Need to test theories

Advice, apparently rational in theory...Some treatments are in use for a long time before it is realized that they can do more harm than good.

Need to test the validity of theories in practice

Advice on babies’ sleeping position

Dr Spock’s bestselling book contained harmful advice on babies’ sleeping position

Based on untested theory, Benjamin Spock, the influential American child health expert, informed the readers of his bestselling book ‘Baby and Child Care’ that a disadvantage of babies sleeping on their backs was that, if they vomited, they would be more likely to choke. Dr Spock therefore advised his millions of readers to encourage babies to sleep on their tummies.

https://en.testingtreatments.org/book/2-hoped-for-effects-that-dont-materialize/advice-on-babies-sleeping-position/

With seemingly irrefutable logic – and certainly a degree of authority – from the 1956 edition of Dr Benjamin Spock book until the late 1970s he argued

Advice on babies’ sleeping position

INFO

First recommendations of the American Academy of Pediatrics

There is evidence of damageee

"Advice to put infants to sleep on the front for nearly a half century was contrary to evidence available from 1970 that this was likely to be harmful..."

Gilbert systematic review

INFO

Recommended infant sleeping position in books on infant care

Gilbert systematic review

"Systematic review of preventable risk factors for SIDS from 1970 would have led to earlier recognition of the risks of sleeping on the front and might have prevented over 10 000 infant deaths in the UK and at least 50 000 in Europe, the USA, and Australasia....This phenomenon is likely to be a general problem in the use of observational studies for assessing the safety of health promotion".

Gilbert systematic review

HRT was so heavily promoted specifically as a way of reducing heart attacks and stroke.

For over 20 years millions of women began using HRT for longer

In women going through the menopause, hormone replacement therapy (HRT) is very effective in reducing hot flushes, prevent osteoporosis, prevention of heart attacks and stroke.

Hormone Replacement Therapy (HRT)

• Now know that HRT increases the risk of stroke and of developing breast cancer.

But the advice is wrong:

• In 1997 Researchers from Finland and the UK reviewed, systematically, the results of well-conducted studies. They found that, far from reducing heart disease, HRT might actually increase it.

Even if patients do not suffer from inadequately tested treatments, using them can waste individual and community resources

Just because a treatment is ‘established’ does not mean it does more good than harm

Neither theory nor professional opinion is a reliable guide to safe, effective treatments

Key points

• Evans I, Thornton H, Chalmers I and Glasziou P (2011). Testing Treatments, 2nd Edition; London: Pinter and Martin. Available: https://en.testingtreatments.org/book/2-hoped-for-effects-that-dont-materialize/

• Why treatment uncertainties should be addressed. In: Clarke M, Atkinson P, Badenoch D, Chalmers I, Glasziou P, Podolsky S, Tröhler U. The James Lind Library´s Introduction to fair test of treatments. Available: http://www.jameslindlibrary.org/essays/1-1-why-treatment-uncertainties-should-be-addressed/

In more depth