Methods – Auditory Research in Children with HIV: Cape Town

There were 129 children from ARCH: Cape Town with ABR data included.
There were 74 PHIV children (40 girls and 34 boys), 29 PHEU children (8 girls and 21 boys), and 26 HUU children (13 girls and 13 boys).
All children were assessed between 11-12 years of age.

The ABR procedure is a portion of a larger audiology protocol of the ARCH study, but only measures specific to the ABR data are reported here. A single audiologist (Elliott) collected all of the data and was blinded to HIV exposure status.
Otoscopy and tympanometry were performed to evaluate whether any outer or middle ear pathologies would affect the ABR research procedures.
Once electrode sites were prepared, surface electrodes were attached to the child’s high forehead, the right and left earlobes, and the center of the forehead (ground).
ABRs were obtained using rarefaction and condensation clicks through insert earphones at a rate of 11.1/sec and at 75 decibels (dB) normal hearing level (nHL).
Ipsilateral and contralateral tracings were obtained simultaneously.
Each child was instructed to remain as quiet as possible and that they did not need to respond while a minimum of 2000 clicks were presented. During the measures, the lights were dimmed, the child reclined on a cot, and most fell asleep.
ABRs were obtained in each ear and completed at least twice to ensure waveform repeatability.

ABR peak I, III, and V latencies and peak V amplitudes in each ear were identified. All latencies and amplitudes were determined independently, then reconciled between investigators (Torre and Elliott) when there were discrepancies.

ABR data from PHEU and HUU children were combined as the comparison group for all analyses.
Individual ABR peak latencies and peak V amplitude data of both ears were analyzed simultaneously between PHIV and combined PHEU/HUU groups using generalized estimation equation models (SAS, Version 9.4) with exchangeable working correlation and adjusting for age and sex.