Positives and Negatives of DTP Advertising of Prescription Medications with Regards to the Consumer/Patient

Discussion

 

When carrying out the search of the literature, a robust search strategy was used, and supplementation of the results of the electronic database with hand-searching and searching reference lists allowed confidence in the conclusion that all relevant research was included in the systematic review. Therefore, any conclusions drawn from this review can be based on synthesis and interpretation of all available evidence that is relevant to the topic at hand.

This systematic review has sought to understand the positives and negatives of DTP advertising of prescription medications with regards to the consumer/patient. Particular outcomes of interest have focussed on the diagnosis of disease, the sales and/or use of prescription medicine, medication adherence, utilisation of healthcare, and changes in risk behaviour. Where available, differences in the effect of DTP advertising by ethnicity, age and participant characteristic were also explored.

There is vigorous debate surrounding the positives and negatives of DTP advertising. Skeldon and colleagues highlight both sides of the argument reporting that opponents typically suggest that DTP advertising leads to over-diagnosis, over prescribing, greater adverse reactions to drugs, and increased healthcare costs, while proponents maintain that DTP advertising raises awareness, especially among underdiagnosed diseases, and leads to needed increases in diagnostic testing and treatment (Skeldon et al., 2015). In 2005, a systematic review including only 4 studies generally found that DTP advertising of prescription drugs has a negative impact on the patient/consumer (Gilbody et al., 2005). The review observed increased prescribing of advertised drugs, and increased requests to physicians of advertised drugs. No positive aspects for the patient were observed.

One of the objectives of this review was to understand the impact of DTP advertising on the sales and/or use of prescription medicine, whether that medicine was the one being advertised or a different one. A number of studies included in this review showed that exposure to DTP advertising was consistently associated with increased prescribing of medications including asthma medication (McRoy et al., 2016, Daubresse et al., 2015), varenicline (Kim et al., 2015), statins (Niederdeppe et al., 2013), medications for gastroesophageal reflux disease and social anxiety disorder (Khanfar et al., 2009), treatment for overactive bladder disorders, and medications for onychomycosis (W‘t Jong et al., 2004). In general, the greater the exposure to DTP advertising, the greater the increase in prescription drug use. Interestingly, exposure to DTP advertising could increase prescribing of the advertised drugs, but also drugs that had not been advertised, but which were alternatives to the advertised drug. Despite the prevalence of low and very low quality studies in this review, the consistency of the findings suggests that there can be confidence in the finding that DTP advertising is associated with increased use of prescription medicine, though future high quality research is still required in order to be completely certain. From these studies included in the review, it is not clear whether the increased use in prescription drugs was a necessary or unnecessary part of treatment for the patient. It is possible that this increased prescribing resulted from this practice, which increases the possibility of unnecessary side effects or other unwanted outcomes. . Indeed this argument is central to the proponents of (Skeldon et al., 2015).

It has been suggested that DTP advertising of prescription drugs may lead to an over-diagnosis of disease as people who do not have a disease seek out treatment and diagnosis on the basis of a false positive, and sometimes harmless symptom (Hoffman and Wilkes, 1999). In this review, only one study explored the impact of DTP advertising on new diagnoses of disease (Niederdeppe et al., 2013). This survey of adults in the USA showed that DTP advertising of statins can increase the odds of being diagnosed with high cholesterol in both men and women and also that exposure to direct to consumer/advertising of statins was associated with increased sales of statins. Importantly, the increased diagnosis was most likely to occur in people who had a low risk of a future cardiac arrest. This suggests that DTP advertising can lead to over diagnosis and over-treatment and is not catching those who most need the advertised drug. These findings are consistent with other findings in the research literature (Spence et al., 2005, Lexchin and Mintzes, 2002). It should be noted that this conclusion is based on only one study that was included in this review, and it should also be noted that it scored as a ‘low’ for methodological quality. More research is required to fully understand whether DTP advertising leads to over-diagnosis or over-treatment. Future research should aim to capture not just whether a diagnosis was made, but how the diagnosis was made, and how closely the symptoms exhibited by the patient match the required criteria by the International Classification for Disease and Injury Codes. In doing so, this would enable a platform to better understand the relationship between DTP exposure to advertising and over-diagnosis and over-treatment.

A potential negative consequence for the patient/consumer identified by the present review was the notion that DTP advertising and rates of prescribing of varenicline were strongly associated despite the fact that at the time, the drug safety profile of varenicline was not well established (Kim et al., 2015). As such, the relationship between exposure to DTP advertising and prescribing practices observed in this study, alongside others, represents a disservice to consumers/patients and therefore supports an argument to limit DTP advertising for newly approved products when their real-world safety is not clear. This is an important consideration that needs to be taken into account in any regulatory framework of DTP advertising. Specifically, clinical trials for drug approval need to be designed in such a way that they have the power to detect rare but substantial adverse effects, and there should be stronger regulatory limits on new drugs.

