Tuesday, March 12, 2013

What Reading that Give Dieters Money to Lose Weight Article Actually Told Me

Wow did this paper get more press than it deserved, and it's not even a paper!

For background, if you haven't heard people are tweeting and posting links to a story that suggests, "Cash Can Coax Dieters to Lose Weight" while that same story has made headlines the world over.

Not one to post links to abstracts or press releases without reading the paper, but intrigued by the attention, I set out to find the paper and read the study.

So what'd I learn from the read?

Firstly that there's actually nothing to read. There is no published study. Here we're talking about an abstract that was presented 3 days ago at a cardiology conference.

Secondly I learned that regardless of the fact that the folks who were paid cash did better, "better" meant losing 9.1lbs in a year vs. 2.3lbs, and a dropout rate of 38% vs. 74%. Now the dropout rate in the cash group is pretty typical for a behavioural weight loss intervention, perhaps ever so slightly better than average even, but certainly nothing to write home about if the suggestion is that cash helps with adherence. And what's there to be made from the staggering 74% dropout rate in the control group that received the same freely provided intervention? My take is that the intervention they used must be truly awful as how bad does your freely provided weight loss intervention have to be to yield a drop out rate of 74%?

And what of the losses? 9.1lbs? Considering the press release reports the participants' average BMIs ranged between 30 and 40, the 9.1lb intention to treat loss to me sounds like pretty much what you would expect in a well designed behavioural weight management program without cash incentives, while the 2.3lb loss is lower than would be expected of a well designed program.

Lastly I learned that the abstract's presenter/author disclosed a financial relationship with a company called GymPact which as you might guess, uses financial incentives and disincentives in encouraging people to exercise.

The one thing I didn't learn is anything about long-term outcomes. I'd argue that especially with an intervention like monetary incentivization we need the long-term data as I'd bet that for many the money involved might lead them to "try harder" which while you might think that'd be a good thing, my experience has taught me the opposite. Whereby if the money led a person to be all the more strict with their lifestyle changes they'd be far less likely to sustain that degree of strictness when the incentive to do so disappeared.

I can't fathom why this abstract made headlines. The weight loss was minimal. The drop out rate abysmal. The study too short. And it's just an abstract! One thing however is certain - the fact that this abstract with really lame outcomes captured the world's attention is a truly terrifying statement as to what passes for news these days when it comes to obesity.