Exploring the Association Between Disease-Specific Composite Process Scores and Patient Outcomes in Patients with Acute Myocardial Infarction in Taiwan
Date Issued
2015
Date
2015
Author(s)
Fan, Chieh-Min
Abstract
Background: Composite quality-of-care measures have been increasingly developed and applied for public reporting and pay-for-performance initiative. However, some defects have been noted when composite measures were applied in a clinical setting. First, different methods of computing composite scores can lead to unfair ranking. Second, the relationship between the composite score and other indicators, such as patient outcomes, remains unclear. Objective: We explored the relationship between composite process scores, at the patient and hospital levels, and short-term patient outcomes and compared the differences types of hospital-level composite score. Ultimately, we intended to determine the composite score that most accurately represents the quality of hospital care for patients with acute myocardial infarction (AMI). Methods: All patients who were admitted for AMI (International Classification of Diseases, Ninth Revision, Clinical Modification 410.xx [excluding 410.x2]) for the first time in Taiwan between January 1, 2005 and December 31, 2009 were identified in the National Health Insurance Research Database. Six process indicators (ie, Aspirin usage, Beta-blocker usage, Statin usage, Left ventricle function evaluation, ACEI/ARB usage on left ventricular systolic dysfunction, and Clopidogrel usage on medical treatment) were used to assemble the composite process scores. Three methods for calculating patient-level composite scores (ie, patient average, 70% standard, and all or none) and 4 methods for calculating hospital-level composite scores (ie, overall average, simple weighted average, all or none, and factor analysis) were employed. The outcomes were 30-day mortality after hospitalization and 30-day all-cause readmission after discharge. Multivariate logistic regression was applied to examine the relationship of the patient outcomes to the patient-level composite process measures. A multilevel hierarchical logistic regression model was applied to examine the relationships between the patient outcomes and factors at the two levels. Results: Between January 1, 2006 and September 31, 2009, we identified 31 899 patients with 30-day mortality and 25 119 patients with all-cause readmission. The patients were distributed among 19 medical centers, 71 regional hospitals, and 34 district hospitals. All 3 patient-level composite scores were inversely related to 30-day mortality and all-cause readmission in the multivariate logistic regression. The mean ± standard deviation was calculated for each method for calculating hospital-level composite scores: overall average (0.57 ± 0.17), simple weighted average (0.62 ± 0.16), all or none (0.18 ± 0.15), and factor analysis (0.61 ± 0.17). The 4 hospital-level composite scores of medical centers were significantly higher than those of the regional and district hospitals. The 4 hospital-level composite scores, including both the raw scores and those determined according to hospital rankings, were highly correlated to each other, but using different methods caused the hospitals to be categorized into different categories. In the multilevel analysis, only the hospital-level composite overall average, simple average, and factor analysis scores for the regional hospitals were inversely associated with patient 30-day mortality when the patient-level quality of care was controlled for. The 4 hospital-level composite scores were not correlated to patient 30-day all-cause readmission when the hospital accreditation level or patient-level quality of care were controlled for. Conclusion: Because of value competition among medical services, patient outcomes are a critical factor. All 3 patient-level composite scores can be used to represent patient-level quality of care related to short-term outcomes for patients with AMI. 70% standard is not inferior to all-or-none in patient-level. The hospital-level composite scores were related to patient outcomes only under certain conditions, and using different composite scoring methods might lead to different rankings. Selecting methods for public reporting or pay-for-performance initiatives for patients with AMI should be considered carefully. Further research on developing new hospital-level composite quality scoring is warranted.
Subjects
Composite score
Acute myocardial infarction (AMI)
30-day mortality
30-day readmission
Multilevel analysis
Type
thesis
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