We commend Mahmoudi et al1 for investigating the important topic of hearing aids and the association with a lower risk of dementia, depression, and falls. There are few proven interventions to delay dementia. If the association between hearing aids and dementia is proven to be causal, hearing loss could potentially be a modifiable risk factor to help prevent or delay dementia in older adults. Hearing aids are a notably high‐cost treatment for hearing loss, one factor that would make it difficult to execute a randomized controlled trial to answer this important research question. Thus, high‐quality observational studies are necessary and of the utmost importance to yield valid results. From the information provided in the original article, it is unclear when follow‐up began for the hearing aid and non–hearing aid groups. The authors reported follow‐up started at the time of the hearing loss diagnosis, but often there is a lag time from hearing loss diagnosis to acquisition of hearing aids. Requiring that persons survive until the receipt of a hearing aid introduces the concern of immortal time bias, or a selection of persons in the intervention arm who are healthier. It is uncertain how this was handled in the present study or how it would affect study results. Another concern we have is that the cohorts were restricted to persons with a full 3 years of follow‐up. We are concerned that this may introduce a survivorship and, more generally, a loss‐to‐follow‐up bias ...
Language: en
LA - en SN - 0002-8614 UR - http://dx.doi.org/10.1111/jgs.16367 ID - ref1 ER -