Table 1

Characteristics of the included evidence

Population characteristics across included studies
Total number of participants181 006
Age of participants18 and over
Breakdown of the population according to world region
  • Europe: 38% of participants

  • North America: 33% of participants

  • Asia (Japan and Asian Russia): 25% of participants

  • Australia: 5% of participants

Study characteristics
Baseline data collection years, range1965–1996
Length of follow-up, range3–21 years
Size, rangeBetween 98 and 47 713 subjects
  • All-male sample in nine papers21–29

  • All-female sample in six papers30–35

  • Mixed sample in eight papers36–43