By Douglas L. Beck, AuD, F-AAA, CCC-A
The highly anticipated results of the ACHIEVE (Aging and Cognitive Health Evaluation in Elders) study were published in The Lancet July 18, 2023. This extremely important study offers new insight into the links between hearing intervention and reducing cognitive decline in older adults with hearing loss as well as opportunities for multiple disciplines, some of which we explore here with Jennifer Deal, PhD. She is an epidemiologist and gerontologist at Johns Hopkins Bloomberg School of Public Health and Otolaryngology-Head and Neck Surgery at Johns Hopkins University School of Medicine who has been involved in the ACHIEVE study since 2018, providing her with an interesting perspective from which to offer her insight and analysis.
Beck: Why don’t we start by explaining what an epidemiologist is, as that’s your primary role at the Bloomberg School of Public Health.
Deal: Epidemiology is the science of public health. It’s the study of health in populations, including describing the distribution of disease in a population, and what factors influence that distribution. We also try to understand causes of disease so we can make change and improve population health, which is very much what we tried to do with the ACHIEVE study.
Further Reading: Hearing Aids May Slow Risk of Cognitive Decline in Older Adults
Beck: And this is a good time to note that ACHIEVE is an acronym, which more or less stands for Aging and Cognitive Health Evaluation in Elders. The ACHIEVE study was just published in The Lancet (July 18, 2023) under the title “Hearing Intervention versus health education control to reduce cognitive decline in older adults with hearing loss in the USA (ACHIEVE): a multicentre, randomized controlled trial.” The study involved four sites across the USA, and the participants ranged from 70 to 84 years when they entered the study, and their participation went on for about three years?
Deal: Yes, that’s right. The study itself was three years in duration, but as you know, Doug, it took years of preparation. From 2017 to 2019 we screened over 3,000 people to determine the actual participants. We drew participants from two populations. The first was the ongoing ARIC (Atherosclerosis Risk in Communities) study and the others were “de novo” participants (i.e., “new people” who were not previously enrolled in ARIC). In the final analysis we had just under 500 people in each of the two studied groups.
Group one was assigned to health education, which consisted of multiple conversations about healthy aging. Group two was the hearing intervention group. Group two received bilateral hearing aids fitted via nationally recognized best practice standards, by audiologists. They received other rehabilitation too, including technology to pair with the hearing aids and strategies to improve communication. Of note, the mean age of the entire cohort was 76.8 years, 54% were female, and 88% were White.
Beck: And if I recall from the publication, the ARIC participants were generally older, had more risk factors regarding cognitive decline, and actually had (in general) lower cognitive scores than the de novo group?
Deal: Yes, that’s correct.
Beck: So then, when comparing the outcomes of groups one and two, what did you find?
Deal: In general, we found that over three years, there were essentially no differences in the cognitive outcomes across groups one and two. The results were statistically the same.
Beck: And so, as an “epidemiologist-wanna-be,” I would note that no difference between the two groups doesn’t mean there wasn’t an effect, it means that whatever the effect was (or was not), it was essentially the same across the two groups. There was no “untreated” group. More specifically, both strategies may have been proven beneficial if compared to a no treatment group.
Deal: Excellent point, you’re right. In fact, when we do studies like this, we always have to limit what we’re studying, how we’re going about it, and we have to relate and interpret the results with regard to the protocols and goals of the study. In this study, the question we addressed was, “Is there a difference between professionally fitted long-term hearing aid outcomes and best-practices hearing rehabilitation versus long-term health education, with regard to cognitive decline?” And to that question, the answer is, “No.” However, the point you raise is correct, we did not compare it to “no treatment.”
Beck: Perhaps another important issue is that the ACHIEVE study does not make statements at all regarding over-the-counter (OTC) products, as the fittings for the study were done using excellent prescription devices fit to nationally recognized best practice protocols. However, when you examined the treatment group participants (the people who received hearing aids) who were already enrolled in the ARIC study, you did see some interesting trends.
Deal: Yes. In the sub-group who were recruited from ARIC, we found that the hearing intervention reduced overall cognitive decline over three years. One interpretation for finding an effect for that group but not for the de novo group may be that ARIC participants were older and, given their other characteristics, may have been at increased risk for cognitive decline. However, we didn’t see an effect for the de novo group, who potentially weren’t at increased risk for cognitive decline.
Beck: Very interesting! When I examined the ACHIEVE results, and given that cognitive screenings are considered best practices for audiologists by AAA and ASHA, it seems the “take home message” may be that for older people who are at risk for cognitive decline—such as those who present with speech in noise problems, word finding problems, an inability to make sense of conversational speech, memory problems—or perhaps based on a loved one’s concerns, a cognitive screening is appropriate. Of note, on many screeners “at risk” may potentially be indicated via non-normative results or “mild cognitive impairment” (MCI). Given either result, the patient should probably be referred to their MD for further investigation and management of the potential cognitive issue, and perhaps a trial with hearing aids or other devices and protocols would be in order.
Deal: That sounds reasonable with the caveat that organizations like the United States Preventive Services Task Force do not recommend screening for cognitive impairment in individuals without any symptoms, as this can potentially cause more harm than good. However, as we discussed earlier, our participants were carefully chosen to be in the ACHIEVE study. Although clinical trials give us good evidence for clinical decision-making, we need to remember, when making recommendations for individual patients, that our data represents only the people studied. I know you often say in your lectures and articles, group data only represents the average effect in the group. Individuals within that group may have more or less benefit, and our results may not always apply to others outside the group if they have very different characteristics. The question is, how similar is the patient before me to the group that showed benefit?
Beck: Exactly. The example I often use to make that point is that if you added all the males and females in the world together, we would have just over 8 billion people. As such, one might say of the entire population that the average number of ovaries per human is one; and although that is indeed truly the average, it is not reflective of any males in the population, and only very few females. The average for the group is a useful measure, but is not necessarily representative of a given individual.
Beck: And to be clear, the difference that you found within the “higher risk” ARIC group participants was that, over the three-year period, the people who did receive hearing aids had a 48% reduction in cognitive decline.
Deal: Exactly. For older patients (over age 70) already enrolled in the ARIC study, and who were already at higher risk for cognitive decline, the participants who received hearing aids had a 48% reduction in cognitive decline, as compared to those who received only health education. And again, this impressive benefit was not apparent for those in the de novo group, who were younger, had fewer risk factors for cardiovascular or cognitive decline, and had higher educational attainment and higher cognitive baselines. In summary, taking all the data and information and inferences together, hearing loss might be an important global health target for dementia prevention.
Beck: Yes, I think that is consistent with the literature on these matters and one must remember that although the group data has meaning and is informative and important, it tells us precious little about the specific patient in front of us. More research is indicated!
Beck: Thank you, Jennifer. I believe this interview will help many people get a better and deeper understanding of the ACHIEVE study. It is always a pleasure working with you.
Deal: Thanks, Doug. I’m glad we were able to dig deeper than just the headlines. This is important information and it’s complex, so the more we can talk about it and clarify what it says and what it means, the better.
Douglas L. Beck, AuD, F-AAA, CCC-A, is an audiologist and consultant who serves on the Hearing Review editorial advisory board as the senior editor of clinical research and writes for multiple audiology, science, medical, and health-related professional organizations globally. He retired as vice president of clinical sciences at Cognivue Inc in June 2023. To learn more: www.douglaslbeck.com