Impact of pharmaceutical promotion on prescribing decisions of general practitioners in Eastern Turkey

Drug expenditure has been one of the main concerns of health care managers; thus, its containment is one of the primary goals of health care authorities. Therefore, identifying prescribing-associated factors is of paramount interest from health, as much as social and economic standpoints [1–4]. The effects of various factors on prescribing decisions have been considered in many studies [5–7]. The physician's age, training, environment, and health-care demand have been quoted as explanatory factors for prescribing behavior.

As Prosser et al mentioned factors like doctor characteristics, hospital consultants, the pharmaceutical industry and patient characteristics lie behind the prescribing decisions among general practitioners (GPs) [8]. In our study, some factors which were thought to be potentially related with prescribing decisions of GPs were considered. In this context, the number of patients examined per day may be an influential factor on prescribing decisions because the frequency of visits by sales representatives (SRs) to the physicians examining high number of patients per day may tend to be higher. Therefore, high number of patients examined per day means shorter time per patient. Furthermore, shorter time per patient may affect rational decision-making process regarding prescription. Work site is considered as another possible influential factor because daily burden of GPs with regard to number of patients per day in primary health care settings is relatively higher than that in the hospitals in Turkey. As mentioned above, patient per day may be an important parameter to determine the effect of pharmaceutical promotion on GPs. Year of practice of GPs may also affect prescribing decisions. Higher number of practice years may indicate more experience in prescribing, and thus, the influence of SRs on experienced GPs may be lower.

Commercial sources of information are known to have a greater influence than scientific sources on general practitioners' prescribing behavior in under developed and developing countries. Twenty years ago, Avorn et al found that although physicians believed that drug advertisements and pharmaceutical representatives had a minimal effect on their prescribing behavior, they held advertising oriented beliefs about the efficacy of drugs such as cerebral vasodilators and dextropropoxyphene [9]. Recently, in a survey of 200 general practitioners and 230 hospital based doctors, the information on the latest new drug prescribed was derived from pharmaceutical representatives in 42% of cases [10].

A systematic review also found that meetings with representatives were associated with requests by physicians for promoted drugs to be added to the hospital formulary, requiring changes in prescribing practice with increased prescribing costs and less rational prescribing [11]. Therefore, interactions between physicians and drug companies raise scientific and ethical questions.

We considered that the pharmaceutical promotion had a significant effect on prescribing decisions. Patient per day, work setting, year of practice, gender, frequency of sales representatives (SRs) visits, participation in training sessions were expected to be the determinants of the effect of pharmaceutical promotion. The study aimed to determine the self-reported impact of promotional activities by sales representatives of pharmaceutical companies on the decision-making process of drug prescription ordered by the general practitioners (GPs) working in Eastern Turkey.

This cross-sectional and exploratory study was performed with the participation of 152 GPs working at primary health centers and hospitals in order to find the effect of pharmaceutical promotion on prescribing decisions. According to the self report of the GPs, their prescribing decisions were always or sometimes affected significantly if they had participated in any educational activity of pharmaceutical companies and if they were working in primary health care centers, respectively (p < 0.05 for both). The self-reported effect of pharmaceutical promotion on the prescribing decisions of GPs was significantly higher if the GPs were visited by SRs frequently, i.e. more than once a month; examining 60 or more patients per day, and year of practice was 5 years and under, respectively (p < 0.05 for all).

The rate of SRs visits to GPs who had a high burden of patient per day was higher. These GPs also reported high influence by the activities of SRs. These findings may be the key factors to show the effect of pharmaceutical companies on prescribing decisions of GPs. Prosser et al. stated that the characteristics and working conditions of the GPs were generally underestimated while investigating the pathways of the effect of pharmaceutical promotion on GPs [8]. Like Prosser et al, we found that if the GPs were working at primary health care centers and had an experience less than 5 years after graduation, they reported higher influence on their prescribing decision. Additionally, the GPs under heavy burden of high number of patients per day could provide limited time per patient, which may affect the rational prescribing decision in a negative manner. The self-rated effect of pharmaceutical promotion on prescribing decisions was lower for experienced GPs. Total year of practice was found to be another factor to have an influence on the pathway of prescribing decision.

Similar to our study, many previous studies also determined that GPs were affected by promotions of pharmaceutical companies [13–19]. According to several primary care physicians, detachment within the health care system, especially in the traditional primary care model, is exploited by pharmaceutical companies to create personal links with the physicians [20]. This may have an effect on a more positive perception of the quality of the information provided by sales representatives while affecting the physician's prescribing behavior. In a 2001 survey of random sample of U.S physicians, 92% of the physicians received free drug samples from companies; 61% received meals, tickets to entertainment events, or free travel; 13% received financial or other in-kind benefits [21]. These incentives may be dominant for GPs who prescribed high number of drugs. In this study, we noticed that the frequency of the visits to GPs performed by SRs was higher for the GPs with high number of patients per day (Figure 1). This may suggest the presence of the effect of pharmaceutical promotion on GPs.

