Characteristics of the study sample.^*

*Countries included in the analysis: Austria, Azerbaijan, Belarus, Belgium, Belize, Brazil, Bulgaria, Canada, Chile, Colombia, Costa Rica, Cuba, Denmark, El Salvador, Finland, France, Germany, Guatemala, Hungary, Ireland, Israel, Italy, Kazakhstan, Kuwait, Kyrgyzstan, Luxembourg, Mexico, Netherlands, Norway, Panama, Republic of Korea, Romania, Russian Federation, Spain, Sweden, Switzerland, TFYR Macedonia, Turkmenistan, Ukraine, United Kingdom, United States of America, Uruguay, Uzbekistan, and Venezuela.