Multiple sampling and recruitment strategies were used in this study to obtain a sample from the target population: all nurses and GPs working in the PHC setting of regional and rural Victoria. The two groups are discussed separately.
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4.2.1 Primary Health Care Nurses
The first target population of interest consisted of all nurses currently registered with theNursing and Midwifery Board of Australia (NMBA) who work in the PHC setting of regional and rural Victoria. This group comprises enrolled nurses, registered nurses and nurse practitioners who work in general practice, community health service, education and sexual health clinics. While there are no accurate data available on the number of nurses, a 2012 report estimated that of the 2,425 practice nurses working in Victoria, approximately 45 percent (1,090) are employed outside major cities (Australian Medicare Local Alliance 2012).
The absence of a sampling frame required convenience sampling, a non- probability sampling technique whereby participants are selected in the most convenient way (Blair & Blair 2015). This technique has shown to be fast, easy and economical (Babbie 2010). The sample generated with convenience sampling, however, is vulnerable to selection bias (Babbie 2010). It can lead to an under-representation of certain groups within the sample, like those who are not in contact with any of the recruiting organisations or have no Internet access (Bethlehem 2010). Further, just as in probability sampling approaches,
participation bias is an issue, because it is up to potential respondents to decide if they want to participate (Bethlehem 2010). Although this self-selection factor cannot be influenced, the choice to approach a broad and diverse group of organisations can reduce under-coverage (Bethlehem 2010). Overall, however, it cannot be assured that the sample obtained in this way will be a representation of the target population (Babbie 2010).
For non-probability samples, it is not possible to pre-assign a sample size or to obtain a random sample (Blair & Blair 2015). Consequently, an informal approach needs to be considered to yield a representative cross-section of the target group. One often-used method to obtain a sample size estimate is the use of a sample number that is typical for similar research in the field (Blair & Blair 2015). Research showed sample sizes in similar Australian studies ranged from 100 to 300; however, because of the contentious subject, lower responses were
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to be expected (Australian General Practice Network 2009; Joyce & Piterman 2011; Merrick et al. 2012). To recruit the PHCN participants, the study used a multifaceted approach, consisting of convenience sampling and snowball sampling techniques (Babbie 2010).
For the convenience sampling method, a total of 27 professional nursing organisations, regional Primary Health networks and women’s health services, as well as a range of other key organisations with a focus on regional health, were approached as they were identified as suitable sources for nurse recruitment. Additionally, a publically accessible Facebook page, named ‘Medication abortion access in regional Victoria’, was established to promote the study. Facebook is known to be an effective recruitment tool as it enables organisations to “share” and “like” the page (Kapp, Peters & Oliver 2013). A convenience sample was also obtained from the publicly accessible National Health Services Directory (NHSD 2017), an online joint initiative of Australia’s federal government and the
governments of all states and territories, which allowed potential participants to be approached directly instead of via third parties. The directory was explored for regional and rural general and primary care practices with a specific interest in sexual or women’s health and who employed practice nurses. To increase the chance of recruiting nurses, GP practice selection was restricted to relatively large (consisting of, approximately, more than six GPs) practices, as they appear to employ relatively more nurses. This search resulted in a list of 164 practices.
Eighteen of the 27 approached organisations promoted the study on their website, in their newsletter, mail-outs or on social media. Over the next four months, ongoing contact with the organisations that agreed to promote the study resulted in up to three published reminders and/or re-invitations to
participate. The Facebook page included a short invitation letter, pinned to the top of the page, and an embedded link to the online questionnaire. To increase page engagement, the content of the page was updated on a regular base, for example with reminders and encouragements.
The PHCNs nurses working in the selected sample of 164 practices received an invitation letter by mail or email, depending on the contact
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information provided in the NHSD. A reminder was sent four weeks after the initial invitation to all participating practices, as, due to the anonymous nature of the online questionnaire, it was not possible to identify who had participated. Depending on the medium that was used, the invitation either included an embedded link to the online questionnaire, or it directed the reader to a
webpage that provided the same embedded link. All potential participants were additionally encouraged to forward the study information to eligible colleagues, thus creating a snowball effect (Babbie 2010).
