MPH Master pieces

Cervical cancer control

It is always good to have one's assumptions challenged. We assume that prevention is better than cure. But prevention may take a long time, and people are dying now.

This interesting paper argues that our focus on HPV vaccine to control cervical cancer may, at least in poorer countries, be wrong. It may be better to put the effort into screening, not with Pap smears but with VIA - visual inspection with acetic acid. VIA is a 'see and treat' technique - no need to return to the clinic for a second visit after the screen result is known. This has huge advantages in many communities.

Vaccines are propelled by commercial forces, but VIA isn't.

Weight watchers works

How to lose weight? This trial compares Weight Watchers (12 months free membership) with 'usual care' in slightly obese adults (BMI 27 - 35). Design and execution of the trial look good. Weight loss was modest (5kg) and dropout rates high, which is typical of weight loss programmes.

Kate Jolly and Paul Aveyard have written a good commentary. I'd add two further observations:

1. the comparator was 'usual care' but this was a multinational trial. 'Usual' in the UK is not the same as 'usual' in Germany whihc is not the same as 'usual' in Australia.

2. the trial was funded by Weight Watchers 'via a grant to the MRC'. That's probably ok but what would we have said if this was a drug trial funded by the company that made the drug?

 

 

Response bias

People lie (aka social desirability bias). Here's a nifty solution.

Validating a fitness questionnaire

Don't worry too much about the detail, but here's a nice illustration of the effort needed to prove that a simple questionnaire is valid (does what it says in the title) and reliable (gives the same answer each time). Here is the questionnaire; here is the validation and reliability study.

Peanuts

I seem to be posting a series of communicable disease items. Here is a readable account of a large outbreak in the USA. The outbreak strain was isolated from the suspect foodstuff - that's quite unusual (and maybe it's what made this story publishable). Often, by the time a particular foodstuff is suspected it has all been eaten or destroyed.