Function and disability in late life: comparison of the Late-Life Function and Disability Instrument to the Short-Form-36 and the London Handicap Scale.
OBJECTIVE
We evaluated the Late-Life Function and Disability Instrument's (LLFDI) concurrent validity, comprehensiveness and precision by comparing it with the Short-Form-36 physical functioning (PF-10) and the London Handicap Scale (LHS).


METHODS
We administered the LLFDI, PF-10 and LHS to 75 community-dwelling adults (> 60 years of age). We used Pearson correlation coefficients to examine concurrent validity and Rasch analysis to compare the item hierarchies, content ranges and precision of the PF-10 and LLFDI function domains, and the LHS and the LLFDI disability domains.


RESULTS
LLFDI Function (lower extremity scales) and PF-10 scores were highly correlated (r = 0.74 - 0.86, p > 0.001); moderate correlations were found between the LHS and the LLFDI Disability limitation (r = 0.66, p < 0.0001) and Disability frequency (r = 0.47, p < 0.001) scores. The LLFDI had a wider range of content coverage, less ceiling effects and better relative precision across the spectrum of function and disability than the PF-10 and the LHS. The LHS had slightly more content range and precision in the lower end of the disability scale than the LLFDI.


CONCLUSIONS
The LLFDI is a more comprehensive and precise instrument compared to the PF-10 and LHS for assessing function and disability in community-dwelling older adults.
Dubuc
Nicole
N
Center for Rehabilitation Effectiveness, Sargent College of Health and Rehabilitation Sciences, Boston University, MA 02215, USA.
Haley
Stephen
S
Ni
Pengsheng
P
Kooyoomjian
Jill
J
Jette
Alan
A
D000203:Activities of Daily Living; D000222:Adaptation, Physiological; D000223:Adaptation, Psychological; D000368:Aged; D000369:Aged, 80 and over; D004185:Disability Evaluation; D006233:Persons with Disabilities; D005260:Female; D015577:Geriatric Assessment; D006801:Humans; D008297:Male; D008875:Middle Aged; D011788:Quality of Life; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D018434:Sickness Impact Profile; D012959:Socioeconomic Factors; D006113:United Kingdom; D014481:United States