Characteristics of the studies reviewed Eighty-three studies met the inclusion criteria above [11– 112]. Of these, 56 were conducted in the United States; 9 in other developed countries (Canada, Netherlands, Norway,
Characteristics of the studies reviewedEighty-three studies met the inclusion criteria above [11–112]. Of these, 56 were conducted in the United States; 9 inother developed countries (Canada, Netherlands, Norway,