Measuring satisfaction with amplification in daily life: The SADL scale

Objective: To develop a self-report inventory to quantify satisfaction with hearing aids. Design: The inventory was developed in several stages. To determine the elements that are most important to satisfaction for most people, we conducted structured interviews and then designed a questionnaire. Hearing aid owners responded to the questionnaire, indicating the relative importance of 14 different elements in their hearing aid satisfaction. Analyses indicated that the elements could be placed into four importance content areas. Trial satisfaction items were designed for each content area and submitted to focus groups to identify highly salient items as well as ambiguous items. A 25-item satisfaction questionnaire then was developed and disseminated to hearing aid owners. Results were obtained from 257 individuals. These data were analyzed to generate the final questionnaire. Results: Fifteen items, divided into four subscales, were selected for the final Satisfaction with Amplification in Daily Life (SADL) questionnaire. The questionnaire yields a Global satisfaction score and a profile of subscale scores, which address Positive Effects, Service and Cost, Negative Features, and Personal Image. A preliminary evaluation of retest stability was conducted with 104 subjects. Ninety percent critical differences for the various scores ranged from 0.9 to 2.0 score intervals on a 7 point scale. Conclusions: The SADL scale is both brief enough to be clinically acceptable and comprehensive enough to provide a valid assessment of an inherently multidimensional variable. Additional assessment is necessary to refine understanding of its test-retest properties, explore validity issues, and determine clinical, research, and administrative applications of the data.