This edition of talk evidence was recorded before the big increase in covid-19 infections in the UK, and then delayed by some self isolation. We'll be back with more evidence on the pandemic very soon.

As always Duncan Jarvies is joined by Helen Macdonald (resting GP and editor at The BMJ) and Carl Heneghan (active GP, director of Oxford University’s CEBM and editor of BMJ Evidence).

in this episode

(1.01) Helen talks about variation in prescription of opioids - do 1% of clinician really prescribe the vast majority of the drug?

(8.45) Carl tells us that its time papers (in this case a lung screening one) really present absolute numbers.

(17.30) Carl explains how a spoonfull (less) of salt helps the blood pressure go down

(21.25) Helen puts test results under a microscope, and finds out that they may vary.

(33.20) What do conflicts of interest in tanning papers mean for wider science?

(48.05) Carl has a "super-rant" about smartphone apps for skin cancer - and a sensitivity of 0.

Reading list:

Opioid prescribing patterns among medical providers in the United States, 2003-17: retrospective, observational study

https://www.bmj.com/content/368/bmj.l6968

Reduced Lung-Cancer Mortality with Volume CT Screening in a Randomized Trial

https://www.nejm.org/doi/full/10.1056/NEJMoa1911793

Effect of dose and duration of reduction in dietary sodium on blood pressure levels

https://www.bmj.com/content/368/bmj.m315

Your results may vary: the imprecision of medical measurements

https://www.bmj.com/content/368/bmj.m149

Association between financial links to indoor tanning industry and conclusions of published studies on indoor tanning: systematic review

https://www.bmj.com/content/368/bmj.m7

Algorithm based smartphone apps to assess risk of skin cancer in adults: systematic review of diagnostic accuracy studies