Design and methods of the Second Australian Study of Health and Relationships.

Background: This paper describes the methods and process of the Second Australian Study of Health and Relationships. Methods: A representative sample of the Australian population was contacted by landline and mobile phone modified random-digit dialling in 2012-13. Computer-assisted telephone interviews elicited sociodemographic and health details as well as sexual behaviour and attitudes. For analysis, the sample was weighted to reflect the study design and further weighted to reflect the location, age and sex distribution of the population at the 2011 Census. Results: Interviews were completed with 9963 men and 10 131 women aged 16-69 years from all states and territories. The overall participation rate among eligible people was 66.2% (63.9% for landline men, 67.9% for landline women and 66.5% for mobile respondents). Accounting for the survey design and adjusting to match the 2011 Census resulted in a weighted sample of 20 094 people (10 056 men and 10 038 women). The sample was broadly representative of the Australian population, although as in most surveys, people with higher education and higher status occupations were overrepresented. Data quality was high, with the great majority saying they were not at all or only slightly embarrassed by the questionnaire and almost all saying they were 90-100% honest in their answers. Conclusions: The combination of methods and design in the Second Australian Study of Health and Relationships, together with the high participation rate, strongly suggests that the results of the study are robust and broadly representative of the Australian population. [ABSTRACT FROM AUTHOR]