“…2). The number of studies assessing implementation outcome measures has increased over time, with one study published in 1998 [79], through to eight studies published in 2018/2019 [27,42,45,49,56,62,76,77]. Studies were predominantly conducted in high-income countries, with the majority conducted in the USA alone (n = 22) [25, 29, 30, 35, 37-39, 44, 46, 47, 53, 57, 58, 64, 66, 67].…”