Two studies in the database address this topic. One relies on self-report and is not very useful. The other is an important and useful study that independently assessed relationships with industry and requests for formulary additions.

Lurie’s study⁹⁸ of faculty at seven university teaching hospitals in the USA, and house staff in two of the teaching programmes, found that 20% of faculty and 4% of residents reported recommending additions to hospital formularies at least once in the last year at the suggestion of a sales representative. However, the number of staff who recommended additions for other reasons is unknown.

Chren and Landefeld¹³⁶ showed that doctors who requested that medicines should be added to a hospital formulary were more likely to have received funding from companies than other doctors. They independently observed requests for formulary additions at a university hospital between January 1989 and October 1990. The 40 doctors who made these requests, plus 80 randomly selected doctors who acted as controls, were sent a survey asking about their demographic characteristics and their relationships with the pharmaceutical industry, such as acceptance of money to go to educational symposia, speaking at symposia, and receipt of research funding. They found that doctors who interacted with a company were between nine and 21 times more likely than other doctors to have requested that a medicine made by that company be added to the formulary. The relationship between funding from companies and requests for formulary additions was strong and consistent, and independent of many confounding factors. Chren and Landefeld note that they did not establish causality: and that it could be that doctors learn of a new drug, request its addition to the formulary and then interact with the company. However they suggest that this scenario is unlikely because most requested medicine represented little or no therapeutic advantage over others already on the formulary.

This study provides good evidence that association with a pharmaceutical company - such as receiving research funds - leads to requests for formulary additions. This finding is important because formularies determine the medicines available in a hospital and are therefore likely to affect other doctors’ prescribing habits both in the hospital and when doctors in training leave the hospital and set up an independent practice.

CONCLUSION: Funding for doctors from pharmaceutical companies increases requests for medicines made by these companies to be added to hospital formularies.