LONDON, UK ― New research suggests that more patients than suspected could benefit, or at least perceive benefit, from primary-prevention therapy.
The first part of the study sought to calculate "mean lifespan gain" from a CV-mortality–reducing intervention, in this case a statin, using data from UK records. It showed that only an "unpredictable minority" had significant mortality reductions.
For example, the average lifespan gain was 7.4 months postintervention for 50-year-old male nonsmokers with an average CV risk. But delving into individual data showed that 93% had no gain at all―whereas 7% had a 99-month mean gain. In other words, most had little to no gain while a few of these men, with identical characteristics, had large gains.
Interestingly, in a survey of nearly 400 participants, 33% said they'd prefer a 2% chance of being part of a "large gains" minority instead of accepting a certainty of smaller gains.
Principal investigator Dr Darrel P Francis (National Heart and Lung Institute, London, UK) told heartwire from Medscape that many people want to gamble for the possibility of a bigger payoff. "Many patients want to know, 'What's the size of the jackpot?' So when talking to patients, maybe we really should use the language of lotteries," he said.
Other findings showed that the number of individuals who benefit was greater in those with a higher vs lower level of CVD risk. However, the amount of lifespan gain was similar between the groups. In addition, a greater lifespan increase was found in those who started a primary-prevention intervention at an early vs later age.
The study, led by Dr Judith A Finegold (National Heart and Lung Institute), was published earlier this month in Open Heart.
Dr Ethan Weiss (University of California San Francisco) told heartwire that rather than a lottery analogy, he likens the results to buying insurance.
"It's not talking to patients about a win, it's talking to them about a loss," said Weiss, who was not involved with this research. "For fire insurance, I'd be subsidizing the very rare events that could happen. I may not have a fire and never know if I would have had a fire. But if I do have a fire, at least I'm protected," he explained.
"These are the types of conversations we're good at having when it comes to implantable cardioverter defibrillators―that they're basically insurance policies. Rather than a win, like with a lottery, it's more about preventing risk."
Benefits "Far From Uniform"
CV risk is currently assessed "over fixed time windows that are typically much shorter than a healthy individual's life expectancy," note the investigators. So when discussing primary prevention with patients, "clinicians do not have information on expected impact on lifespan or how much this differs between individuals."
In this study, lifespan gain from an intervention was calculated using published UK mortality data. And probability distribution of lifespan gain on an individual level was calculated using a simulation for patients with the same CV risk profiles.
"It is notable that although risk and absolute risk reduction from intervention increases with age, this does not translate into mean lifespan gain increasing with age of initiation of intervention," report the researchers.
Instead, potential lifespan gain decreased as the age at initiation increased. For example, initiation at 50 years produced a gain that was almost two to three times that of someone who initiated treatment at 80 years.
In addition, in-person, on-the-street surveys were conducted between May and June 2014 in three UK cities and included 396 participants (55% men; mean age 40 years; prior MI or stroke 4%). All were asked to choose their preference of a certainty of receiving a 1-year lifespan gain or some small chance of receiving 10 years of gain.
More respondents chose the certainty option when the higher gain only had a 2% to 10% chance of happening. However, more chose to gamble if there was a 20% chance of gaining 10 years vs the certainty of 1 year, and a huge majority chose a 50% chance of higher gains vs the certainty of 1 year.
Overall, "our study shows that the probability distribution of expected benefit from primary prevention therapy for individuals starting from an identical baseline is far from uniform,” write the investigators, adding that the survey suggests lifespan gain should be presented in terms that explain probabilities.
"Maybe we should just tell people they have a chance of a 10-year life-expectancy extension from taking this medication. And if they ask you what the probability is, then you can do their risk calculations," said Francis.
"But most people are very interested in the size of the payoff and not the probabilities," he added.
"Plain Language" Needed
"Conclusions such as [these] have important implications for clinical practice and so should not be accepted unthinkingly,” writes Dr Rahul Bahl, an associate editor of Open Heart, in an accompanying editorial.
"It's important to remember that, even though the paper is based on real UK mortality figures, the findings are the result of hypothetical modifications," he writes. "It is a statistical thought experiment."
Bahl adds that it's unlikely the results could be confirmed with real-world data. In addition, although the study showed that statins were of more benefit to those who started treatment earlier and could therefore "be advisable for virtually everyone," he noted that many people would call that a step too far.
"Perhaps a better option is to share these decisions with patients so they can be made in collaboration, depending on patients' own risk levels and how they weigh these up," he writes.
Weiss agreed, noting that the study "provides a great stimulus" for patient conversations. "I don't think we do a great job discussing risk in medicine, particularly long-term risk."
He said that the study's take-home message is that nobody knows which patients will benefit from these treatments and which won't, "just like we don't know which houses will burn down. That's why we buy insurance," Weiss reiterated.
"Until we get better at prediction, we're going to have to cast a wider net in prevention. It's reasonable to point out to people that the absolute benefit to them is probably relatively small. But it's also reasonable to point out that we don't know if they're one of the few who might benefit."
He also pointed out that most patients don't understand probability very well. "So it's important to explain some of these complicated statistical concepts in a little more plain language that they can relate to."
The study was funded by the British Heart Foundation and National Institute of Health. The study authors, Bahl, and Weiss report no relevant financial relationships.
Heartwire from Medscape © 2016 Medscape, LLC
Cite this: Should Clinicians Change How They Talk Statins With Patients? New Study Says Yes - Medscape - Mar 24, 2016.