RESUMEN
BACKGROUND: The early identification of individuals at high risk for adverse outcomes by a Comprehensive Geriatric Assessment (CGA) in resource-limited primary care settings enables tailored treatments, however, the evidence concerning its benefits are still controversial. The main objective of this study was to examine the validity and reliability of the "Multidimensional Assessment of Older People in Primary Care (AMPI-AB)", a CGA for primary care in resource-limited settings. METHODS: Longitudinal study, with median follow-up time of 16 months. Older adults from a public primary care unit in São Paulo, Brazil, were consecutively admitted. Reliability was tested in a sample from a public geriatric outpatient clinic. Participants were classified by the AMPI-AB score as requiring a low, intermediate or high complexity of care. The Physical Frailty Phenotype was used to explore the AMPI-AB's concurrent validity. Predictive validity was assessed with mortality, worsening of the functional status, hospitalizations, emergency room (ER) visits and falls. The area under the ROC curve and logistic regression were calculated for binary outcomes, and a Cox proportional hazards model was used for survival analysis. RESULTS: Older adults (n = 317) with a median age of 80 (74-86) years, 67% female, were consecutively admitted. At the follow-up, 7.1% of participants had died, and increased dependency on basic and instrumental activities of daily living was detected in 8.9 and 41.1% of the participants, respectively. The AMPI-AB score was accurate in detecting frailty (area under the ROC curve = 0.851), predicted mortality (HR = 1.25, 95%CI = 1.13-1.39) and increased dependency on basic (OR = 1.26, 95%CI = 1.10-1.46) and instrumental (OR = 1.22, 95%CI = 1.12-1.34) activities of daily living, hospitalizations (OR = 2.05, 95%CI = 1.04-1.26), ER visits (OR = 1.20, 95%CI = 1.10-1.31) and falls (OR = 1.10, 95%CI = 1.01-1.20), all models adjusted for sex and years of schooling. Reliability was tested in a sample of 52 older adults with a median age of 72 (85-64) years, 63.5% female. The AMPI-AB also had good interrater (ICC = 0.87, 95%CI = 0.78-0.92), test-retest (ICC = 0.86, 95%CI = 0.76-0.93) and proxy reliability (ICC = 0.84, 95%CI = 0.67-0.93). The Cronbach's alpha was 0.69, and the mean AMPI-AB administration time was 05:44 ± 02:42 min. CONCLUSION: The AMPI-AB is a valid and reliable tool for managing older adults in resource-limited primary care settings.