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Evaluación empírica de efectos de tratamiento muy grandes de las intervenciones médicas
Tiago V Pereira1, Ralph I Horwitz, John P A Ioannidis
1Health Technology Assessment Unit, Institute of Education and Sciences, German Hospital Oswaldo Cruz, Sao Paulo, Brazil.
JAMA
|October 25, 2012
Resumen
La mayoría de los grandes efectos del tratamiento en la medicina se originan en pequeños estudios y disminuyen con ensayos adicionales. Los efectos grandes bien validados son raros y por lo general implican resultados no fatales.
Área de la Ciencia:
- La investigación médica es la investigación médica.
- Análisis de ensayos clínicos análisis de ensayos clínicos.
- La medicina basada en la evidencia es la medicina basada en la evidencia.
Sus antecedentes:
- La mayoría de las intervenciones médicas producen efectos modestos.
- Ocasionalmente, los ensayos clínicos reportan beneficios o daños sustanciales.
Objetivo del estudio:
- Determinar la frecuencia y las características de los efectos muy grandes del tratamiento en medicina.
- Para analizar cómo estos efectos cambian con la investigación posterior.
Principales métodos:
- Análisis de 85.002 parcelas forestales de la base de datos Cochrane de revisiones sistemáticas (2010).
- Categoría de ensayos basados en efectos estadísticamente significativos muy grandes (odds ratio ≥5) en la primera o posteriores publicaciones.
- Evaluación en profundidad de 250 temas muestreados aleatoriamente de cada categoría.
Principales resultados:
- El 9,7% de los primeros ensayos y el 6,1% de los ensayos posteriores mostraron efectos significativos muy grandes.
- Los efectos muy grandes fueron más comunes en los resultados de eficacia definidos en laboratorio que en la mortalidad.
- En los metanálisis, los tamaños de los efectos generalmente disminuyeron significativamente; 90-98% se volvieron más pequeños.
Conclusiones:
- Los efectos muy grandes del tratamiento a menudo provienen de estudios pequeños y tienden a disminuir con más investigación.
- Los efectos grandes confirmados son poco frecuentes y predominantemente asociados con resultados no fatales.
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