Showing papers by "Roger A. Horn published in 1986"
TL;DR: The conclusion is that the Severity of Illness Index is a reliable and valid tool for measuring inpatient severity of illness.
Abstract: The authors discuss the objectives and definition of the Severity of Illness Index, which has been developed and refined at The Johns Hopkins University over the past 5 years. In addition, the training program for raters, the method used to ascertain reliability, and data from reliability testing in
109 citations
TL;DR: The new Computerized Severity Index (CSI) that is obtained from an expanded discharge abstract data set, based on a 6th-digit severity addition to the ICD-9-CM coding system is described.
Abstract: We describe the new Computerized Severity Index (CSI) that is obtained from an expanded discharge abstract data set, based on a 6th-digit severity addition to the ICD-9-CM coding system. The new 6-digit code book (called ICD-9-CMSA) is used to label existence and severity of each principal and secondary diagnosis. It can be used to produce an overall severity of illness level for each hospital inpatient. The impact of severity-adjusted DRGs on prospective payment and uses of the CSI for assessing quality of care, efficiency, physician practice profiles, and prediction of posthospital resource needs are discussed.
56 citations
TL;DR: The findings indicate that the phenomenon of severity of illness differences within DRGs, and the corresponding differences in resource use, is consistent across 15 hospitals that represent all sections of the United States and all teaching types.
Abstract: The authors assess the ability of the Severity of Illness Index to explain variability of resource use within each DRG. The data came from 15 hospitals, all of which had a HCFA DRG case mix index greater than 1. The data set comprised approximately 106,000 discharges, for which discharge abstract da
54 citations
TL;DR: In this article, the authors give necessary and sufficient conditions for the existence of a unitary S which reduces both A 1 and A 2 to diagonal form in this way, when at least one of A 1 or A 2 is nonsingular.
23 citations
TL;DR: The findings that 37 per cent of the physicians in the study may be wrongly identified as over- or under-utilizers suggest long-term public health consequences of preparing physician profiles based on unadjusted DRGs.
Abstract: We report on a study that examined physician practice profiles using two methods of patient classification: the Severity of Illness Index and diagnosis-related groups (DRGs). When used together with conventional management information and DRGs, the Severity of Illness Index permitted useful comparisons to be made among physicians; differences in both case-mix and severity could be estimated. In 37 per cent of the physicians studied, we found differences of more than $10,000 in the apparent impact of a physician on the hospital's financial position, depending on whether one controlled for severity or not. The extent to which these differences in impact could be due to quality of care differences is an area for future research. However, the findings that 37 per cent of the physicians in the study may be wrongly identified as over- or under-utilizers suggest long-term public health consequences of preparing physician profiles based on unadjusted DRGs.
19 citations
TL;DR: Examination of discharge-abstract data from 14 cystic fibrosis centers in a comparison of resource-use requirements by patients with cystic Fibrosis and other patients in the same diagnosis-related group found the ratio between the costs and the lengths of stay was greater than the ratio for the two groups, reflecting the more intense use of resources by the patients.
Abstract: Under the Medicare prospective payment system, which is based on diagnosis-related groups, patients with certain diseases may be inappropriately classified. To study this problem using cys...
17 citations
TL;DR: In this article, the problem of reducing a given n-by-n complex matrix A to triangular or diagonal form by a transformation of the form $A \to SA\bar S^{ - 1} $, where S is a nonsingular n- by n complex matrix, was studied.
Abstract: We study the problem of reducing a given n-by-n complex matrix A to triangular or diagonal form by a transformation of the form $A \to SA\bar S^{ - 1} $, where S is a nonsingular n-by-n complex matrix. We also consider the special case of this reduction in which S is unitary, and a generalization to the problem of simultaneously reducing a family of matrices in this way. Natural analogues of eigenvalues and eigenvectors arise in this context; they have both familiar and unfamiliar properties.
10 citations