Computer-assisted decision analysis in orthopedics: resurfacing the patella in total knee arthroplasty as an example

The purpose of the present study was to illustrate the use of computer-assisted decision analysis in making decisions in the field of orthopaedic surgery, using the choice between resurfacing and not resurfacing the patella in total knee arthroplasty as an example. We used a decision analysis technique based on probability theory and on Bayesian logic, with the help of an especially developed computer software. The process involves building a decision tree, searching for probabilities and utilities in the literature, folding back the tree to compute the baseline result, and running sensitivity analyses. Our literature search provided 26 useful articles, only 3 of which were randomized controlled trials. In the baseline analysis, both options were rated similarly, with resurfacing the patella faring slightly better. Sensitivity analyses revealed that not resurfacing becomes the procedure of choice if the probability of postoperative anterior knee pain with an unresurfaced patella falls below 14%, or if the probability of having pain with a resurfaced patella rises above 8% or if the utility of patellar implant failure falls below 80% of the utility of a perfect health state. Computer-assisted decision analysis is a promising, evidence-based tool to assist clinical decision making in orthopaedic surgery. However, its validity is limited by the poor quality of data found in the orthopaedic literature, especially the scarcity of randomized controlled trials.

Canadian guidelines for economic evaluation of pharmaceuticals. Canadian Collaborative Workshop for Pharmacoeconomics

In 1994, Canada became the second country to release national guidelines for the economic evaluation of pharmaceuticals. The guidelines were developed over a period of 18 months through an elaborate process of broad consultation with a wide variety of relevant stakeholders. The intent of the guidelines is to provide guidance to doers and users of studies, by laying out the general 'state of the art' regarding methods, and by providing specific methodological advice on many matters. The aim is to improve the scientific quality and integrity of studies, and to enhance consistency and comparability across studies. This article presents the Canadian guidelines, both in summary and in detail. Because the techniques of economic evaluation are widely applicable beyond pharmaceuticals, the guidelines will be of interest to researchers and decision makers in all fields of healthcare. Because the methods are not country specific, the guidelines will be of interest to those in other countries as well as in Canada.

The clinically negative neck in patients with early oral cavity carcinoma: a decision-analysis approach to management

Despite improvements in both diagnostic and therapeutic techniques in recent decades, the prognosis for oral cavity squamous cell carcinoma has not improved. Patients presenting with overt regional metastases necessarily undergo therapeutic intervention directed to both the primary site and the neck. However, controversy persists regarding the best management for patients without clinical evidence of nodal disease. Would these patients best be managed with elective treatment of the neck, with no neck treatment unless overt nodal metastases are detected, or would some diagnostic test be beneficial in determining which patients are at highest risk of having occult nodal disease and, therefore, most likely to benefit from elective treatment? We performed a decision analysis to address this question. Baseline probability assumptions were made based on the evidence available in the literature for the parameters of interest. A decision tree was constructed and analyzed. In the final analysis, two options, elective functional neck dissection for all patients and a supraomohyoid neck dissection, were equally beneficial and were significantly better than the remaining options tested. Either of these surgical treatment strategies shifted the survival distribution curve significantly to the right.

A randomized trial of a decisional aid for mental capacity assessments

The objective of this study was to evaluate the clinical utility of a decisional aid for mental capacity assessments which was developed using a group judgment methodology. This was carried out by a randomized, controlled trial. The subjects comprised 64 University of Toronto psychiatry residents in postgraduate years 1 through 4. Residents were randomized to carry out mental capacity assessments on simulated cases with, or without, the use of the decisional aid. The main outcome measure was the extent of agreement between the mental capacity determinations of residents and those of experts. There was no difference between the intervention and control groups with respect to the overall mean level of agreement with experts (0.87 vs 0.86, p = 0.88; 95% confidence interval for the difference between the study groups, -0.07 to +0.08). A logistic regression analysis, which adjusted for imbalances between the groups, also revealed no difference between the groups in their agreement with experts. The mean time per competency assessment was significantly longer in the intervention group (19.1 vs 10.8 min; p < 0.001). It was concluded that the decisional aid did not improve the ability of the psychiatry residents to make mental capacity assessments on simulated cases. Despite relatively limited formal training, the psychiatry residents had a high level of agreement with experts.

Surgical decision analysis: esophagectomy/esophagogastrectomy with or without drainage?

Decision analysis was used to compare three management strategies for patients undergoing esophagogastrectomy for carcinoma of the esophagus or gastric cardia: drain all patients with either pyloromyotomy or pyloroplasty, drain no patient, or perform a test that stratifies patients into high-risk and low-risk groups for development of gastric outlet obstruction and drain the high-risk group. Results indicate that a "drain all" approach is appropriate in clinical settings where the risk of gastric outlet obstruction is greater than 10%, as long as the drainage procedure is 95% effective. If a test were developed to stratify patients, it would have to have a sensitivity of 80% when its specificity was 100%, and would require a higher sensitivity as the specificity fell below 100%.