Attrition in Cochlear Implant Research: Sociodemographic, Audiologic, and Performance Variables

To understand the sociodemographic, audiologic, and performance variables that influence participant attrition in long-term, repeated-measures clinical research.

A retrospective review was completed for adult cochlear implant (CI) recipients who enrolled in an ongoing, repeated-measures clinical research study investigating outcomes between two mapping procedures. The sample was stratified into those who completed the 12-month study and those who withdrew prior to the study endpoint. The groups were compared for sociodemographic variables (age at consent, race, ethnicity, biological sex, drive time to the clinic, socioeconomic position, and rurality), cognition, and audiologic variables (device type, ipsilateral and contralateral hearing, device wear-time, and tonotopic mismatch). Early performance on CNC word recognition was analyzed between groups.

Of the 118 research participants, the attrition rate for the sample was 21%. Sociodemographic variables were at parity between the completed and withdrawal groups. Of the reviewed audiologic variables, the withdrawal group had poorer low-frequency acoustic hearing thresholds, was less likely to be electric-acoustic stimulation users than CI alone users (likely due to unaided thresholds), and had greater tonotopic mismatch. Early CNC word recognition was significantly different between the two groups, with the completed group having better early performance than the withdrawal group.

The present findings serve as a reminder of the need for reflection on clinical research study attrition patterns and a call for intentionally designed study inclusion criteria and procedures to support enrollment and retention of a representative sample.