225774 Development and psychometric properties of a “function-neutral” measure of health-related quality of life

Wednesday, November 10, 2010 : 8:48 AM - 9:06 AM

Willi Horner-Johnson, PhD , Center on Community Accessibility, Oregon Health & Science University, Portland, OR
Gloria L. Krahn, PhD, MPH , National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta, GA
Trevor Hall, PsyD , Oregon Health & Science University, Portland, OR
Elena Andresen, PhD , Department of Epidemiology, University of Florida, Gainesville, FL
Jana J. Peterson, MPH, PhD , UMKC Institute for Human Development (UCEDD), University of Missouri - Kansas City, Kansas City, MO
Gale Roid, PhD , Warner Pacific College, Portland, OR
RRTC Expert Panel on Health Measurement , Rehabilitation Research and Training Center: Health and Wellness, Oregon Health & Science University, Portland, OR
Background: Measures of health-related quality of life (HRQOL) often include assessment of functional abilities, resulting in lower HRQOL scores for people with functional limitations. The conceptual confusion of health and function limits the usefulness of many HRQOL measures with persons with pre-existing functional limitations or disabilities. This presentation will describe a new generic measure of HRQOL that is designed to be function-neutral. Methods: Investigators developed an item pool from previous measures. Items were screened by an expert panel for 'essentialness' to measuring HRQOL, and for functional bias. Remaining items underwent phases of: 1) cognitive testing; 2) bias testing using differential item functioning (DIF) analyses; and 3) field testing with a large national sample. Phase three data were subjected to factor analysis, IRT analysis, item-total correlations within domains (physical, mental, social, spiritual), and DIF analyses for gender, racial, and ethnic bias. Results were reviewed by an expert panel to select the best-performing items among those with similar content. The selected items were then administered twice to a sample of 100 individuals to assess test-retest reliability. Results: Analyses of phase three data indicated high internal consistency (>0.90) of domain scales, excellent fit to an IRT model, and few items showing bias. Elimination of problematic and redundant items resulted in a 41-item scale. Test-retest correlations were ≥ 0.85, indicating good short-term stability. Conclusions: The function-neutral health-related quality of life measure demonstrates strong psychometric properties and little bias. It can be used with the general population as well as groups with functional limitations.

Learning Areas:
Public health or related research
Social and behavioral sciences

Learning Objectives:
1. Explain the need for a function-neutral measure of HRQOL 2. List the steps taken to reduce functional bias in the new measure 3. Describe the characteristics of the new measure

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: I am the PI of the study on which I will be presenting.
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.