Late-Life Function & Disability Instrument
What It Measures
The LLFDI separates two things that usually get bundled together. Function is whether a person can physically do a task — climb stairs, carry groceries, reach overhead. Disability is whether they actually take part in the life roles those tasks serve — visiting friends, keeping up a home, taking care of others.
The 32-item function component asks how much difficulty a person has, across upper extremity, basic lower extremity, and advanced lower extremity tasks. The 16-item disability component asks two questions about each major life activity: how often do you do it, and how limited do you feel doing it. Frequency splits into personal and social roles; limitation splits into instrumental and management roles.
Further Reading
Additional Notes
Licensing Notes: The manual is posted freely by Boston University School of Public Health, and the instrument circulates without a posted fee.
Learn More: The two components are often used separately, and a systematic review found the basic lower extremity subscale and the overall function summary score carried the strongest effect sizes, alongside the disability limitation dimension. A minimal clinically important difference of about 2 points has been reported for small change on the function component. A computer-adaptive version, the LLFDI-CAT, also exists.