A moderate quality time series analysis in this review has shown that DTP advertising of a new drug leads to increases in the prescription of that drug, but larger increases in prescriptions of the recommended first-line drug (Skeldon et al., 2015). This finding may suggest that DTP advertising campaigns might increase the overall levels of clinically recommended drugs more so than the actual drug that is being advertised. Commonly, critics of DTP advertising argue that advertising can increase inappropriate prescribing (Hoffman and Wilkes, 1999). To agree with this sentiment, it is necessary to believe that the views of healthcare professionals are strongly influenced by the preferences and requests of the patient or consumer. However, the study by Skeldon and colleagues does not support this claim (Skeldon et al., 2015). The findings of this study suggest that when a patient requests the advertised drug, healthcare professionals instead correctly prescribed the first-line treatment, thus clinicians adhere to professional standards and prescribing protocols. It is possible that patients, upon being exposed to DTP advertising, sought knowledge about the drug and themselves discovered the first-line treatment and instead requested that, however this is less likely given the authority healthcare professionals have in the prescribing process. Nonetheless, the study by Niederdeppe and colleagues might imply that DTP advertising itself leads to over-diagnosis and treatment (Niederdeppe et al., 2013), so even when patients were being prescribed the first-line treatment, they may not have needed it at all. Interestingly, in a small sample of patients with urinary incontinence, half of those who reported symptoms and sought a treatment as a result of DTP advertising were not appropriate candidates for the advertised medication (Meade-D’Alisera et al., 2001). This highlights the notion that patients might make an unnecessary referral as a result of DTP advertising.

Work outside of this review has shown that prescribers in primary care can indeed be influenced by patient requests (Kravitz et al., 2005). For pseudo patients expressing symptoms of major depression, rates of antidepressant prescribing were 53%, 76%, and 31% when making brand-specific, general, and no requests, respectively. In adjustment disorder, antidepressant prescribing rates were 55%, 39%, and 10%, respectively. Similar to the work by Niederdeppe, requests for an advertised brand increased prescribing of that brand, but also generic drugs of the same brand and these findings suggest that patients can influence their prescribers. This conclusion is corroborated by a study in the Netherlands that showed increases in the prescribing of onychomycosis following a campaign which decreased significantly once the campaign had ended (W‘t Jong et al., 2004). The fact that prescription rates increased following a campaign and decreased following the end of the campaign suggests that patients play a strong role in requesting medications from their healthcare providers.

Only a handful of studies included in this review aimed to explore the impact of DTP advertising by different characteristics, however a low quality study showed that while older people (75 years and over) were less likely to report asking for a prescription as a result of exposure to advertising, they were more likely to have their request fulfilled than their younger counterparts (Datti and Carter, 2006). This may be as a result of the fact that older people more genuinely expressed symptoms of a disease, or may result from the fact that clinicians are hesitant to unnecessarily medicate younger patients. Findings from the study suggested that DTP advertising can influence the patient-doctor relationship as well as the drug acquisition of patients. This study showed that younger people are more likely to request prescription drugs from their doctors. This might be because the advent of DTP advertising is a relatively recent phenomenon. As such, this suggests there will be an ageing cohort of young people who are currently more likely to request a prescription who may continue to through to their old age, at which age the doctor is more likely to prescribe medicine. This age period cohort effect should be kept at the forefront of researchers minds, as it may be that a huge increase in prescription drugs is yet to come when young people reach old age and replace those who are currently aged over 75 years. In this way, the true impact of DTP advertising may not yet have been measured. Future research should aim to unpack what medications have been requested and if results differ as a function of the type of medication. For example, mood altering substances, or medications open to abuse, such as opioids, may be less likely to be prescribed upon request.

Work by Schommer and colleagues indicated that individuals with a better patient-physician relationship were more likely to request a prescription drug as a result of DTP advertising than those who reported a poorer patient-physician relationship (Schommer et al., 2005). This suggests that the patient-physician relationship might be an important predictor of how individuals respond to direct consumer/patient advertising. However, this study was of low quality and more research is required to fully understand the impact of this relationship. Nonetheless, differences in the patient/physician relationship should be borne in mind when trying to unpick the differences in the positives and negatives of DTP advertising across countries. It is possible that the finding of a positive patient-physician relationship relates to the observed finding in relation to age; that older individuals are less likely to ask for a medication, but more likely to receive it when they do (Datti and Carter, 2006). This could be because patients have had longer to build a relationship with their doctor, and their doctor feels more comfortable prescribing medication to someone who they have known for a long time and have a full record of their medical history.

