Looking beyond promotional claims

Treatments change a lot over a veterinarian’s working life, so learning about what is new is a professional necessity and should be an integral part of normal work. When a new treatment comes along, there are two questions for the veterinarian: Should I use the new product? Should it replace what I currently use? To answer these questions, it is necessary to see the full safety and effectiveness picture; this means knowing about the disadvantages and uncertainties as well as the benefits of the product.

A company marketing a new product will usually provide information in the form of advertising in the veterinary press and online, at conferences and trade shows, leave-behind materials following company representative visits to the practice, and in prepared talks, often accompanied by free lunches or dinners. While advertising may be helpful in raising awareness about products, the main purpose is to increase their sales. Companies will naturally focus on the product benefits and will not be keen in highlighting disadvantages or compare the product with alternatives. This means the information in promotional material alone is likely to be inadequate for making a therapeutic decision.

While there has been a great deal of research into, and comment on, the nature and effects of pharmaceutical advertising in human medicine,^1,2 the relationship between product promotion and veterinary medicine has hardly been explored. Researchers are now beginning to shed some light on this: a recently published study examined the nature of print advertisements for veterinary products (medicines, diagnostic tests and food supplements/nutraceuticals) in two U.K. veterinary publications.³ It found information required for making therapeutic decisions is usually absent: only 16 percent of the advertisements included references to peer-reviewed sources of information.

Vet med advertising

A key difference between advertising veterinary medicines in the U.S. and the U.K. is that inclusion of regulator-approved prescribing information is a legal requirement in the U.S.,⁴ but not in the U.K.

Print advertisements for medicines aimed at veterinarians in the U.S., therefore, contain a reproduction or summary of the U.S. Food and Drug Administration (FDA)-approved package insert, including the approved indication, quantitative effectiveness, and adverse effects data, as well as contraindications.⁴ Whether this makes a difference to prescribing practices is unknown.

Unlike veterinary medicine ads, which are required to contain regulated product information, diagnostic tests, devices, and supplements are unregulated products, so there is no regulator-approved information.

The study of U.K. advertising found advertisements for diagnostic tests and supplements were particularly unlikely to include helpful information.³ For these products, there is certainly a need to look elsewhere for information to support treatment decisions.

Don’t take it at face value

It is important not to take advertising claims at face value because occasionally claims simply misrepresent or are otherwise not supported by the evidence.⁵ The validity of the claims must always be checked. However, advertising is more likely to exaggerate the benefits of a product or mislead through omission rather than through making false claims (this is my observation as a result of reviewing the promotional claims of new veterinary medicines in Veterinary Prescriber over several years). Below are common pitfalls in promotional literature:

• Highlighting a theoretical benefit. Pharmacological features (such as longer half-life, better absorption, or “selectivity” for a particular receptor) might imply a clinical benefit, but do not necessarily translate into clinical advantages. It is necessary to find out if there is clinical evidence to back up the theory.Another highlighted “theoretical benefit” is quoting epidemiological associations. For example, advertisements for pet wormers in the U.K. have stated Toxocara serological values in humans are positively associated with a risk of epilepsy and negatively associated with children’s academic performance/cognitive development. While these associations are recognized, their inclusion in advertisements for wormers can imply that Toxocara is the cause of epilepsy and reduced academic performance, whereas the epidemiological evidence does not prove this.
• Using vague or emotive claims. Evidence for the efficacy of a new veterinary medicine usually comes from the results of one or two randomized controlled trials (RCT) assessing the effect on a specific outcome measure. For instance, the measure of treatment success with a medicine for reducing pain in canine osteoarthritis might be a reduction of a few points on the pain and interference scores of a validated scoring tool.It can be challenging to translate such results into a benefit that is meaningful to the client. Beware of vague sweeping claims in advertisements that convey an emotionally desirable interpretation of the results and may lead to high expectations of the treatment.
• Not mentioning the likelihood of benefit. The benefits of a medicine are often presented —in advertisements and in the wording of the licensed indication—in qualitative terms only. It is also essential to know the likelihood of benefit and be able to communicate this to the client. For instance, the wording of the claim might conceal a low response rate to the active treatment or a large placebo effect.In the U.S., the package leaflet is required to include quantitative information on efficacy, including the proportion of animals that benefited. From this, it will be possible to calculate a number-needed-to-treat. If there is insufficient quantitative information in the package insert, the full summary of the documents submitted for FDA approval can usually be freely obtained online using the New Animal Drug Application number.
• Not mentioning risks. Typically, advertisements do not mention the nature and likelihood of harm from using the treatment. The nature and likelihood of known adverse effects in the treated animal will be included in the package leaflet. There might be other relevant information in the package leaflet that affects a decision to use the treatment in place of an alternative therapy. For instance, that the product should not be handled by women who are, or might be pregnant, or limitations on the duration of use of the treatment because of a risk of accumulation.

