Is measured hearing aid benefit affected by seeing baseline outcome questionnaire responses?

Purpose To determine whether hearing aid outcome measured by the Hearing Handicap Inventory (HHI) for the Elderly/Adults (Newman, Weinstein, Jacobson, & Hug, 1990; Ventry & Weinstein, 1982) is differentially affected by informed vs. blind administration of the postfitting questionnaire. Method Participants completed the HHI at their hearing aid evaluation and again at their hearing aid follow-up visit. At follow-up, half received a clean HHI form (blind administration), whereas the remainder responded on their original form (informed administration) and could thus base their follow-up responses on those they gave at the hearing aid evaluation. Results The data show that for the population examined here, informed administration of the follow-up HHI did not yield a different outcome to blind administration of the follow-up HHI. This was not influenced by past hearing aid use, age of the participant, or the duration of time between baseline questionnaire completion and follow-up completion. Conclusion These data suggest that completion of follow-up questionnaires in either informed or blind format will have little impact on HHI responses, most likely because of the many other factors that combined to influence hearing aid outcome.