A study included in this review revealed important ethnic differences in the response to DTP advertising, showing that African Americans were more likely to ask their physicians for a drug that they had seen advertised and also more likely to have their request refused (Lee and Begley, 2010). This raises an important issue relating to health inequalities in race resulting from DTP advertising, but also an issue relating to provider-patient relationships. All participants in this study were from the USA and it is not clear whether the differences observed across ethnicities relates to differences in health inequalities across these groups or a difference resulting from racial beliefs of prescribers in the USA. Certainly this work needs to be replicated in other countries in order to fully understand the effects of DTP advertising.

While this review has shown that, in general, exposure to DTP advertising increases rates of prescribing for a range of diseases, an important consideration is the spill-over effect of DTP advertising on other non-pharmaceutical behaviours. That is, whether exposure to DTP advertising of prescription drugs leads to changes in behaviours such as exercise, smoking, dietary intake, or alcohol consumption. Only one study in this review explored the effect of DTP advertising on risk behaviours and showed that statin advertisements were shown to increase exercise frequency, but also visits to fast-food restaurants (Niederdeppe et al., 2017). While these findings are somewhat contradictory, it is not clear if those who engaged in exercise to improve their cardiovascular health simultaneously engaged in a behaviour that reduced cardiovascular health. It is possible that this study is actually measuring two groups, perhaps the treated and untreated. Those who are not treated with statins may see an advert for statins which reminds them of the risks of cardiovascular disease and therefore carry out a cardiovascular health activity such as exercise. For those who are treated with statins, exposure to a statin advert may give them inappropriate confidence in the efficacy of statins and therefore engage in cardiovascular risk behaviours such as eating fast-food. Both of these are interesting hypotheses which could benefit from future research. It is possible that this effect is mediated by those with and without health insurance, and this should be considered in future research.

A key objective of this review was to understand the impact of DTP advertising on the use of healthcare. Overall there were mixed results according to the type of healthcare, and by different diseases. For example, DTP advertising was associated with increases in outpatient visits for high cholesterol among those aged between 18 and 45 years, but not among those aged between 46 and 65 years (Chang et al., 2017). Furthermore, exposure to DTP advertising for asthma medication was associated with increases in emergency room but not hospitalisations or outpatient admissions (Daubresse et al., 2015).

It has been argued that pharmaceutical companies may use DTP advertising as a means of increasing market size or share. As such, DTP advertising may not be a legitimate source of unbiased information and thus represents a negative from the perspective of consumers/patients. The present review did not carry out a content analysis of adverts and did not measure changes in knowledge or awareness in those who are exposed to DTPs advertising. Despite this, a systematic review which attempted to understand the economic and clinical implications of DTP advertising did show that these claims were largely supported by the published literature (Gilbody et al., 2005). As such, the changes demonstrated in this review may not be authentic, clinically positive changes, and may indeed be unnecessary treatments in patients who do not need treating, thus representing an unnecessary increase in the costs of treatment.

While this review did not identify any evidence evaluating the cost-effectiveness of DTP advertising, wider research argues that advertising of DTP prescription drugs increases market competition, which in turn can reduce the price of prescription drugs and increase research and new development of drugs. For example, between 1997 and 2001, spending on research and development in the USA increased by 59% while spending on DTP advertising increased by 145% (Hollon, 2004). It is possible however that funding for research and development is determined by wider factors than market competition.

A large number of studies identified by this review were published commentaries or opinion pieces on the positives and negatives of DTP advertising of prescription drugs and were therefore excluded from this review. The sheer number of commentaries or opinion pieces perhaps represents the vehement debate in this research area. However, it is interesting that primary research measuring dependent variables is perhaps lacking in comparison. One opinion piece by Lexchin and Mintzes is strongly opposed to DTP advertising of prescription drugs (Lexchin and Mintzes, 2002). The authors argue that DTP advertising is not warranted, because new drugs do not necessarily offer therapeutic advantages, DTP advertising does not bring advances in medicine to the attention of the public, and because drugs subject to advertising may have unfavourable benefit/harm ratios. These are all important considerations, but not ones that can be understood from the studies included in this review for the reasons discussed previously.

