Friday, February 25, 2022

Very Brief Blog: Vinay Prasad's Two Articles on the Parachute Metaphor

We've all heard the parachute metaphor (you don't do RCTs to learn the value of parachutes).   The classic source is Smith and Pell, 2003 BMJ here.  That article will soon celebrate its 20th anniversary.  Many later authors have joined the theme;  e.g. Yeh BMJ 2018 - here.

There are two Vinay Prasad articles on the topic.

For the most recent, see:

The use and meaning of the parachute metaphor in biomedicine: a citation analysis of a systematic review and a randomized trial of the parachute for freefall (2022)

Find this online here ($70; Xu and Prasad) and his current Twitter discussion here.

But there's also a 2018 open access article coauthored by Prasad on the same theme in CMAJ Open:

Most medical practices are not parachutes: a citation analysis of practices felt by biomedical authors to be analogous to parachutes (2018)

Find this here (Open; Hayes, Kaestner, Mailankody, Prasad) and 2020 Twitter here.

The $70 article: Is it worthwhile?   I used the US value of $100,000 per QALY.  That is, if reading the article (or not reading it) was worth a life-year, I'd be willing to pay $100,000 (or alternatively, trade a life-year) to read the article.  $70 is 1/1428th of $100,000.   Therefore, based on its $70 price, the article should be worth 1/1428th of a QALY life-year, or about 1/4 day, or 6 hours.  

Unsplash, Kamil Pietrrzak. Sienna Wall