DEVELOPMENT AND VALIDATION OF THE LOWER LIMB DISABILITY QUESTIONNAIRE (LLDQ) REGIONAL OUTCOME TOOL. Anne Neller; Philip Gabel*; Brendan Burkett Health Science, Uni Sunshine Coast, Coolum , QLD, Australia PURPOSE: The purpose of this research was to develop and validate a new regional outcome measure for the lower limb. BACKGROUNDS/SIGNIFICANCE: There is currently only one published regional outcome measure for the lower limb, the Lower Extremity Functional Score (LEFS). This existing tool is criticized for poor clinical utility through administration, scoring and completion time and through poor methodological characteristics including item redundancy, missing data and error range. A new tool, the Lower Limb Disability Questionnaire (LLDQ) was developed to overcome these attributes. SUBJECTS: Patients (n = 127) from six separate Australian physiotherapy primary contact outpatient clinics were recruited from a population sample of convenience with inclusion criteria of presenting cause being lower extremity symptoms. Exclusion criteria were a minimum age of 13 and non-comprehension of the English language. METHODS AND MATERIALS: The LLDQ and LEFS tools were investigated through direct head-to-head comparison. This provided methodological and practical characteristics for the full sample of 225 responses. Prospective repeated measure were used on two subgroups to provide test-retest reliability (n = 38) with 76 responses and responsiveness with change score values (n = 41) with 82 responses. Population demographics were assessed for age, gender, occupation area employer type, marital status dominance and condition duration. ANALYSES: A MS-Excel with stats-pack and SPSS statistical programs were used for analysis. Mean, median and standard deviation of responses for each tool were determined including individual item response and demographical data. Pearsons ICC r value was used to determine test-retest reliability and criterion validity (p = 0.05). Other methodological characteristics assessed were construct validity through score range and distribution, error range and responsiveness through uses of known group difference and Internal Consistency using Cronbachs Alpha. RESULTS: The LLDQ demonstrated test-retest reliability (r = 0.98) and internal consistency (0.91) with face, content and construct validity shown through the development methodology. The head-to-head comparison demonstrated criterion validity (r = 0.89) with the LEFS, construct validity was also validated using the known group method and from the distribution range of 0-98%. The psychometric values were determined for error range, using Standard Error of the Measurement (SEM = 2.75%) and Minimum Detectable Change (MDC90 = 6.41%) and responsiveness through Standardized Response Mean (SRM = 2.03). These show a preference for the LLDQ over the LEFS without a tendency toward item redundancy. The LLDQs practical clinical characteristics demonstrated shorter completion and scoring times with lower user response error and no missing or absent data responses. CONCLUSIONS: This study, though lacking sample population diversity, demonstrated the potential for the LLDQ as a viable regional outcome measure of the lower extremity in a clinical setting. The preferred utility, practical characteristics and sound measurement properties indicate the LLDQ as the preferred regional outcome tool over the LEFS for assessment of lower extremity disability. Further formal investigation on a significant diversely recruited population sample and comparison to condition specific tools is warranted. FUNDING SOURCE: Support: University of the Sunshine Coast (USC) Postgraduate Doctoral School. Material Gain - none KEYWORDS: Evaluation, Lower extremity, Questionnaire, Functional Status, Outcome Table Comparison of Properties of the LLDQ and LEFS Copyright 2009 by the American Physical Therapy Association. Requests for reprints should be directed to the corresponding author of the article. Educators, students, and other academic customers may receive permission to reprint copyrighted material from Physical Therapy (ISSN 1538-6724) by contacting the Copyright Clearance Center Inc, 222 Rosewood Dr, Danvers, MA 01923. Other types of customers who want permission to reprint should contact the APTA Editorial Office, Attn: Physical Therapy.