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Does simplicity compromise accuracy in ACS risk prediction? A retrospective analysis of the TIMI and GRACE risk scores.
PLoS One. 2009 Nov 23; 4(11):e7947.Plos

Abstract

BACKGROUND

The Thrombolysis in Myocardial Infarction (TIMI) risk scores for Unstable Angina/Non-ST-elevation myocardial infarction (UA/NSTEMI) and ST-elevation myocardial infarction (STEMI) and the Global Registry of Acute Coronary Events (GRACE) risk scores for in-hospital and 6-month mortality are established tools for assessing risk in Acute Coronary Syndrome (ACS) patients. The objective of our study was to compare the discriminative abilities of the TIMI and GRACE risk scores in a broad-spectrum, unselected ACS population and to assess the relative contributions of model simplicity and model composition to any observed differences between the two scoring systems.

METHODOLOGY/PRINCIPAL FINDINGS

ACS patients admitted to the University of Michigan between 1999 and 2005 were divided into UA/NSTEMI (n = 2753) and STEMI (n = 698) subpopulations. The predictive abilities of the TIMI and GRACE scores for in-hospital and 6-month mortality were assessed by calibration and discrimination. There were 137 in-hospital deaths (4%), and among the survivors, 234 (7.4%) died by 6 months post-discharge. In the UA/NSTEMI population, the GRACE risk scores demonstrated better discrimination than the TIMI UA/NSTEMI score for in-hospital (C = 0.85, 95% CI: 0.81-0.89, versus 0.54, 95% CI: 0.48-0.60; p<0.01) and 6-month (C = 0.79, 95% CI: 0.76-0.83, versus 0.56, 95% CI: 0.52-0.60; p<0.01) mortality. Among STEMI patients, the GRACE and TIMI STEMI scores demonstrated comparably excellent discrimination for in-hospital (C = 0.84, 95% CI: 0.78-0.90 versus 0.83, 95% CI: 0.78-0.89; p = 0.83) and 6-month (C = 0.72, 95% CI: 0.63-0.81, versus 0.71, 95% CI: 0.64-0.79; p = 0.79) mortality. An analysis of refitted multivariate models demonstrated a marked improvement in the discriminative power of the TIMI UA/NSTEMI model with the incorporation of heart failure and hemodynamic variables. Study limitations included unaccounted for confounders inherent to observational, single institution studies with moderate sample sizes.

CONCLUSIONS/SIGNIFICANCE

The GRACE scores provided superior discrimination as compared with the TIMI UA/NSTEMI score in predicting in-hospital and 6-month mortality in UA/NSTEMI patients, although the GRACE and TIMI STEMI scores performed equally well in STEMI patients. The observed discriminative deficit of the TIMI UA/NSTEMI score likely results from the omission of key risk factors rather than from the relative simplicity of the scoring system.

Authors+Show Affiliations

Division of Cardiovascular Medicine, University of Michigan, Ann Arbor, Michigan, United States of America.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

