Insert Table 1 about here.
The majority (n=12, 70.6%) of studies were published in the last seven
years (2012-2018) (25, 26, 28, 30-32, 34-38, 40) and the remaining
studies (n=5, 29.4%) were published more than ten years ago (1990-2007)
(24, 27, 29, 33, 39). Fifteen studies were published as journal
articles, and two were conference abstracts. Four studies originated in
the United States, three each from Spain and South Korea, two from each
of the following countries, Canada, and Japan, and one each from South
Africa, Germany, and Italy. The mean sample size (standard deviation)
was 38.1 (34.9) subjects.