  

Uncertainties not spelled out

As well as knowing the full information about the benefits and risks of an intervention, it is also important to know about the uncertainties and to communicate these to clients. The regulatory information about a veterinary medicine usually spells out some uncertainties, such as a lack of data on the efficacy or safety of the product in certain patient groups (e.g. below or above a certain age; pregnant and lactating animals; disease states such as liver or kidney dysfunction). However other types of uncertainty are usually not explicit.

• Limited knowledge about adverse effects. Knowledge about the adverse effects of a medicine at the time of first marketing is only provisional. This is because veterinary clinical trials are usually too small —typically including only a few hundred animals —to detect anything except the most common adverse effects.⁶ Rarer side effects may emerge only after a drug has been used in a much larger number of animals. Also, the long-term safety of a new treatment is usually unknown because clinical trials of treatment for chronic conditions usually last six months at most. These uncertainties about safety need be taken into account in assessing the benefit-harm balance.
• Limitations of clinical trial evidence. Clinical trials often do not provide answers to important questions such as the efficacy of the treatment in animals with concomitant diseases; at what stage of the disease it is best to use the treatment; and when to use the treatment in relation to other treatments.
• Comparative efficacy. New drugs are often tested in trials that are designed to establish that their effect on a particular outcome measure is better than a placebo. If there is an established treatment, trials are typically designed to show only that the new drug is not inferior to the standard drug (a non-inferiority trial).⁷ This means the trial needs to show the new drug is no worse, within a specified margin, than the standard drug. The benefit of non-inferiority trials is that they usually need a smaller sample size than trials looking for superiority, so they are quicker and cheaper to perform; they are also less likely to produce disappointing results for a new drug. They are also unhelpful for the veterinarian wishing to compare treatments.

Have a critical mind

Acting uncritically on the information supplied by the marketing company may lead to inadequate or misinformed prescribing decisions. It is important to look beyond promotional information. Critical evaluation of a product means that the veterinarian is more likely to use the treatment on the basis of the strength of the evidence rather than the weight of promotion.

---

Andrea Tarr, B Pharm Msc MRPharmS, is the founder and director of veterinaryprescriber.org, an independent online resource that provides objective, evidence-based, and practical information on veterinary medicines without the influence of the pharmaceutical industry. Tarr is a registered pharmacist and has a master’s in evidence-based pharmacotherapy. She is a member of the independent scientific committee that advises the U.K. veterinary medicines regulator. Tarr is also a member of the Evidence-Based Veterinary Medical Association (EBVMA), with different members writing this column. While all articles are reviewed for content, the opinions and conclusions of the author(s) do not necessarily reflect the views of the EBVMA or Veterinary Practice News. For information about the association or to join, visit https://www.ebvma.org.

References

1. Spurling GK,Mansfield PR,Montgomery BD,Lexchin J,Doust J,etal. (2010) Information from Pharmaceutical Companies and the Quality, Quantity, and Cost of Physicians’ Prescribing: A Systematic Review. PLoSMed 7 (10): e1000352.
2. Fugh-Berman, A, Alladin K, Chow J. Advertising in medical journals: should current practices change? PLoS Med 2006 May;3(6):e130.
3. White C, Basham N et al. Cross-sectional survey of sources of information accompanying veterinary product advertisements in two professional print publications. Vet Record 2024. https://bvajournals.onlinelibrary.wiley.com/doi/epdf/10.1002/vetr.3902
4. Code of Federal Regulations. Title 21. 2024. Available from: https://www.ecfr.gov/current/title-21.
5. Veterinary Prescriber. ADVET What the adverts say and what they’re not telling you.. www.veterinaryprescriber.org.
6. O’Rourke DJ. (2016). Adverse events – vets have a key role. Veterinary Practice Today 42 (2): 23-26.
7. DTB. Tests for equivalence or non-inferiority-why? Drug and Therapeutics Bulletin Jul 2008, 46 (7) 55-56.