Patients Prefer Pictures to Numbers to Express Cardiovascular Benefit From Treatment

We agree that while patients might prefer RR, that information presented in this manner may be misleading and that AR is preferable. In other words, while patients might prefer it, we do not see RR as an acceptable means of expressing these types of information. We are currently conducting a much larger study looking at how patients with a range of CVD risk (from 5% to 30%) rank various ways of numerically and pictorially expressing risk, both as to which would most encourage them to action and which is the most helpful to them to understand their risk and the possible benefits of making changes. This study also addresses decision-making.

We are asking patients both what format of information most encourages them to take a medication, and what format helps them best understand. These are often quite different. It is not best practice to merely present patients with information that might overly encourage them to embark on life-long medication (which unlike our hypothetical drug, will have harms as well as risks). Our study is attempting to understand what formats might be unduly coercive to patients.

We agree that not all patients will prefer or understand information presented in a certain way and ideally physicians should have available a range of options to explain risks and benefits. We also agree that patients may decline to take potentially helpful medications or to make lifestyle changes that might reduce their risk of illness. This is their choice, not ours. Our role is to provide them with information in a form that they can understand, that makes sense to them, in order for them to make these decisions.

Competing interests:   None declared

Goodyear-Smith and colleagues offered 100 patients with cardiovascular disease a theoretical choice: whether or not to take a medication for secondary prevention, depending on how the benefits are presented.1 Patients overwhelmingly chose the medication regardless of how the information was portrayed. One exception was the use of NNTs, which caused patients to feel less certain and less “encouraged” to take it.

I agree with Dr. Krones that selection bias may be at play here; some of the study’s language hints at a pro-treatment bias on the part of the authors. Rather than ask about patients’ willingness “to take daily medication for the rest of their lives to protect their hearts,” would more treatment-neutral phrasing, such as “to potentially reduce the risk of heart attack”, have altered the results?

The authors’ choice of the 4S Study for the theoretical medication requires some scrutiny. Some data suggest that 4S was skewed towards higher risk patients, given the more conservative results from later studies such as CARE2 and LIPID3, whose 5 year NNTs for major coronary events were at least twice as high. The use of the optimistic 4S results in the absence of risk and cost data presented the patients in this study with a proverbial “no brainer”– take a pill and reduce your risk without potential hazard. Were the less sanguine patients (the 11-26% who would not be encouraged to take it) the same individuals as the 19% who were unwilling “to take daily medication for the rest of their lives to protect their hearts”? Prescriptions are free or highly subsidized in New Zealand. How would these results have differed among our 47 million uninsured, especially if presented with only half the 4S effect size, qualified by out-of-pocket expenses for a statin and liver function monitoring for 5 years, and the caveat that every 7 coronary events prevented would be balanced by an adverse event?4

Most research tends to raise more questions than it answers. How can we study preferences given the uncertain nature of the enterprise and the scant evidence base for our discipline? How do we balance increasing emphasis on shared decision making with pressures to meet measurable quality metrics? Is it necessarily bad that some patients decline potentially helpful interventions once they fully understand the risks and benefits? Why do doctors tend to fall into one of three categories: therapeutic nihilists, positivists, and agnostics? Do our patients fall into similar categories? Why or why not? Finally, how can we assess the true impact of interventions in the messy complexity of real life? After all, we do not practice in a frictionless universe, and all other things are never equal.

1. Goodyear-Smith F. Arroll B, Chan L, Jackson R, Wells S, Kenealy T. Patients Prefer Pictures to Numbers to Express Cardiovascular Benefit From Treatment. Annals of Family Medicine 2008; 6:213-217.

2. Plehn JF, Davis BR, Sacks FM, Rouleau JL, Pfeffer MA, Bernstein V, et al. Reduction of stroke incidence after myocardial infarction with pravastatin: the cholesterol and recurrent events (CARE) study. Circulation 1999;99:216-23.

3. The long-term intervention with pravastatin in ischaemic disease (LIPID) study group. Prevention of cardiovascular events and death with pravastatin in patients with coronary heart disease and a broad range of initial cholesterol levels. N Engl J Med 1998;339:1349-57.

4. Silva MA, Swanson AC, Gandhi PJ, Tataronis GR. Statin-related adverse events: a meta-analysis. Clinical Therapeutics 2006;28:26-35.

Competing interests:   None declared