Measuring disability-specific patient benefit in cochlear implant programs: developing a short form of the Glasgow...

As healthcare resources are limited, evidence of program effectiveness is necessary. To demonstrate this, measurement should be conducted at the specific illness level, the generic health status level, and the utility level. Instruments need to be parsimonious to avoid cognitive overload, response burden, or participation refusal. Critical analysis of the Glasgow Hearing Status Inventory (GHSI) suggested that several items were redundant and the instrument could be shortened. We administered the GHSI and Assessment of Quality of Life (AQoL) instruments to 148 deafened adults with cochlear implants (CIs) and to 54 without CIs, as part of a cross-sectional study. We used standard psychometric procedures to examine the GHSI's structure, resulting in the removal of half of the items. The short version of the GHSI we labeled the Hearing Participation Scale (HPS), to avoid confusion with the GHSI. The HPS is an 11-item instrument measuring self-esteem, social handicap, and hearing handicap. Factor analysis suggested that each subscale was unidimensional. All items loaded on the principal component. Correlation with the GHSI was 0.95, suggesting that the two instruments could be used interchangeably. Both the HPS and the GHSI pro-vided evidence of monotonicity when used to predict AQoL scores. They were equally sensitive at differentiating between implantees and non-implantees. Although these findings need to be confirmed, the HPS is ready to be used in studies of interventions for deafness. At a time when evaluators are being asked for evidence of program effect, the parsimonious HPS achieves similar results to the GHS but requires half the items.