In this study of drug detail visits for gabapentin, we found that most detail visits were brief and of high perceived quality, and often discussed unapproved uses of this drug. Moreover, after receiving the detail visit, half of participants reported the intention to increase their future prescribing or recommendation of gabapentin.
The high perceived quality of these presentations is consistent with the findings of many (but not all) previous studies of physician attitudes toward pharmaceutical representatives [1
]. However, the perceived quality of these presentations may not reflect the validity of their educational content. For example, some of the off-label uses for which gabapentin was promoted are not well supported by high-quality clinical trial evidence [41
]. Other uses such as neuropathic pain and migraine prophylaxis have been found to be effective in controlled clinical trials, yet these trials had not been published during the period that we studied (aside from two trials published in the final month of 1998, near the end of our study period) [42
]. More generally, studies suggest that incorrect or misleading information about drugs may frequently be conveyed in promotional settings [5
], that physicians do not consistently distinguish between correct and incorrect information [5
], and that it is the perceived (rather than actual) quality of information that produces behavior change [49
]. In our study, the association between perceived informational value of details and self-reported behavior change was in the expected direction, but did not meet statistical significance.
In addition to the credibility of the information provided at detail visits, the interpersonal aspect of interactions between pharmaceutical representatives and physicians has been hypothesized to be a major driver of behavioral change, and has been emulated with good success by “academic detailing” [1
]. Unfortunately, the forms used for this analysis provide little information about this interpersonal content and its relationship to future behavioral change. Among the visit characteristics that we were able to measure, physicians who received details in small group settings were more likely to increase their future use or recommendation of gabapentin than physicians receiving one-on-one details. This may reflect a “group-think” mentality whereby the perception that one's colleagues are receptive to the detail visit increases one's own receptivity [22
The variables that were not associated with future behavior change may be as interesting as those that were. In particular, physicians reported similar increases in future prescribing or recommending of gabapentin after exposure to approved or unapproved messages, suggesting potential susceptibility to discussion of new and relatively unproven uses. Also, visit duration was not associated with the frequency of future behavior change on bivariate analyses. While the failure to detect an association may be due to our limited sample size, even so 50% of these brief visits were associated with reports of increased future use or recommendation of gabapentin. This suggests that even brief encounters may have substantial impact. This may reflect the success of sophisticated marketing techniques that enable pharmaceutical representatives to track the prescribing patterns of individual physicians and to succinctly deliver tailored marketing messages, employ influence techniques, and regulate the content of the visit all the way down to the firmness and duration of the introductory handshake [10
While we are unaware of other studies published in the medical literature that use methods similar to ours, other reports have found a range of real or perceived impacts of pharmaceutical detailing on prescribing [1
]. Several studies have found positive associations between the frequency of interactions with sales representatives and prescribing behavior, and in physician self-report studies approximately one-third to two-thirds of respondents perceive themselves to be influenced by pharmaceutical sales representatives, although more believe that “other physicians” are influenced [15
]. Studies using objective data on prescriptions have found a consistently positive impact of detailing on prescribing, often with a greater impact than other forms of marketing such as direct-to-consumer advertisements [1
]. For example, major effects were observed in a small study of a resident-run psychiatry clinic [19
]. Other studies have observed more modest effects, with substantial variation in the effectiveness of detailing for different drugs [18
]. The strong effects observed in our study may in part reflect the market position of gabapentin, which at the time of the study was relatively new and of substantial interest for a growing number of conditions, a situation in which the effectiveness of detailing may be greatest [1
Certain characteristics of detailing for gabapentin may not be universally applicable to detailing for other drugs. Most notably, the promotional campaign for gabapentin involved multifaceted efforts to encourage prescribing for uses not approved by the FDA [29
]. As a result, detailing for this drug may have involved an atypically high number of unapproved messages (although a study from France suggests that discussion of unapproved uses may be common for other drugs as well) [23
]. In addition, excitement in the medical community about novel uses of gabapentin may have made physicians particularly receptive to these messages.
Other visit characteristics, such as the duration and perceived informational value of the visit, may be more applicable to other drugs. However, our data do not allow us to test this hypothesis, and our results should thus be interpreted as a case study of detailing for one drug. Nonetheless, the focused nature of our data also represents a unique strength, as attention to a single product and individual visits helps avoid the generalizations and recall biases that may affect most existing surveys of pharmaceutical detailing.
Our study has several limitations. First, the perceived acceptability of providing certain answers to the market research firm could have affected physician responses to this self-reported survey or affected their conduct in interactions with pharmaceutical sales representatives. Second, we have limited information about the content of detailing interactions other than a brief “main message” recorded by the physician. Discussion of unapproved uses may have been initiated by the physician. Third, the self-reported intention to increase future prescribing or recommending of gabapentin might have been affected by factors other than the detail. Thus, we cannot prove a causal relationship between the detail and self-reported behavior change, and we do not know whether future intentions became future actions. Fourth, in our multivariable model the presence of prior visits and the distribution of samples were both collinear with the current level of prescribing, which impacted our model construction. Thus, we cannot reliably disentangle the effects of each of these factors on intentions to increase future prescribing. In addition, the small sample size limits the precision of the observed point estimates and our ability to detect all but the strongest associations. Fifth, although we did our best to focus on the classic form of detailing, it is possible that our sample inadvertently included contact reports from other types of interactions. Finally, as described earlier it is unclear why most of the forms provided in request to the subpoena were from 1996, when the period covered under the subpoena was much broader.
While new forms of marketing such as direct-to-consumer advertising have captured the attention of the medical community, drug detailing remains a major form of pharmaceutical promotion, with expenditures of US$6.7 billion per year helping to pay tens of thousands of sales representatives (estimated at one representative for every 4.7 office-based physicians) [63
]. We found that detail visits for gabapentin often involved messages about unapproved uses and were perceived as having high informational value. Despite the brevity of these visits, half of the respondents indicated their intention to increase their future prescribing or recommendation for the drug. In light of the potential for transmission of unbalanced information and the impact of detail visits on prescribing, the most prudent course of action may be for physicians to curtail or abstain from detail visits, and instead turn to the variety of free and low-cost resources that provide a more objective perspective on the merits and pitfalls of new drugs (http://www.ohsu.edu/drugeffectiveness