We developed a comorbidity index on a cohort of 162,699 Medicare beneficiaries who bad an acute myocardial infarction (AMI) in 1987 and validated it on two national cohorts : (1) a cohort of 164,427 Medicare beneficiaries who bad an AMI in 1988 and (2) a cohort of 10,466 patients admitted to Veterans Administration Hospitals (VAH) for AMI in 1988-1991.
The impact of each comorbidity was expressed as : (1) the risk of mortality for those with the comorbidity, (2) the adjustment to the log odds for 2 year mortality and (3) the age-based likelihood of 2 year mortality.
Models were validated by calculating the area under an ROC curve obtained by fitting a logistic regression model to each validation population.
The two year mortality rate for 30-day survivors was approximately 30% in each of the 3 cohorts.
The 5 most prevalent comorbidities coded in the developmental cohort were heart failure (34%), chronic angina (27%), minor arrythmias (25%) and uncomplicated hypertension (18%). Cancer was the most powerful predictor of 2 year mortality, impacting mortality the same as a 18.3 year age increase.
Saturation (having all secondary diagnoses in the discharge summary filled) resulted in a 9.2 year age increase.
Validation in the 1988 Medicare and in the Veterans Administration Hospitals cohorts resulted in areas of 73% and 72% under the respective ROC curves.
Our methods can serve as a prototype for others wishing to assess comorbidity in other targeted subgroups.
Mots-clés Pascal : Infarctus, Myocarde, Aigu, Association morbide, Echelle évaluation, Méthode étude, Modèle mathématique, Pronostic, Vieillard, Homme, Age, Appareil circulatoire pathologie, Cardiopathie coronaire, Myocarde pathologie
Mots-clés Pascal anglais : Infarct, Myocardium, Acute, Concomitant disease, Evaluation scale, Investigation method, Mathematical model, Prognosis, Elderly, Human, Age, Cardiovascular disease, Coronary heart disease, Myocardial disease
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 95-0149206
Code Inist : 002B12A03. Création : 09/06/1995.