Looking a (small) gift-horse in the mouth

I came across an interesting article by Dana and Loewenstein (2003) that i vaguely heard of once before about the influence of small pharmaceutical gifts on doctors' decisions.

The basic questions are:
1) do gifts influence doctors' beliefs/prescribing habits, and
2) is this a function of gift size

Both doctors and regulating bodies must think that 1) and 2) are true, since the recent guidelines of Pharmaceutical Research and Manufacturers of America define gifts of "more than nominal value" as inappropriate. And surveys show that physicians view small gifts as ethically more acceptable than large gifts, and they don't think that small gifts tempting enough to influence physicians' prescription choices.

Pharmaceutical companies also believe 1) is true, but many restrict their own employees from accepting even small gifts. => big pharma knows something we don't.

Thus policies that restrict gift sizes will be useless if biases introduced by gifts are not related to the size of the gift.

Here's the scenario:
-Pharmaceutical companies employ representatives who meet with physicians with apparent success to aggressively promote newer and typically more expensive drugs
-a study of 29 empirical articles showed that physician interactions with pharmaceutical companies led to increased prescription costs and nonrational prescribing
-all this is questionable, because from 1989 to 2000, the US Food and Drug Administration judged 76% of all approved new drugs to be no more than moderate innovations over existing treatments, with many being a modification to an older product with the same ingredient. In 2000, the average price of these standard-rated new drugs was nearly twice the average price of existing drugs prescribed for the same indications.

some outcomes

• - one retrospective study24 tracked house staff who attended a grand rounds given by a pharmaceutical company speaker and found them more likely to indicate that company's drug as a treatment than did their colleagues. However, many of the house staff did not recall what company sponsored the grand rounds (this reminds me of the Overcoming Bias blog)

• -a positive correlation has been found between the cost of physicians' treatment choices and their amount of interaction with pharmaceutical company representatives

Frame of reference bias
Alas, it seems that we are the centre of our own universe, where translational invariance to another's frame of reference does not apply (unlike the laws of physics). "A recent study of medical residents26 found that 61% reported that 'promotions don't influence my practice,' while only 16% believed the same about other physician's practices. Clearly, it cannot both be true that most physicians are unbiased and that most other physicians are biased!! Furthermore, medical students recognize gifts as more problematic for other professions than they are for medicine."

Interestingly, all this works the other way around too. "Patients, while somewhat more concerned about the possible biasing effects of gifts than physicians, seem to be vicariously self-serving in their perceptions, believing that other individuals' physicians are more likely to be biased by gifts than their own physicians."

The article concludes that, without properly understanding the sources of conflict of interest, it is impossible to make policies to regulate it. They recommend that pharmaceutical gifts of all sizes should be prohobited, as even small is big in this case.