Sample size and data saturation

An appropriate sample size for a qualitative study is one that adequately answers the research question. How large should the sample size be? Is the sample large enough?

For example, Manson (2000) identified a mean sample size of 31 as a result of investigating a sample of PhD studies using qualitative approaches and qualitative interviews as the method of data collection. Meanwhile, Morse (1994, p. 225) outlined more detailed guidelines, recommending at least six participants for phenomenological studies, approximately 30-50 participants for ethnographies, grounded theory studies, and ethno-science studies; and 100-200 units of the item being studied in qualitative ethology. Creswell (1998), on the other hand, recommended between five and 25 interviews for a phenomenological study and 20-30 for a grounded theory study.

However, Holloway and Wheeler (2010) indicate that sample size in qualitative research does not necessarily determine the importance of the study or the quality of the data. A larger sample is unnecessary because an over-large sample might result in less depth and richness and miss out on the meanings of participants based on their experience. It could result in the loss of the unique and specific. In the same respect, Todres et al., (2005) stress that even a sample of one can be meaningful (p. 146).

O’Reilly and Parker (2012), cited in Fossey et al. (2002) in a qualitative inquiry, indicated that the aim is not to acquire a fixed number of participants; rather it is to acquire a sufficient depth of information in order to fully describe the phenomenon

concept of saturation or the point at which no new information or themes are observed in the data (Guest et al., 2006, p. 59). Marshall (1996) emphasised with regard to data saturation that the number of required subjects usually becomes obvious as the study progresses, and as new categories, themes or explanations stop emerging from the data in practice (p. 523).

Morse (1995) observed that “saturation is the key to excellent qualitative work”, but at the same time indicated that “there are no published guidelines or tests of adequacy for estimating the sample size required to reach saturation” (p. 147). According to Morse (1995), saturation is defined as ‘data adequacy’ and operationalised as collecting data until no new information is obtained, and the signals of saturation seem to be determined by investigator proclamation and by evaluating the adequacy and the comprehensiveness of the results (p. 148).

With this in mind, to understand this study of the phenomenon of medical tourism, the sample size shown in Table 17 has achieved confidence in regard to sufficient depth of information and data saturation.

Table 17 Sample size of research participants

Research participants Total

Medical tourism

In-depth Interview Report for the Development of South Korean Medical Tourism 2013 (n=1)

2013 Statistics on International Patients in Korea (n=1)

2013 International Patient Satisfaction Survey (n=1)

Korea Medical Tourism Overview 2013 (n=1)

N=4

The following presents the details of overall data collections with the questions to be answered from the research participants.

4.5.3.1 Industry reports

As has been mentioned, written documents can also be extremely valuable as they provide evidence for additional important issues which the research might otherwise have missed. In particular, the four latest industry reports were included not only to support the units of analysis, but also to provide the picture of South Korean medical tourism. Two of these reports relevant to this research were accessed and downloaded from the website of the KHIDI and two reports by the KTO, which were obtained during the interview with an executive director of the Medical Tourism Department at the KTO, were specifically used (Table 18).

Table 18 Details of industry reports from KTO and KHID

Documents Date Method Data reviews

2013

•   Identification of roles of medical tourism providers

•   Major medical procedures of South Korean medical

•   Overall satisfaction by country

•   Correlation coefficient between the satisfaction of overall medical services and each of the criteria by word cloud in Korean

4.5.3.2 In-depth interview questions with industry stakeholders After the interview questions were designed based on the research of Heung et al.

(2011), they were pre-tested with a small number of medical tourism experts in South Korea during a visit in November 2013. A small number of errors in the questions were discovered and corrected, and the wording was improved as structured (Figure 19).

Figure 19 Structure of in-depth interview questions for industry stakeholders

With confidence in the interview questions, around 100 email invitations were sent to the South Korean medical tourism practitioners including tourism academics, for the participants in March 2014. However, there were only a few replies, answering that they did not have sufficient knowledge for this in-depth study of medical tourism.

Faced with this difficulty in recruiting participants, Myers’s (2009) proposition was considered:

It is possible to conduct a case study that is that based almost entirely on a few interviews with key people. It is extremely important to identify and interview ‘key’ informants. Key informants are those who know the most about a particular topic in the organization and have decision-making

With this in mind, to recruit the key participants as well as to understand and investigate the current situation of South Korean medical tourism closely, the 6th Korean Medical Tourism Forum was attended, and a course of the 2nd International Medical Tourism Experts at the Korean Medical Tourism Association was taken in October 2014. The interviews were conducted during the stay, and meetings were undertaken with people who were actively engaged in this particular area. The interviewees were deliberately selected, and asked to participate face-to-face, by email and by telephone.

However, some refused or were delayed by their own busy schedules. Finally, the data collection process started in the government body in charge of medical tourism, and explored a medical tourism association, hospital and medical tourism facilitator as detailed below. The interviews were all recorded, taking between one and one and a half hours, and were confirmed by emailing the typed transcript of each interviewee.

With some interviewees having difficulty finding the time to participate, their responses were taken by email.

Thus, a total of seven key representatives of medical tourism industry stakeholders participated in the in-depth study (Table 19).

Table 19 Details of research participants from industry stakeholders

Research

Participants Interviewees Experiences

on the field

Interview Duration Government Executive Director

Medical Tourism Department KTO (Korea Tourism Organisation)

2 years (30 years at KTO)

1 hour

Association 1 President, M. D., PhD

KMTA (Korea Medical Tourism Association)

10 years 1 hour

Association 2 Team Leader

AKMT (The Alliance of Korea Medical Tourism)

Facilitator 1 Representative Director

K-Dream (Medical tourism agency)

6 years Email

Facilitator 2 Managing Director

Four Seasons Tour and Travel (Travel agency)

10 years Email

4.5.3.3 Semi-structured questions with prospective medical tourists

After holding in-depth interviews with industry stakeholders as key informants of this research, it was possible to understand aspects of their business from their statements of problems, hearing from the real people on the field.

With this in mind, to achieve the aim of this study, the semi-structured questions for prospective customers were designed during the analysis stage of industry stakeholders based on the interview questions and contents. Biographical data such as age, gender, education, employment, residence and ethnicity were also included to investigate any relevant issues.

Furthermore, the last question, 18, with a six-point Likert scale, was designed to find out how people have perceived the level of each criteria regarding medical tourism in terms of a numerical value. The idea of adding the Likert scale was to allow

presented in detail in the analysis in Chapter 6.

After creating this questionnaire, it was checked and updated in relation to the conceptual framework and research questions (Figure 20). During the data collection, some confusion arose in answering the key questions 10 and 11 regarding the benefits and sacrifices of medical tourism. Thus, words were added to clarify the positive and negative aspects for the research participants’ better understanding.

Figure 20 Structure of semi-structured questions for prospective medical tourists

To recruit participants with respect for their privacy and freedom, the semi-structured questions were distributed from January to August 2015, face-to-face and by email and social media such as Facebook and LinkedIn, asking if anyone would be interested to volunteer. By the end, a total of 45 people had been recruited (Table 20) and they were kept by numbers (Appendix 7).

Table 20 Details of research participants from prospective medical tourists

Biographical Data Prospective medical tourists

The following provides more details of the procedures of the data analysis.