Healthy HeaAring for Healthy Ageing: Data-driven Hearing Rehabilitation Intervention to Promote Healthy Hearing

The goal of the HAHA trial is to prove that the treatment of HI and prevention of HI-related cognitive decline are most likely to be effective if HI is approached as a broader neurodegenerative entity with multifaceted manifestations currently unaddressed in clinical practice and managed using a novel individualised data-driven protocol for early hearing rehabilitation. The main hypothesis is that, compared with standard care, the data-driven rehabilitation will likely have broader benefits manifested in three key areas: hearing, cognition, and quality of life and psychosocial outcomes.

Participants will be randomized 1:1 to either intervention (individualised data-driven hearing rehabilitation) or control group (standard care hearing rehabilitation). The primary objective of this study is to investigate the effect of an optimized data-driven hearing rehabilitation protocol versus standard care protocol on change in speech perception in noise (SPIN) in older adults with mild to moderately severe sensorineural HI and without dementia.

Hearing impairment (HI) is a major public health problem. HI has also been identified as a significant potentially modifiable risk factor for dementia. Thus, hearing rehabilitation may contribute to dementia risk reduction, although a causal HI-dementia relation is not fully established.

The HAHA trial will test an individualised, data-driven hearing rehabilitation protocol based on the ongoing BREM (Benefits of Real-Ear Measurement) study at KUH (clinicaltrials.gov ID NCT05621798). HAHA will use a pragmatic approach incorporated into routine specialized care (Hearing Center at the Dept of Otorhinolaryngology of KUH), to facilitate optimisation of the current HI clinical pathway and treatment process. This study is a proof-of-concept, single-site, 2-arm parallel group 12-month randomized controlled trial with a 12-month extended follow-up.

The investigators will recruite 200 participants referred to the Kuopio University Hospital Hearing Center from primary care that are aged 65 to 84 years with mild to moderately severe sensorineural HI and are about to receive their first HAs.

The intervention group will receive individually fitted HAs based on preliminary results from the ongoing BREM study at KUH to ensure adequate amplification, with immediate SPIN-based benefit validation. HA selection and individual tailoring will also be based on hearing questionnaires data. Participants are invited to intervention-related monitoring appointments at 3, 6 and 12 months after the primary HA fitting.

The control group will receive the same HAs fitted according to the standard care protocol. Standard care follow-up includes a phone call check 3 months after the primary fitting. Additional monitoring/re-fitting may be offered based on the participant's feedback and hearing rehabilitator's clinical judgement.

A range of auditory, cognitive, quality of life and psychosocial measures as well as exploratory measures such as EEG, MRI and vision-related measures are assessed at 12-month and 24-month visits on both groups. These assessments are included to investigate potential mechanisms underlying associations between HI, hearing rehabilitation, vision and cognition. The overall duration of the this trial is 2 years.

Eligibility Criteria:
Inclusion Criteria:

* Mild to moderately severe sensorineural HI (PTA (0,5-4kHz) between 20-64 dB (HL), as per Global Burden of Disease Expert Group on Hearing loss criteria)
* Community-dwelling, i.e. living at home / not living in a care home or nursing home
* Proficiency in Finnish language
* First-time hearing aid user

Exclusion Criteria:

* Conductive hearing loss (air-bone gap more than 20 dB HL in two consecutive frequencies)
* Difference between hearing levels of the ears is more than 15dB (HL) in three consecutive frequencies
* Hearing aid contraindication
* Previously diagnosed dementia, or current use of cholinesterase inhibitors and/or memantine. If there is a current ongoing diagnostic process for suspected dementia, the decision on eligibility will be made by an experienced study physician based on medical records and clinical judgement.
* Any health conditions severely impairing vision, mobility, communication, and/or ability to participate in study visits and complete study assessments, as judged by the study nurse and/or physician.