Mosley, Thomas H.

AbstractBackgroundHearing loss is associated with greater cognitive decline and incident dementia. Whether hearing intervention could reduce cognitive decline in older adults with hearing loss is unknown.MethodThe ACHIEVE study is a randomized trial (NCT03243422) of 70‐84 year‐old adults with untreated hearing loss and free from substantial cognitive impairment that took place at four U.S. sites. Participants were recruited from two study populations: 1) a group of adults participating in a longstanding observational study of cardiovascular health (Atherosclerosis Risk in Communities [ARIC] study), and 2) a group of healthy de novo community volunteers. Participants were randomised (1:1) to hearing intervention (HI; audiological counseling and provision of hearing aids) or a successful aging health education control intervention (SA; sessions with a health educator on chronic disease prevention). The primary intention‐to‐treat endpoint was 3‐year change in a global cognition standardized factor score from a comprehensive neurocognitive battery.Result977 participants (238 ARIC, 739 de novo) underwent randomisation; 490 were assigned to HI and 487 to SA control. Participants from ARIC were older, had more risk factors for cognitive decline, and had lower baseline cognitive scores than the de novo group. In the primary analysis combining the ARIC and de novo groups, 3‐year cognitive change (in S.D. units) was not significantly different between HI and SA control (HI: ‐0·200 [95% CI: ‐0·256,‐0·144]; SA: ‐0·202 [‐0·258,‐0·145]; Difference 0·002 [‐0·077,0·081],p = 0·96). However, prespecified analyses demonstrated significant differences in the effect of HI on cognitive change between the ARIC and de novo group (p interaction = 0·010). In the ARIC group, HI was associated with a 48% reduction in 3‐year cognitive change compared to SA control (HI: ‐0·211 [‐0·349,‐0·073]; SA: ‐0·402 [‐0·536, ‐0·267]; Difference 0·191 [0·022,0·360,p = 0·027]). In the de novo group, cognitive change was not significantly different between HI and SA control (HI: ‐0·213 [‐0·277,‐0·148]; SA: ‐0·151 [‐0·215,‐0·087]; Difference ‐0·061 [‐0·151,0·028,p = 0·18]). The rate of cognitive change among control participants was observed to be 2.7‐fold faster in the ARIC versus de novo group.ConclusionHearing intervention may have a significant effect on reducing cognitive change over 3 years in populations of older adults at increased risk for cognitive decline.

AbstractBackgroundHearing loss is associated with cognitive decline and dementia. The ongoing ACHIEVE Study was the first randomized trial to test the effects of hearing treatment on three‐year cognitive change. The ACHIEVE – Brain Health Follow‐Up Study will extend follow‐up to six years post‐randomization to determine the long‐term and potentially nonlinear effects of hearing treatment vs. health education control with delayed treatment on dementia and cognitive decline.MethodsParticipants will be recruited from the 977 participants enrolled in the ACHIEVE Study. After Year 3, hearing intervention participants will continue to receive hearing care and the control group will be offered the hearing intervention. Co‐primary study outcomes will be cognitive decline and a composite of incident mild cognitive impairment (MCI)/probable dementia. Secondary outcomes include domain‐specific cognitive decline, brain structural changes on magnetic resonance imaging (MRI), and other functional outcomes (e.g., physical activity, social isolation). Power analyses for the co‐primary outcomes assumed an annual attrition rate of 10% and an immediate, lagged, or cumulative treatment effect.ResultsWhen comparing multi‐year cognitive decline (Table 1), in the scenario of a constant treatment effect that assumes a strong and immediate treatment effect, the benefit of extended follow‐up is not greater power, but additional information on the long‐term effects of hearing intervention. In a scenario of a lagged treatment effect, a two‐year lag in the treatment effect causes the Year 3 assessment to be severely underpowered (28%) but provides sufficient power (80%) at Year 6 despite attrition. In a scenario of a cumulative treatment effect that increases with time, analyses are similarly underpowered at Year 3 (65%) but not at Year 6 (82%). The same pattern is evident when estimating the power at Year 3 (57%) and Year 6 (80%) to detect incident MCI/probable dementia in a Cox regression model that assumes a protective hazard ratio of 0.70 (Figure 1).ConclusionAcross all non‐constant scenarios of potential treatment effect, six years of follow‐up increases precision and provides valuable information to better delineate long‐term cognitive trajectories. The ACHIEVE ‐ Brain Health Follow‐Up Study will be completed in 2025.