“…A total of 51 frailty assessment instruments were analyzed in 96 studies published between 1997 and 2018. There were 82 studies published in English [18–99], 9 in Portuguese/BR [100–108], 3 in Japanese [109–111], 1 in Korean [112] and 1 in German [113]. The countries where the participants were most commonly sampled were the USA, with 14 studies [18, 21, 26, 49, 56, 61, 66, 70, 72, 77, 78, 86, 91, 95], Brazil, with 11 studies [64, 83, 92, 100–108], Canada, also with 11 studies [20, 22–24, 39, 54, 71, 80, 93, 94] and the Netherlands with 8 publications [28, 30, 32, 34, 36, 40, 55, 79, 96].…”