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A representation and interpretation of the area under a receiver operating characteristic (ROC) curve obtained by the "rating" method, or by mathematical predictions based on patient characteristics, is presented. It is shown that in such a setting the area represents the probability that a randomly chosen diseased subject is (correctly) rated or ranked(More)
Receiver operating characteristic (ROC) curves are used to describe and compare the performance of diagnostic technology and diagnostic algorithms. This paper refines the statistical comparison of the areas under two ROC curves derived from the same set of patients by taking into account the correlation between the areas that is induced by the paired nature(More)
OBJECTIVE To determine the effect of more intensive treatments on mortality in elderly patients with acute myocardial infarction (AMI). DESIGN Analysis of incremental treatment effects using differential distances as instrumental variables to account for unobserved case-mix variation (selection bias) in observational Medicare claims data (1987 through(More)
In this review of the theoretical and empirical work on patient satisfaction with care, the most consistent finding is that the characteristics of providers or organizations that result in more "personal" care are associated with higher levels of satisfaction. Some studies suggest that more personal care will result in better communication and more patient(More)
We determined whether adherence to recommendations for coronary angiography more than 12 h after symptom onset but prior to hospital discharge after acute myocardial infarction (AMI) resulted in better survival. Using propensity scores, we created a matched retrospective sample of 19,568 Medicare patients hospitalized with AMI during 1994-1995 in the United(More)
The data for medical decision analyses are often unreliable. Traditional sensitivity analysis--varying one or more probability or utility estimates from baseline values to see if the optimal strategy changes--is cumbersome if more than two values are allowed to vary concurrently. This paper describes a practical method for probabilistic sensitivity(More)
We investigated how variations in the way information is presented to patients influence their choices between alternative therapies. Data were presented summarizing the results of surgery and radiation therapy for lung cancer to 238 ambulatory patients with different chronic medical conditions and to 491 graduate students and 424 physicians. We asked the(More)
BACKGROUND There are large geographic differences in the frequency with which coronary angiography and revascularization are performed. We attempted to assess whether differences in case mix or in the treatment of specific groups of patients may explain this variability. We also assessed the consequences of various patterns of treatment. METHODS We(More)
The value of a diagnostic test lies in its ability to detect patients with disease (its sensitivity) and to exclude patients without disease (its specificity). For tests with binary outcomes, these measures are fixed. For tests with a continuous scale of values, various cutoff points can be selected to adjust the sensitivity and specificity of the test to(More)
The accuracies of magnetic resonance (MR) imaging and computed tomography (CT) in determining tumor classification and assessing mediastinal node metastases were compared in a prospective cooperative study of 170 patients with non-small cell bronchogenic carcinoma. The sensitivity of CT in distinguishing T3-T4 tumors from T0-T2 tumors was 63%; specificity(More)