4.2.2 General Practitioners
All qualified GPs who were actively practicing in the non-metropolitan areas of Victoria, as defined in Section 3.2, were eligible to be included in the cross-sectional study. According to data from the Rural Workforce Agency Victoria (RWAV) (2016) there were 1,861 GPs located in areas outside major cities. A probability sampling technique was used with the help of the Medical Directory of Australia (MDA), which is the leading online medical database for searching and locating doctors and health facilities nationwide, endorsed by the Australian Medical Association (AMA) (2017). The use of the directory allowed for contacting potential participants directly and is, therefore, less reliant on practice gatekeepers, like practice managers and practice assistants. The MDA subscription, however, did not permit for the compilation and use of a mailing list. Therefore, the contact details of all GPs that, according to the MDA, worked at that time in the PHC system of non-metropolitan Victoria, were looked up, one by one, on screen. Their names were then manually entered in a temporary file, producing a sampling frame of 1568 GPs. It was suspected that this number differed from the 1,861 GPs documented by the RWAV because of potential variations in the classification of geographic boundaries of regional/rural regions, and because not all GPs are registered with the MDA.
Using STATA (StataCorp 2015), a sample of 309 GPs, identified by their MDA identification number and corresponding name, was randomly selected from the sampling frame. The sample size required was calculated based on a 95
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percent confidence interval and a five percent margin of error (Creative Research Systems 2012; O'Leary 2004). Of the selected sample, 22 GPs were either not found or they did not work in general practice, and two GPs were removed because their practice towns were not classified as a non-metropolitan area. To replete the loss of these 24 GPs, an additional random sample of 41 GPs was taken to provide for doubles and other exclusions. After screening, five names of this sample were indeed duplicates and, therefore, removed. A systematic sampling approach was then used, as this was the easiest and
quickest way to obtain the desired sample size (Creswell 2009). Every fifth GP on the list was chosen until the 24 additional GPs were acquired to complete the sample. Contact details of the 309 GPs were then obtained from the National Health Service directory (2017), a database of Australian health and related services, and the White Pages, and used to compile a mailing list.
Additionally, as the initial response of the GPs to the online questionnaire was low, a non-probability, purposive snowball sampling method was employed to recruit more non-metropolitan GPs with the required specifications. A contact person of Deakin University’s regional/rural clinical schools was asked to
introduce the study to GPs associated with these schools by sending them (non- personalised) invitation letters.
While it is widely acknowledged that primary care research is important for recommending clinical practice and to develop necessary evidence, GP recruitment for studies, and particularly for surveys, has proven to be
challenging (Pit, Vo & Pyakurel 2014; Zwar et al. 2006). As the validity of survey results dependents on a sufficient number of responses, a variety of strategies have been developed to increase response rates, most of them consistent with the principles of Dillman’s Total Design Approach (Dillman, Smyth & Christian 2014). This approach emphases five elements in survey design and
administration: inclusion of monetary incentives; a respondent-friendly survey layout; a multitude of reminders; enclosure of a stamped return envelope; and personalisation of the questionnaire. Four of Dillman’s strategies were employed in this study, as the enclosure of a stamped envelope was not required because
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an online questionnaire was used for data collection. All GP participants completing the questionnaire by the stated deadline were offered the opportunity to enter a random prize draw for a $500 AUD weekend away
voucher (Dillman, Smyth & Christian 2014; McLaren & Shelley 2000). Further, the mailed invitation letter sent to the 309 eligible GPs was personally addressed. All invitation letters, including the ones sent to GPs recruited via purposive snowball sampling, described the aim and purpose of the overall study and included a link to the questionnaire. The questionnaire was administered via the online survey tool Qualtrics (2015), which creates respondent-friendly and easy-to-use questionnaire layouts. Upon opening the questionnaire link, potential
participants were first guided to the PLSC form (Appendix A), after which they were required to click the text that outlined that they had read the statement, understood their rights as a participant, and that they wished to continue. Two reminders were sent with two months’ interval each.