by patient focus groups. We studied the level of agreement among the panelists and the contribution of the variables to the ratings of the panel using linear and logistic regression models. The priority scores of the variables and their levels were synthesized using the optimal scaling and standard linear regression methods. RESULTS: Seven variables, pain on motion, walking functional limitations, abnormal findings on physical examination, pain at rest, other functional limitations, social role, and other pathologies that could improve with joint replacement, were considered to create the different scenarios. The panel scored 192 scenarios. The disagreement among the panelists was very low (1%) with an intra-class correlation coefficient of 0.72. Of the 192 scenarios, 45.8% were scored as urgent, 35.4% as preferred and 18.8% as ordinary. The variables that contributed most to the scores were pain on motion and walking functional limitations. When optimal scaling and regression techniques were applied, similar results were obtained. CONCLUSION: This tool can evaluate and prioritize patients on a waiting list for hip or knee replacement. We also provide a simple and easy way to use an algorithm to estimate the treatment priority for individual patients.

Health-related quality of life and appropriateness of knee or hip joint replacement.

BACKGROUND: We studied the association between explicit appropriateness criteria for total hip joint replacement (THR) and total knee replacement (TKR) with changes in health-related quality of life of patients undergoing these procedures. METHODS: Prospective observational study of 1576 consecutive patients with diagnoses of osteoarthritis on waiting lists to undergo THR or TKR. Explicit appropriateness criteria using the RAND appropriateness method were applied. Patients completed 2 questionnaires that measured health-related quality of life, the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), before the procedure and 6 months afterward. RESULTS: Patients who were considered appropriate candidates for these procedures had greater improvements than those who were considered inappropriate candidates in all 3 WOMAC domains (pain, functional limitation, and stiffness; THR: 43.0, 40.6, and 40.4 vs 14.7, 19.1, and 15.9; TKR: 34.9, 32.5, and 30.2 vs 23.2, 18.9, and 17.1; P<.001 for all comparisons). Patients who underwent THR and were judged to be appropriate candidates had greater improvements in the physical function, role-physical, bodily pain, and social function domains of the SF-36 than those judged to be inappropriate candidates (34.4, 35.1, 33.1, and 26.6 vs 19.6, 9.2, 5.7, and 7.0; P = .04, P = .03, P < .001, and P < .001, respectively). Appropriate candidates for TKR demonstrated greater improvement in the social function domain of the SF-36 after the procedure than those deemed inappropriate candidates (19.9 vs 7.9; P = .004) but not in the other domains of functional status. CONCLUSIONS: These results suggest a direct relationship between explicit appropriateness criteria and better health-related quality-of-life outcomes after THR and TKR surgery. Our results support the use of these criteria for clinical guidelines or evaluation purposes.

Appropriateness of total hip joint replacement.

OBJECTIVE: To evaluate the appropriateness of the use of total hip joint replacements. DESIGN: Observational study of consecutive patients with a diagnosis of hip osteoarthritis and who had undergone total hip arthroplasty over a 1-year period from seven hospitals. MAIN MEASURES: The appropriateness of the use of hip replacement was judged by explicit criteria developed by a panel of experts using RAND methodology. The length of hospital stay during the admission and complications were recorded 6 months post-operatively. Patients were also surveyed 6 months after discharge to determine whether they believed they had recovered or their satisfaction with the intervention. Appropriateness results of this study were compared with a previous study performed with the same criteria 4 years previously. RESULTS: In total, 784 patients participated in the study. Indications for surgery were considered necessary in 52.2% of cases, appropriate in 21.3%, uncertain in 21.4%, and inappropriate in 5.1%. Differences were found in the rates of appropriateness exclusively from one hospital. At 6 months after discharge, differences between centres were found for the proportion of patients that reported they had recovered from surgery (range 57.7-24.8%) and in the length of hospital stay during admission (range 10-16 days). Improvement in the appropriateness rates were found for all participant hospitals during both periods. CONCLUSIONS: We identified a low percentage of inappropriate indications and differences in some outcomes between centres. Compared with previously, there has been improvement in the use of this technique, although both periods are not methodologically comparable.

Development of explicit criteria for total knee replacement.

OBJECTIVES: To develop and test an appropriateness of indications tool for total knee replacement (TKR) in patients with osteoarthritis. METHODS: Criteria were developed using a modified Delphi panel judgment. Another panel rated the same indications, and the results were compared with the main panel. Test-retest of the main panel was performed. Regression models were used to assess the contribution of each algorithm variable. A classification tree was developed. RESULTS: The procedure was considered appropriate in 167 (26.8%) scenarios, and there was agreement on 112 (67.1%) of them. When the rates of the main panel were compared with those of a second panel, the result was a kappa statistic of 0.75. The test-retest kappa for the main panel was 0.78. Neither in the first case nor in the second was there an instance in which a scenario classified as appropriate shifted to inappropriate or vice versa. The regression models showed that symptomatology and radiology were the variables that explained most of the variability of appropriateness as determined by panelists. In the classification tree performed, the probability of misclassification was 3.8% with 150 scenarios, of the 156 analyzed and classified correctly. CONCLUSIONS: The previous parameters tested showed acceptable results for an evaluation tool. These results support the use of this algorithm as an aid in formulating clinical practice guidelines and to promote the appropriateness of TKR.

Use of explicit criteria for total hip joint replacement fixation techniques.

We developed a tool to judge the appropriateness of indications and fixation mechanisms for total hip joint replacement (THJR) and applied it to a sample of patients. Criteria were developed using a modified Delphi panel judgment process, following the RAND methodology (RAM). We recruited, during 1 year, patients with a diagnosis of osteoarthritis undergoing THJR in five public hospitals. The appropriateness of the THJR intervention and the fixation mechanism was judged by the explicit criteria developed by a panel of experts. Of the 216 scenarios scored by the panel for the use of each of three fixation mechanisms, the cemented fixation was considered inappropriate in 69.5%, versus just 33.3% for the non cemented. Of those scenarios considered appropriate, the most appropriate mechanism of fixation was considered to be non cemented (74.4%), while cemented (17.8%) and hybrid (7.8%) scenarios were scored as appropriate less often. The previous explicit criteria were applied to 583 real patients. After evaluation of the interventions, 30% of the fixation mechanisms used were considered appropriate, while 21.8% inappropriate. Appropriate use of fixation mechanisms varied among hospitals. RAM can provide explicit criteria to help in clinical decision making and evaluating indications for a THJR intervention. Nevertheless, in the case of the appropriateness of fixation mechanisms, due to the lack of evidence, the panel criteria were biased towards the non cemented technique, which had important implications for the evaluation of some hospitals.