Table 2 Recruitment survey rates: Wave 1.

	Canada	USA	UK	Australia
Number recruited	2507	2500	2730	2566
Cooperation rate	82.3%	83.2%	78.7%	78.8%
Response Rate AAPOR#4	49.5%	25.6%	37.8%	45.8%
Survey length (min)	11.8	13.2	10.3	9.1