The study population were members of Life in AustraliaTM, Australia’s first and only probability-based online panel . The panel was established by the Social Research Centre in 2016 and is the most methodologically rigorous online panel in Australia. It exclusively uses random probability-based sampling methods and covers both online and offline population. Members of the panel are Australian residents aged 18 years or over who were randomly recruited via their landline or mobile telephone (rather than being self-selected volunteers) and consented to provide their contact details to take part in surveys on a regular basis . Participants receive a $10 to $15 reward for completing each monthly survey. Results from Life in AustraliaTM surveys are generalisable to the Australian population (see Appendix 1). All active members between the ages of 18 and 45 years were eligible to participate.
All eligible panel members were made aware of the opportunity to complete a survey about fertility and childbearing through the Social Research Centre’s regular communication. The survey was administered by the Social Research Centre. The methodology employed was a mixed-mode approach, using primarily online surveys supplemented with telephone surveys to include both the online and offline populations. Data collection was conducted from 18 February to 4 March 2019.
The study-specific questionnaire was developed by the authors of the paper who have extensive clinical and research experience in the fields of reproductive health (nursing and midwifery) and health promotion (public education program management). It included questions about socio-demographic circumstances (age, country of birth, residential postcode, relationship status, and parenthood status); current health behaviours (smoking status, alcohol consumption, recreational drug use, exercise regularity, health status of diet, and weight [underweight, normal weight, a bit overweight, quite overweight]); parenthood aspirations (‘Do you want (more) biological children in the future’ and ‘How many children would you like to have’); likelihood of changing health behaviour in preparation for pregnancy rated on a 4-point Likert scale ranging from ‘Very Likely’ to ‘Not at all likely’ (take a multi vitamin [females only], eat healthier, see a GP for a health check-up, reduce alcohol consumption [drinkers only], stop smoking [smokers only] and lose some weight [only people who rated themselves as a bit or quite overweight]). Attitudes towards being asked about pregnancy intention were gauged with the question ‘How would you feel if your GP asked you 'Would you (or your partner) like to become pregnant in the next year?’ where the response alternatives were ‘I wouldn’t mind’, ‘I would feel that it was inappropriate’, ‘I would appreciate it’, and ‘I would feel some other way’.
To correct for differences between the study population and the general population of people of reproductive age in Australia, and ensure the sample most closely represents the relevant Australian adult population, results were weighted to population benchmarks (see Appendix 1).
For the purpose of comparing levels of socio-economic advantage and disadvantage, respondents were assigned to quintiles based upon their residential postcode using the Index of Relative Socio-economic Disadvantage (IRSD). The IRSD is one of four indexes of socio-economic status developed by the Australian Bureau of Statistics (ABS) using information from their five-yearly Census. It distributes the population into five even quintiles denoting varying levels of disadvantage. A lower score (Quintile 1) indicates relatively greater disadvantage in general (e.g. more likely to include low income households, people with no qualifications, in low skill occupations). A high score (Quintile 5) indicates a relative lack of disadvantage in general.
Data were analysed in SPSS V25 using descriptive statistics. Gender and age group comparisons were made using Chi-square statistics and p-values <0.05 were considered significant.