Gifts to doctors track with heavier prescribing

A Cochrane review ties industry gifts to doctors' prescribing patterns

A Cochrane systematic review pooled 93 studies on pharmaceutical promotion aimed at prescribers, 82 of them conducted in the USA and the remaining 11 in the UK and Europe. The review combines randomized trial data with non-randomized, observational comparisons, a mixed design that lets Cochrane describe associations rather than proven cause and effect.

Sixty-two of the 93 studies focused on gifts and payments. Ten of those studies, covering 2.9 million doctors, found an increase in inappropriate prescribing. Thirty-nine studies, covering 3.8 million doctors, found an increase in the quantity of prescriptions written. Twenty-five studies, covering 2.5 million doctors, found a probable increase in prescription costs. Doctors who had received gifts and payments showed higher rates of inappropriate prescribing and wrote more prescriptions than doctors who had not. Cochrane also reports a consistent pattern across the pooled studies: the more contact doctors had with pharmaceutical companies, the less appropriate their prescribing and the more they prescribed.

The review's authors conclude that these promotional interactions are probably associated with harmful outcomes overall, including less appropriate prescribing, greater quantities of medicine prescribed, higher prescribing costs, and more requests to add a company's drug to a hospital formulary. The evidence is current to January 2025.

Cochrane is explicit that the studies' methods cannot establish that the gifts and payments caused these prescribing changes, and that all of the included evidence comes from the USA, the UK, and Europe, leaving prescribing patterns elsewhere outside the review's reach.