Outcomes
Primary outcome
The primary outcome was any of the following after 12 weeks of hearing aid use: 1) improving attention or memory scores on the NEUPSILIN; or 2) reducing latency of auditory evoked potentials, as measured by HEARLabĀ® equipment. This variable was dichotomized into two categories: improved (1) and not improved (0).
Improvement in the NEUPSILIN scores was defined as a reduction (in seconds) in reverse counting time and/or higher total score on the tasks of digit sequence repetition, working memory, auditory word span, immediate and delayed recall, recognition, long-term memory evocation, and visual memory. Improvement in auditory evoked potentials was defined as a decrease in latency time > 1 millisecond.
Secondary outcomes
We considered the total score of IOI-HA as a secondary outcome, which meant the overall satisfaction with the hearing aids. This variable was analyzed as an ordinal one.
After the trial started, we included the total score of IOI-HA as a secondary outcome so that we could assess self-satisfaction with regards to hearing aid use at the end of the research.