NPC Archive Item: Even limited exposure to pharmaceutical promotion may influence subconscious attitudes to marketed medicines

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18th August 2009

A randomised controlled experiment in US medical students suggests that subtle exposure to small, inexpensive pharmaceutical promotional items influences implicit (i.e. subconscious) attitudes towards branded medicines. No effect was seen on explicit (i.e. self-reported) attitudes towards branded medicines.

Level of evidence:
Level 3 (other evidence) according to the SORT criteria.

Prescribers should not underestimate the potential for even limited exposure to pharmaceutical promotion to influence their prescribing habits.

What is the background to this?
Despite parliamentary regulations, introduced in1994, that ban expensive gifts such as medical equipment and expenses-paid foreign trips from pharmaceutical companies to doctors, the debate on whether small, inexpensive gifts influence prescribing behaviour continues. The current Code of practice for the pharmaceutical industry issued by the ABPI prohibits companies from giving doctors promotional gifts that cost more than £6, excluding VAT. In addition, gifts should be relevant to the recipients work and are more likely to be acceptable if they benefit patient care. ‘Permissable’ inexpensive gifts include stationery items, such as computer accessories for business use, pens, pads, diaries, calendars and clinical items, such as nail brushes, surgical gloves, tongue depressors, tissues and peak flow meters.  However, the assumption that small gifts do not significantly influence doctor’s behaviour has been challenged.

In 2000, an analysis of the literature suggested that doctor-industry interactions appear to affect prescribing and professional behaviour.

What does this study claim?
This study measured the influence of exposure to small, inexpensive branded promotional items on the relative attitudes of US medical students towards two statins, Lipitor (atorvastatin) and Zocor (simvastatin). 352 third- and fourth-year students from two universities with differing policies on interacting with the industry and accepting gifts were included.

It found that implicit (subconscious) attitudes towards marketed medicines were influenced by subtle exposure to small pharmaceutical promotional items in fourth-year medical students. Amongst such students from Miami, where no restrictive policies on interacting with the industry were in place, a statistically significant difference in implicit attitudes was found between those students who were exposed to small branded items (a clipboard and notepaper) at the beginning of the study and those who were not. A stronger preference for Lipitor (which was printed on the promotional items) than simvastatin was seen in the ‘primed’ (i.e. exposed) group. This effect was reversed in students from Pennsylvania, which has restrictive policies on interacting with the pharmaceutical industry. Fourth-year students from Pennsylvania who were exposed to Lipitor (ie the ‘primed’ group) showed weaker preferences for Lipitor compared with those who weren’t exposed (P=0.02).

No significant effect was seen amongst third-year students, and exposure to small branded items had no effect on students’ explicit (self-reported) drug preferences. When a survey was given to students at the end of the study, the “scepticism” scale suggested that those from Miami University, where no restrictive policies were in place, held more favourable attitudes to pharmaceutical marketing than those from Pennsylvania University (P<0.001).

So what?
This study suggests that subtle exposure to pharmaceutical promotion influences medical students’ implicit (ie subconscious) attitudes towards medicines.

However, it is important to note the limitations of these findings. The study was carried out in US medical students, not practicing physicians, so may not be generalisable to UK clinical practice. In addition, the findings were not replicated in third year students. It is unclear why this should be. Further, the study specifically examined attitudes towards specific branded drugs, and did not measure actual prescribing behaviours. The authors did, however, note that attitudes are known to be a specific predictor of behaviours. It is interesting that exposure to the branded product did not influence explicit (self-reported) attitudes, possibly because of social desirability bias in self-reported attitudes.

Even though this study was carried out in medical students, prescribers should not underestimate the potential for limited pharmaceutical promotion to influence their prescribing habits. Current guidance from respected UK bodies, such as that in the GMC Guide to Good Practice 2006, the MHRA’s Blue Guide on advertising and promotion of medicines in the UK and the Quick guide to the Code for health professionals from the PMCPA, which reflect the ABPI code of practice for the pharmaceutical industry should continue to be followed. These include detailed guidance on conflicts of interest and acceptance of gifts, inducements and other benefits from the pharmaceutical industry.

A recent report from the London Royal College of Physicians recommended a gradual cessation of the involvement of the pharmaceutical industry in the education of doctors in training.

Study details
Grande D, et al. Effect of exposure to small pharmaceutical promotional items on treatment preferences. Arch Intern Med 2009;169:887–93

Design: A randomised experimental study

Participants: 352 third (n=191) and fourth-year (n=161) US medical students from two different institutions with different policies on how students interact with pharmaceutical industry representatives. The University of Pennsylvania (n=154) had restrictive policies that prohibit most gifts, meals and samples. However, the University of Miami (n=198) allowed these marketing practices.

Intervention and comparison: Participants were assigned to either a ‘primed’ or ‘control’ group. The ‘primed’ group was exposed to Lipitor (atorvastatin) branded promotional items just before completing a computer-based study instrument. These included Lipitor logos on a clipboard when they signed in and on notepaper, which gave them their identification number. The ‘control’ group went through the same procedure, but using plain, nonbranded clipboard and notepaper.

Following enrolment, students’ Implicit (subconscious) and explicit (self-reported) attitudes towards two statins, Lipitor (atorvastatin) and Zocor (simvastatin) were measured. The Implicit Association Test (IAT), which is widely used in marketing and psychology research, was used to evaluate implicit (subconscious) attitudes. To measure explicit (self-reported) attitudes, students were asked to compare the two statin brands in five dimensions (superiority, preference, efficacy, safety and convenience) using an 11-point scale. Finally, the different attitudes towards pharmaceutical marketing among students at the two universities with differing policies were measured using an anonymous internet-based survey at the end of the study.

Outcomes and results: Whilst students from both universities showed implicit (subconscious) attitudes favouring Lipitor over Zocor, a statistically significant difference (P=0.05) was found between the ‘primed’ and ‘control’ groups among fourth-year students from Miami. In contrast, fourth-year students from Pennsylvania who were exposed to Lipitor (ie the ‘primed’ group) showed weaker preferences for Lipitor compared with the ‘control’ group (P=0.02). No significant effects were seen in third-year students at either university. For explicit (self-reported) preferences, students showed a slight preference for Lipitor over Zocor, but this was independent of the intervention. Students from Pennsylvania showed less favourable attitudes towards pharmaceutical marketing and, using a pharmaceutical marketing scepticism scale, had more sceptical views towards marketing of medicines compared with those from Miami (P<0.001).

Sponsorship: The investigators were supported by the Robert Wood Johnson Foundation, but it was not involved in any aspect of the study.

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