[Phenotype of frailty: the influence of each item in determining frailty in community-dwelling elderly - The Fibra Study].

The phenotype of frailty is used to assess frailty among the elderly by examining the following items: weight loss; exhaustion; low level of physical activity; weakness; and slow gait speed. The aim of the study was to evaluate the contribution of each item to determine the frailty syndrome among elderly Brazilians. The analysis was done using Multinomial Logistic Regression. The total sample of 5532 randomly selected elderly people in many cities in Brazil between December 2008 and September 2009 was assessed using the phenotype of frailty. The most frequent items were level of physical activity, followed by muscular weakness and slow gait speed. Items that were more likely to develop frailty, when positive, were slow gait speed (OR = 10.50, 95%CI 8.55 - 12.90, p <0.001) and muscular weakness (OR = 7.31, 95%CI 6,02 - 8,86, p <0.001). The final model with five items explained 99.6% of frailty in the sample. These results suggested that the level of physical activity, weakness and slow gait speed were the items that most influence the determination of frailty, however the application of all items of the phenotype of frailty is the best way to assess frailty.