GPs: Sampling method and sample size

Stratified purposive sampling and snowball sampling were used to recruit frontline GPs from public and private settings. The study stratified the 283 GPs into two groups according to the nature of the practice (public or private) before the invitations were sent to all of them. In Hong Kong, public GPs are employed and serve in group-based public clinics or hospitals (Hong Kong Hospital Authority, 2017b). Alternatively, only 15% of private GPs serve in group-based clinical practices (Hong Kong Medical Association and Harvard University, 1998). In 2010, a study on primary care consultations found that patients reported significantly better experience in the private sector than in the public sector in Hong Kong (Wong et al., 2010). To foster a better understanding of organisational culture at the different levels of the organisation, GPs with various years of experiences were also recruited.

According to some accounts, the optimal sample size for thematic analysis is determined by thematic saturation of the data, meaning that data collection should go on until no new themes or patterns emerge from the data (Mason, 2010; O’Reilly &

Parker, 2012). Therefore, a total of 14 interviews were conducted, with seven GPs from public and private sectors respectively (Mason, 2010). Thematic saturation was achieved in both groups.

92 3.2.5 Selection of senior managers

3.2.5.1 Senior Managers: Inclusion and exclusion criteria Eligible senior managers:

1. Were currently working as a chief of service in family medicine in the Hospital Authority (Table 9) or

Were currently working as a chief medical director in one of the main private community medical groups in Hong Kong (Table 9) or

Were currently working as a chief executive under the Hong Kong Medical Council or Hong Kong College of Family Medicine in Hong Kong

2. Had a minimum of 1 year of full-time experience in managing a healthcare organisation.

Participants who did not fulfil the above criteria 1and 2 were excluded.

Table 9 Potential senior managers from the following institutions identified from relevant websites

93 3.2.5.2 Senior managers: Sampling method and sample size

Purposive and snowball sampling methods were used to select senior managers based on their position in affiliated organisations. In terms of how “senior manager” was defined, this included the chiefs of service in family medicine of a hospital, medical directors of private medical groups, senior administrators, managers and GP leaders who were knowledgeable not only about the organisational cultures of primary care practice within the department but also about the relationship between departments within their organisation. For this specific research topic, five managers from public, private and professional institutions were interviewed about their views on the organisational culture (specific to medication decision-making) and GPs’ perceived readiness to practise SDM within their organisation. However, thematic saturation was not possible among these senior managers, who had tight and busy schedules in managing their healthcare corporations.

94 3.2.6 Recruitment

Figure 5 Recruitment process

A total of 283 GPs and 64 senior managers who met the inclusion criteria to enter the recruitment stage were approached through an invitation via postal mail (Figure 5). An

95 invitation package (information sheet, expression of interest form, consent form, and a postage-paid return envelope) was sent to all potential participants (Appendices 10 to 19). A returned expression of interest form (by telephone/fax/email/post) indicated participants’ interest in joining the study (Appendices 12 and 17). Upon receiving the expression of interest form, the researcher telephoned the volunteering participants and screened them using the inclusion and exclusion criteria. Basic information was obtained, such as the nature of their practice, their clinical role, institution and years of clinical experience. Those who did not meet the eligibility criteria were informed immediately that they were not suitable for the study. Eligible participants were contacted again by the researcherwithin two weeks and a date, time and venue for the interview were agreed with the participant. At the end of the interview, each participant was invited to refer 2-3 potential participants by delivering a copy of the invitation package to these contacts.

I faced some challenges in the recruitment phase with a low response rate, which will be discussed in the strength and limitations section in Chapter 5. The senior managers explained that, being head of clinical teams, their schedules were packed with clinical and management meetings; a 10-minute interview was considered a luxury for them.

The researcher tried to seek help from the Hong Kong Medical Association and the Hong Kong Academy of Medicine to recruit more doctors, but they declined to help.

My local employer, the former Cluster and Hospital Chief Executive in the Hospital Authority, strongly advised against further recruitment using more radical approaches such as telephoning or emailing GPs directly as this could create a nuisance to the doctors. In the end, two boosting rounds of postal invitations were sent 2 months and 9 months after Phase 1.

96 3.2.7 Data collection

Fourteen GPs and five senior managers were interviewed at the JCSPHPC (n = 7), or at the working institution of the participant (n =10), or in a nearby private meeting or conference room (n =2) between November 2016 to December 2017. The researcher conducted semi-structured interviews with the use of a discussion guide to facilitate flow, depth and direction of the interview discussion (Appendices 13 and 18). The guide was used to draw the participant back to fulfil the study objectives in the event that discussions drifted off topic (Leung & Savithiri, 2009; Morimoto et al., 2015). The majority of the participants were bilingual, with their first language being Chinese. They were allowed to choose whether to conduct the interview in Chinese or English.

For pilot testing, the researcher invited two colleagues who were academic GPs to pre-test the Chinese and English topic guides. They suggested some minor amendments to wording and offered a concrete medication example of “Metformin” in the supplementary information sheet (Appendix 20). The researcher did not include these academic GPs in this study as they were full-time academics at the university who saw patients only occasionally at the outpatient clinics for research purposes.