An Application of the Medical Research Council's Guidelines for Evaluating Complex Interventions: A Usability Study Assessing Smartphone-Connected Listening Devices in Adults With Hearing Loss.

Purpose: The purpose of this study is to provide an example of the Medical Research Council's guidelines for evaluating complex health care interventions in the context of smartphone-connected listening devices in adults with hearing loss.

Method: Twenty existing hearing aid users trialed 1 of the following smartphone-connected listening devices: made-for-smartphone hearing aids, a personal sound amplification product, and a smartphone "hearing aid" application used with either wireless or wired earphones. Following 2 weeks of use in their everyday lives, participants completed self-report outcome measures.

Results: Relative to conventional hearing aids, self-reported use, benefit, and satisfaction were higher, and residual disability was lower for made-for-smartphone hearing aids. The converse was found for the other smartphone-connected listening devices trialed. Similarly, overall usability was judged to be "above average" for the made-for-smartphone hearing aids, but "below average" for the remaining devices.

Conclusions: This developmental work, guided by the Medical Research Council's framework, lays the foundation for feasibility and pilot studies, leading to high-quality research assessing the effectiveness of smartphone-connected listening devices. This future evidence is necessary to guide health care commissioners and policymakers when considering new service delivery models for adults living with hearing loss.