Bone-anchored hearing aids for people who are bilaterally deaf: a systematic review and economic evaluation

Abstract

The aim of this systematic review, using standard methodology,was to assess the clinical and cost-effectiveness of bone-anchored hearing aids (BAHAs) for people who are bilaterally deaf. Prospective studies comparing BAHAs versus conventional hearing aids [air conduction hearing aid (ACHA) or bone conduction hearing aid (BCHA)], unaided hearing or ear surgery; and unilateral versus bilateral BAHAs were eligible. Twelve clinical effectiveness studies were included. No eligible comparisons with ear surgery were identified. Overall quality was rated as weak for all included studies.

There appeared to be some audiological benefi ts of BAHAs compared with BCHAs and improvements in speech understanding in noise compared with ACHAs, however ACHAs may produce better audiological results for other outcomes; the limited evidence reduces certainty. Hearing is improved with BAHAs compared with unaided hearing. Improvements in QoL with BAHAs were identifi ed by a hearing-specifi c instrument but not generic QoL measures. Studies comparing unilateral with bilateral BAHAs suggested benefi ts of bilateral BAHAs in many, but not all, situations.

A decision analytic model was developed to estimate the costs and benefits of unilateral BAHAs over a ten year time horizon. The incremental cost per user receiving BAHA, compared with BCHA, was £16,344 for children and £13,281 for adults. In an exploratory analysis the incremental cost per QALY gained was between £118,898 and £55,424 for children and between £98,790 to £46,051 for adults for BAHAs compared with BCHA, depending on the assumed QoL gain and proportion of each modelled cohort using their hearing aid for eight or more hours per day. Deterministic sensitivity analysis suggested results were highly sensitive to the assumed proportion of people using BCHA for eight or more hours per day.

Exploratory cost effectiveness analysis suggests that BAHAs are unlikely to be a cost effective option where the benefi ts are similar for BAHAs and their comparators. The greater the benefit from aided hearing and the greater the difference in the proportion of people using the hearing aid for eight hours or more per day, the more likely BAHAs are to be a cost effective option. The inclusion of other dimensions of QoL may also increase the likelihood of BAHAs being a cost effective option.

A national audit of BAHAs is needed to provide clarity on the many areas of uncertainty surrounding BAHAs.