The selection of appropriate outcome measures is important in evaluating specialized geriatric programs, but how the various measures compare, and which are most appropriate, are matters still largely unexplored. We compared several outcome measures, including goal attainment scaling, to assess their sensitivity to changes in the health status of frail elderly patients admitted to two geriatric medicine wards. GAS is a measurement approach which accommodates multiple individual patient goals, and has a scoring system which allows for comparisons between patients. Forty-five patients (mean age 81 years, 30 females) received comprehensive assessments. GAS yielded a mean 5 goals per patient. The mean gain in the GAS score was 22 points (SD = 7) which was compared with the change in the Barthel Index (r = 0.59), the Functional Independence Measure (r = 0.45), the Physical Self-Maintenance Scale (r = 0.54), the Katz Activities of Daily Living Index (r = 0.49) and the Spitzer Quality of Life Index (r = 0.38). The inter-rater reliability of scoring the GAS follow-up guides was 0.91. Using a relative efficiency statistic, GAS proved more efficient than any other measure. The effect size statistic also demonstrated an increased responsiveness to change of GAS compared with standard measures. GAS is an individualized measurement approach which shows promise as a responsive measure in frail elderly patients.