Despite pressure from the pharmaceutical industry to allow DTP advertising of prescription medications, it is banned in most of the world with the exception of the USA, New Zealand and Brazil. While the former were permitted from the 1980s, though may have only been used to its full effect in the last few decades, Brazil has permitted pharmaceutical DTP advertising since 2008. In all other countries, DTP advertising of prescription drugs is not permitted. Overall, the findings of this review suggest that the evidence base is not yet strong enough to make firm conclusions regarding whether the impact of DTP advertising is positive or negative, meaning that a precautionary approach might be most appropriate. The precautionary principle states that “if an action or policy has a suspected risk of causing harm to the public, in the absence of scientific consensus (that the action or policy is not harmful), the burden of proof that it is not harmful falls on those taking that action”  (Martuzzi and Tickner, 2004). Invoking the precautionary principle is most useful where there is the possibility of harm from making a certain decision, and when extensive scientific knowledge on the matter is lacking. As such, areas that have banned DTP advertising may be seen to have invoked the precautionary principle, an appropriate action given the potential risk of harm. Indeed, New Zealand, the USA and Brazil, may benefit from further regulating the advertisement of prescription medicine, in order to adhere to the precautionary principle and reduce the risk of harm. Having said this, it is highly unlikely that the pharmaceutical industry will allow this restriction on their advertising, given their political and economic power in New Zealand and particularly the USA (Castellblanch, 2003). In these counties, changes to existing legislation to reduce harm might be a more realistic aim. This could include limiting the advertisement of new drugs, given that this review has shown that there may be issues with the real world safety of new drugs that need better exploration through research studies. Indeed, David Rothman quoted “when commerce joins with ideology, we have a powerful engine to promote change” (Rothman, 2001).

Considerations need to be given to what is classified as ‘DTP advertising’ as well. This review identified a study carried out in the Netherlands, which health professionals argued to be an advertising campaign, but which industry actors described as an information campaign. As such, clear definitions of what constitutes an advertising campaign are required. Similarly, there might be an issue with cross-border advertising. Cross border advertising is when viewers in a country are exposed to advertising that is permitted in a different country if they have access to the same media as in other countries. This is of particular relevance to Canada, where they may see adverts on American television channels (Mintzes, 2009). Indeed, a time series study including 2,700 Canadian pharmacies, it was shown that DTP advertising in the USA influenced Canadian prescribing rates (Law et al., 2008). Again, this research showed that viewers were exposed to advertising of a drug that was later withdrawn due to safety concerns. Nonetheless, this research showed that DTP advertising is a relevant issue for cross-border media advertising and needs to be considered when countries choose to air media channels from other countries. Other research has highlighted concerns with cross-border advertising, concluding that “direct to consumer [patient] advertising is no longer confined within physical or geographical boundaries. Similar to the ease of transmission of diseases through increased international trade, travel, and communication, DTP advertising has globalised to markets outside of the USA and New Zealand via the Internet and other forms of cross-border promotion” (Mackey, 2012). As suggested earlier, it was recognised that the harms of cross-border advertising is largely unrecognised in the research literature to date and there is a lack of global discourse and global health governance to address this issue. Indeed, the globalisation of DTP advertising may pose a particular problem or public health threat for countries with emerging markets where DTP advertising are prohibited, yet are still accessible, and are very difficult and expensive to regulate.

A large majority of the work in this review was observational in its design and was therefore rated to be ‘low’ or ‘very low’ quality. This reduces the confidence in the estimate and increases the chance that future studies will be likely to change the estimate of effect. Nonetheless, it should be noted that the exposure of DTP advertising of prescription drugs is not necessarily amenable to measurement using RCTs, and the overemphasis on RCTs as ‘gold standard’ has been argued to be unhelpful, and tends to ignore many limitations of RCTs (Black, 1996). Future research in this area, particularly research that utilises more sophisticated research designs, should ensure that the relative impact on patients/consumers is a high priority outcome. It should also be noted that some studies in this review depended on the self-reported experience of patients. It is possible that there is bias in patients’ self-reports. This means that future research which uses a self-report measure needs to also collect a verified measure of the patient’s report, such as doctors’ notes or actual medications prescribed and the course of treatment that the patient reports being on.

Given that direct to consumer/patient advertising of prescription drugs is only permitted in the USA, New Zealand and Brazil, most of the research has been carried out in these countries. Indeed most of the research included within this review originated from the USA. While no countries have recently expected a desire to permit direct to consumer/patient advertising in the near future, it should be noted that the vast majority of the extant literature would not be generalisable, particularly for low income countries. As such, should countries wish to explore introducing direct to consumer/patient advertising, ideally culturally-relevant research exploring the impact should be prioritised prior to implementing any new legislation

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Reflexivity

“A researcher’s background and position will affect what they choose to investigate, the angle of investigation, the methods judged most adequate for this purpose, the findings considered most appropriate, and the framing and communication of conclusions” (Malterud, 2001, p. 483-484).

some may see these different ways of knowing as a reliability problem, others feel that these different ways of seeing provide a richer, more developed understanding of complex phenomena.

Working within medical communications and specifically working on DTP advertising campaigns could have impacted the ability of the writer to impartially view the findings of this research however .  As Malterud (2001) writes: “Preconceptions are not the same as bias, unless the researcher fails to mention them”.