Background: Novel strategies are needed to assess frailty in the context of therapy decisions for older adults with acute myeloid leukemia (AML). Our objectives were to describe pre-treatment DAFI scores for older AML patients treated on clinical trials and explore their relationship with treatment outcomes. Methods: We conducted a exploratory analysis utilizing data from two clinical trials of adults aged ≥60 years with newly diagnosed AML (Alliance/CALGB 11001 [intensive therapy] and Alliance/CALGB 11002 [non-intensive therapy]). We included the subset of patients in each trial enrolled on geriatric assessment companion studies (Alliance/CALGB 361006, 361101). A DAFI score was calculated for each patient using 51 variables including demographic, geriatric assessment, and laboratory data derived from the geriatric assessment. Individuals with ≥90% items were included (consistent with other studies); DAFI scores ranged from 0 to 1 and were evaluated using established categories (0- <.2 [robust]; 0.2-<.35 [pre-frail]; 0.35+ [frail]) and as a continuous score. Associations between DAFI scores and toxicity and overall survival (OS) were evaluated with Fisher’s exact-testing and Kaplan Meier/cox proportional hazards, respectively. Results: The median age was 68 years (range 61, 82) and 72 years (range 61, 92) for those getting intensive (N=31) and less intensive therapy (N= 75), respectively. Individuals in the intensive study had a median pre-treatment DAFI score of 0.15 (range 0.05, 0.31) and were all categorized as robust (75%) or pre-frail (25%). There was no significant difference in median OS (14.6 vs. 14.7 months) or non-hematological grade 3+ adverse events (AEs; 85% vs. 89%) between robust vs. pre-frail individuals in this trial, respectively. However, pre-frail adults experienced a trend towards greater grade 4 non-hematological toxicity than robust individuals (67% vs 26%, p=0.05). In the non-intensive trial, the median DAFI score was 0.24 (range 0.04, 0.48) and most individuals were pre-frail (49.3%) or frail (17.3%). Non-hematologic grade 3+ AEs did not vary by DAFI group, 88% robust, 95% pre-frail, and 77% frail (p=0.15). Median OS was 7.4, 10.8, and 6.3 months for robust, pre-frail, and frail respectively (p=0.17). Adjusting for age, each 0.1 increase in DAFI score was associated with increased mortality hazard (HR 1.8, 95% CI 1.0-3.2). Conclusions: DAFI score calculation provides a potential novel strategy for categorization of frailty in AML. In our assessment, higher DAFI scores were associated with toxicity during intensive induction and mortality in the less intensive setting. This method should be studied in larger samples randomized by treatment intensity. Support: UG1CA189823; Bayer Healthcare/Berlex (CALGB 11001); NCT01253070 (CALGB 11001). Clinical trial information: NCT01253070, NCT01420926.