Of the GPs, 77.0% received education on prescribing. Whereas 53.0% of these only participated in training courses of pharmaceutical companies, the remaining 47.0% received education from both the drug companies and other sources (in-service training, course of universities). It was found that there was a lack of postgraduate medical education provided by public sector (in-service training) in GPs in Eastern Turkey. Thus, participating in educational courses of pharmaceutical companies was common among the GPs. All of the GPs, who had been involved in any pharmaceutical education activity, had received at least one suchlike training programme from drug companies. Patient per day ratio per GP was also significant, indicating the involvement of GPs in training programmes of pharmaceutical companies. This is possibly due to the higher frequent visit of SRs to GPs with higher number of patients per day. Previous studies also determined that most physicians allocate more hours to receiving SRs than to attending updating courses [20, 22]. According to various authors, commercial information makes up for the lack of training in health care services, and this is even more common in developing countries where the drug industry influence is greater[23, 24]. However, postgraduate medical education should not be completely dependent on the initiative of pharmaceutical companies, a well-known issue worldwide [25]. For example, the pharmaceutical industry is also the main provider of information to physicians in Spain [23]. The quality and content of formal pharmacology education during medical faculties is another factor that can directly affect the formation of prescribing decision and the attitudes of GPs towards the relations between doctors and pharmaceutical companies. Critics argue that basic pharmacology rather than problem solving and practical application or audit is overemphasized during medical training in developing countries, and largely responsible for establishing poor prescription habits that subsequently prove difficult to change [26–28].

In our study, drug guides of pharmaceutical companies, medical books, and the documents of pharmaceutical companies other than drug guides were the most commonly used reference resources in case of any problems in prescribing. The most common reference source used by 73.7% of the GPs in this study was drug guides of pharmaceutical companies. It has been reported that 86% of the GPs in Tunisia mainly use drug guides when any prescribing problems arise, and nearly 30.0% do not refer to any medical publications [29]. Drug guides prepared by pharmaceutical companies may have a negative effect on rational prescribing behavior of GPs. Nevertheless, various studies determined the great extent of the effect by the pharmaceutical industry on prescribing behavior of GPs [30, 31]. In our study GPs reported that self-reading after graduation and pharmaceutical promotion were the leading factors that affected their prescribing decisions. As mentioned above, this finding also indicates the lack of in-service training provided by public sector. In addition to this, consultation between GPs and other specialists was quite inadequate. (Table 3). Heavy patient burden might play a role in these inadequate interpersonal consultations. Pharmaceutical companies may fulfill the gaps occurring because of limited communication between physicians.

The findings of this descriptive study were based on self-report of GPs about the effect of pharmaceutical promotion on their prescribing decision. The reliance of self-report is one of the main issues of the studies similar to ours. Blumenthal et al. noted that in a study of residents, it was found that 61% believed that they were not influenced by the marketing efforts of pharmaceutical companies, although only 16% were equally confident about their colleagues [21]. Carthy et al stated that GPs considered themselves as cautious and conservative prescribers. In this study, GPs also stated that they were not unduly influenced by the drug representatives [32]. Like Prosser and Avorn et al. and based on the findings of other studies above, there might be an underestimation of the effect of pharmaceutical promotion on the prescribing decision of the GPs in our study.

As this was a descriptive and exploratory study in a single province of Eastern Turkey, we aimed the enrollment of all the GPs in the area; therefore, we did not use any sampling method. The participation rate was relatively high (96.8%), and this was one of the strengths of our study. This might be due to the support of local health directorate in the enrollment and willingness of the GPs to participate. The official regulations governing the pharmaceutical promotion was arranged by law in Turkey in 2003 and since then it has been in effect. This law provided restrictive mandatory regulations to pharmaceutical promotion. However, the implementation of the regulation was not adequately monitored by Ministry of Health.

This is a unique study, which was conducted in one of the less developed regions of a developing country, Turkey. The results of this study suggest that the promotional and educational courses of pharmaceutical companies were reported to be influential on their prescribing decisions by GPs. In addition to this, for the majority of the GPs, primary reference sources concerning prescribing was commercial information provided by sales representatives of pharmaceutical companies. All these results indicates a lack of formal continuing medical education and an adequate monitoring of prescribing behaviours provided by public sector.