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¿Influye la inclusión de literatura gris en las estimaciones de la efectividad de la intervención reportadas en los
1Thomas C Chalmers Center for Systematic Reviews, Children's Hospital of Eastern Ontario Research Institute, Ottawa, Canada.
Lancet (London, England)
|November 10, 2000
Resumen
Excluir la literatura gris de los metanálisis puede inflar las estimaciones de la efectividad de la intervención. Incluir toda la evidencia disponible, tanto la literatura publicada como la literatura gris, es crucial para revisiones sistemáticas y metaanálisis precisos.
Área de la Ciencia:
- Metodología de la investigación médica metodología de la investigación médica.
- La medicina basada en la evidencia es la medicina basada en la evidencia.
- La bioestadística es la bioestadística.
Sus antecedentes:
- Los metanálisis pueden ser sesgados si excluyen la evidencia disponible, particularmente la literatura gris.
- La literatura gris, o estudios no publicados, pueden diferir sistemáticamente de los estudios publicados.
- Este estudio investiga el impacto de incluir o excluir la literatura gris en los resultados del metanálisis.
Objetivo del estudio:
- Determinar si la exclusión de la literatura gris de los metanálisis conduce a diferentes estimaciones de efectividad en comparación con su inclusión.
- Cuantificar el sesgo potencial introducido por la omisión de estudios no publicados.
Principales métodos:
- Se examinó una muestra aleatoria de 135 metanálisis.
- Se seleccionaron 33 metaanálisis que incluían literatura publicada y literatura gris para un análisis detallado.
- Se utilizó la regresión logística para explorar el efecto de la inclusión de literatura gris en los resultados cuantitativos.
Principales resultados:
- El 33% de los metanálisis incorporó alguna literatura gris.
- La literatura gris constituía entre el 4,5% y el 75% de los estudios dentro de los metanálisis.
- La exclusión de la literatura gris dio como resultado una sobreestimación del 15% de los efectos de la intervención (OR = 1.15), aumentando aún más al 33% cuando se excluyeron los resúmenes (OR = 1.33).
Conclusiones:
- La exclusión de la literatura gris de los metanálisis puede conducir a estimaciones exageradas de la efectividad de la intervención.
- Los metaanalistas deben esforzarse por incluir toda la evidencia relevante, que abarca tanto la literatura publicada como la literatura gris.
- La búsqueda exhaustiva de evidencia es esencial para los hallazgos válidos y confiables del metanálisis.
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