Inadvertent P‐hacking among trials and systematic reviews of the effect of progestogens in pregnancy? A systematic review and meta‐analysis

Progestogens have been evaluated in numerous trials and meta‐analyses, many of which concluded they were effective. However, two large trials PROMISE and OPPTIMUM have recently concluded that progesterone was ineffective. This raises the possibility that earlier studies and reviews had been biased by either selective publication or selective choice of outcomes, so called “P‐hacking”.

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