“…Studies were published between 1991 and 2014 (median year 2007) and were conducted in the United States ( n = 7), Canada (5), France (3), Italy (3), and Germany (2) and one each in Finland, New Zealand, and the United Kingdom. Most studies did not report on sources of funding ( n = 13), one specifically reported no funding [68], seven reported grant funding [13, 19, 62, 64, 66, 69, 75, 76], and two reported funding from industry [70, 75]. …”