“…All 23 studies included in the systematic review were in English. We identified 6 studies from the United States [40,45,47,48,54,55], 2 from Canada [44,55] and 10 from Europe, of which 5 were from the United Kingdom [41,43,50,56,57], 2 from Spain [36,38], 1 from Sweden [51], 1 from the Netherlands [58] and 1 from Italy [49]. There were also 3 articles from Asia, of which 2 were from China [42,59] and 1 from Singapore [60].…”