A logistic regression model when some events precede treatment: the effect of thrombolytic therapy for acute myocardial infarction on the risk of cardiac arrest.
J Clin Epidemiol
; 50(11): 1219-29, 1997 Nov.
Article
em En
| MEDLINE
| ID: mdl-9393378
ABSTRACT
When outcomes occur in clinical trials before treatment can be given, neither intent-to-treat nor according-to-protocol analyses give optimal estimates of the treatment effect. A better approach employs a time-dependent variable for treatment. Intent-to-treat analyses are conservative, biasing against treatment; according-to-protocol analyses bias in favor of treatment. We show how to measure the effect of a time-dependent variable in a logistic regression using person-time intervals as units of measurement and describe appropriate methods for reporting model performance. The method is applied to develop a model to predict the probability that a patient with a myocardial infarction will have a sudden cardiac arrest within 48 hours of presentation to emergency medical services both when treated with thrombolysis and when not treated. We use a time-dependent treatment variable because many patients went into cardiac arrest while awaiting treatment. This technique has been programmed into an electrocardiograph for real-time use in an emergency department.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Terapia Trombolítica
/
Parada Cardíaca
/
Infarto do Miocárdio
Tipo de estudo:
Diagnostic_studies
/
Etiology_studies
/
Guideline
/
Prognostic_studies
/
Risk_factors_studies
Limite:
Aged
/
Humans
/
Middle aged
Idioma:
En
Revista:
J Clin Epidemiol
Assunto da revista:
EPIDEMIOLOGIA
Ano de publicação:
1997
Tipo de documento:
Article
País de afiliação:
Estados Unidos