Thread by @Luis_I_Gomez

Caramba, caramba. Recuerdan que siempre les digo que debemos ser muy cuidadosos con las asignaciones de causalidad surgidas de estudios epidemiológicos? Y que en el caso de la contaminación del aire aún más cuidadosos?
Les cuento ->

En las últimas semanas se han publicado dos papers muy interesantes al respecto. En ambos participa Stanley Young, quien trabajó muchos años como experto en el National Institute of Statistical Sciences de los EEUU.
niss.org/people/s-stanl…
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En el primer trabajo, "Evaluation of a meta-analysis of air quality and heart attacks, a case study" discute la validez de la asignación entre calidad del aire e infarto cardíaco. Nos dicen:

"A highly cited meta-analysis paper examining whether short-term air quality exposure triggers myocardial infarction was evaluated as a case study." Se refiere a:
"Main air pollutants and myocardial infarction: a systematic review and meta-analysis." ncbi.nlm.nih.gov/pubmed/22337682

Y encuentran que:
"Results suggest the appearance of heterogeneous, researcher-generated p-values used in the meta-analysis rather than unbiased evidence of real effects for air quality"

Lo que les permite concluir:
" We conclude that this meta-analysis does not provide reliable evidence for an association of air quality components with myocardial risk."

Lean el paper entero: junkscience.com/wp-content/upl…
cortesía de @JunkScience
Sigo ->

@JunkScience En el segundo trabajo, "The reliability of an environmental epidemiology meta-analysis, a case study" Young y colegas revisan 14 estudios epidemiológicos sobre el tema. ->

@JunkScience Y nos cuentan: "Claims made in science papers are coming under increased scrutiny with many claims failing to replicate. Meta-analysis studies that use unreliable observational studies should be in question. " ->

@JunkScience "We examine the reliability of the base studies used in an air quality/heart attack meta-analysis and the resulting meta-analysis."

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@JunkScience Metodología: A meta-analysis study that includes 14 observational air quality/heart attack studies is examined for its statistical reliability. ->

@JunkScience We use simple counting to evaluate the reliability of the base papers and a p-value plot of the p-values from the base studies to examine study heterogeneity.

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@JunkScience y qué encuentran?: We find that the based papers have massive multiple testing and multiple modeling with no statistical adjustments. (Sigue) ->

@JunkScience Statistics coming from the base papers are not guaranteed to be unbiased, a requirement for a valid meta-analysis. There is study heterogeneity for the base papers with strong evidence for so called p-hacking.

Interesante.
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@JunkScience La valoración de los autores: We make two observations: there are many claims at issue in each of the 14 base studies so uncorrected multiple testing is a serious issue. We find the base papers and the resulting meta-analysis are unreliable.
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@JunkScience Pueden acceder al paper aquí:

The reliability of an environmental epidemiology meta-analysis, a case study arxiv.org/abs/1902.00770

Espero que estas informaciones les sean de utilidad. Feliz viernes! Y menos pánico alarmista!