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#RCTinaTweet

November 4, 2015

Doing it in 140 characters

The PICO method of summarising randomised controlled trials – Population studied, Intervention and Control group treatments, and primary Outcome – is good, but we often need to know more. Has the question already been answered, has it been judged important by patients and stakeholders, and is the trial large enough to have a reasonable chance of answering it reliably? Some protocols take many pages to tell us all that, some a side of A4, and a few fit it in to a 500 word abstract. Can anyone do it in 140 characters? Here’s two attempts.

PITCHES trial. Protocol here PITCHES CTIMP protocol V2 2 19_07_15 (4)

Here’s the tweet

JLA5preterm, P f obs cholest, I300UDCA, C300placebo, O perinat death morbid, α.05, β.2, ER.05, RR.5

Total 129 characters because twitter contracts the hyperlink to 23; Seventeen to spare. The trial was funded before the James Lind Alliance completed its top ten list of research priorities for preterm labour, so the question has not actually been ranked. My made-up ranking of 5th in the preterm labour JLA list took 11 characters. The evidence is summarised in the hyperlinked Cochrane review. The population is [pregnant] females with obstetric cholestasis, the intervention group get a drug called ursodeoxycholic acid, and the control group placebo. There will be 300 women in each group. The primary outcome is a composite of baby death in the perinatal period or morbidity [severity undefined]. Assuming that we are willing to accept a 5% chance of getting a positive result when really there is no difference (alpha = 0.05) the trial has 80% power (beta = 0.2) of showing a difference, if the rate of death or morbidity is 5% (event rate 0.05) and the treatment (UDCA) really halves the risk of death or morbidity by 50% (a relative risk of 0.5). Cool eh?

35-39 trial. Protocol here

Here’s the tweet

JLA9stillbirth, P preg f>35yrs, I315 IOL39w, C315 wait T+7-14, O Caesar, α.05, β.2, ER.3, RR.68

Hyperlink contracted to 23 again, making total 119, with 21 to spare. Again the 35-39 trial was funded before the James Lind Alliance completed its top ten list of research priorities for stillbirth prevention, so the 14 characters of “JLA9stillbirth” describe a fictional ranking. The hyperlink is to the relevant Cochrane review. The population is pregnant women aged over 35, the intervention group are offered labour induction at 39 weeks and the control group to wait until the usual time of term plus 7-14 days. 315 participants will be recruited to each group. The primary outcome is Caesarean section. With a 5% chance of getting a positive result when really there is no difference (alpha = 0.05) the trial has 80% power (beta = 0.2) of showing a difference, if the control Caesarean event rate (ER) is 30% (event rate 0.3) and induction really reduces this by one third (a relative risk of 0.67).

My suggested hashtag #RCTinatweet is only 12 characters so could be added to both.  I really need to get out more!

Jim Thornton

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