19956773

Citation

Aragam, Krishna G., et al. "Does Simplicity Compromise Accuracy in ACS Risk Prediction? a Retrospective Analysis of the TIMI and GRACE Risk Scores." PloS One, vol. 4, no. 11, 2009, pp. e7947.
Aragam KG, Tamhane UU, Kline-Rogers E, et al. Does simplicity compromise accuracy in ACS risk prediction? A retrospective analysis of the TIMI and GRACE risk scores. PLoS One. 2009;4(11):e7947.
Aragam, K. G., Tamhane, U. U., Kline-Rogers, E., Li, J., Fox, K. A., Goodman, S. G., Eagle, K. A., & Gurm, H. S. (2009). Does simplicity compromise accuracy in ACS risk prediction? A retrospective analysis of the TIMI and GRACE risk scores. PloS One, 4(11), e7947. https://doi.org/10.1371/journal.pone.0007947
Aragam KG, et al. Does Simplicity Compromise Accuracy in ACS Risk Prediction? a Retrospective Analysis of the TIMI and GRACE Risk Scores. PLoS One. 2009 Nov 23;4(11):e7947. PubMed PMID: 19956773.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Does simplicity compromise accuracy in ACS risk prediction? A retrospective analysis of the TIMI and GRACE risk scores. AU - Aragam,Krishna G, AU - Tamhane,Umesh U, AU - Kline-Rogers,Eva, AU - Li,Jin, AU - Fox,Keith A A, AU - Goodman,Shaun G, AU - Eagle,Kim A, AU - Gurm,Hitinder S, Y1 - 2009/11/23/ PY - 2009/09/08/received PY - 2009/10/27/accepted PY - 2009/12/4/entrez PY - 2009/12/4/pubmed PY - 2010/4/27/medline SP - e7947 EP - e7947 JF - PloS one JO - PLoS One VL - 4 IS - 11 N2 - BACKGROUND: The Thrombolysis in Myocardial Infarction (TIMI) risk scores for Unstable Angina/Non-ST-elevation myocardial infarction (UA/NSTEMI) and ST-elevation myocardial infarction (STEMI) and the Global Registry of Acute Coronary Events (GRACE) risk scores for in-hospital and 6-month mortality are established tools for assessing risk in Acute Coronary Syndrome (ACS) patients. The objective of our study was to compare the discriminative abilities of the TIMI and GRACE risk scores in a broad-spectrum, unselected ACS population and to assess the relative contributions of model simplicity and model composition to any observed differences between the two scoring systems. METHODOLOGY/PRINCIPAL FINDINGS: ACS patients admitted to the University of Michigan between 1999 and 2005 were divided into UA/NSTEMI (n = 2753) and STEMI (n = 698) subpopulations. The predictive abilities of the TIMI and GRACE scores for in-hospital and 6-month mortality were assessed by calibration and discrimination. There were 137 in-hospital deaths (4%), and among the survivors, 234 (7.4%) died by 6 months post-discharge. In the UA/NSTEMI population, the GRACE risk scores demonstrated better discrimination than the TIMI UA/NSTEMI score for in-hospital (C = 0.85, 95% CI: 0.81-0.89, versus 0.54, 95% CI: 0.48-0.60; p<0.01) and 6-month (C = 0.79, 95% CI: 0.76-0.83, versus 0.56, 95% CI: 0.52-0.60; p<0.01) mortality. Among STEMI patients, the GRACE and TIMI STEMI scores demonstrated comparably excellent discrimination for in-hospital (C = 0.84, 95% CI: 0.78-0.90 versus 0.83, 95% CI: 0.78-0.89; p = 0.83) and 6-month (C = 0.72, 95% CI: 0.63-0.81, versus 0.71, 95% CI: 0.64-0.79; p = 0.79) mortality. An analysis of refitted multivariate models demonstrated a marked improvement in the discriminative power of the TIMI UA/NSTEMI model with the incorporation of heart failure and hemodynamic variables. Study limitations included unaccounted for confounders inherent to observational, single institution studies with moderate sample sizes. CONCLUSIONS/SIGNIFICANCE: The GRACE scores provided superior discrimination as compared with the TIMI UA/NSTEMI score in predicting in-hospital and 6-month mortality in UA/NSTEMI patients, although the GRACE and TIMI STEMI scores performed equally well in STEMI patients. The observed discriminative deficit of the TIMI UA/NSTEMI score likely results from the omission of key risk factors rather than from the relative simplicity of the scoring system. SN - 1932-6203 UR - https://www.unboundmedicine.com/medline/citation/19956773/Does_simplicity_compromise_accuracy_in_ACS_risk_prediction_A_retrospective_analysis_of_the_TIMI_and_GRACE_risk_scores_ L2 - https://dx.plos.org/10.1371/journal.pone.0007947 DB - PRIME DP - Unbound Medicine ER -