Table 1

Age and sex of those approached to take part in the studya

Responders
CharacteristicNon-respondersAgreed to contactDeclined contactAgreed to take part in telephone interview about reasons for decliningb
Mean age, years, (SD)46.0 (13.2) n = 580948.2 (13.5) n = 274754.2 (12.9) n = 156553.5 (13.2) n = 427
Female sex, n (%)4040 (67.7) n = 59672012 (71.7) n = 28071125 (69.8) n = 1612334 (74.9) n = 446

  • SD = standard deviation.

  • ↵a Data on age and sex were not available for all.

  • ↵b Subset of all those who declined (column 4).