Table 1.

Showing primary research features in articles included in analysis

	Aim Underpinning theory	Setting Participants	Sampling	Data collection	Analysis	Measures to support trustworthyness
Ballard et al.23 United Kingdom	Aim of study To investigate the reasons women experience delays in diagnosis of endometriosis and the impact of this Underpinning theory Not described	Setting Hospital pelvic pain clinic Participants 32 women Age: 16-47 years; (median 32) Years with pelvic pain: median 15 years	Sampling Not described Inclusion criteria confirmed or suspected endometriosis	Data collection Semi structured, face-to-face interviews, most often conducted in the home of the interviewee; 60-120 minutes Interviewer The author, social scientist	Analysis Thematic analysis where experiences and beliefs that women expressed were interpreted for key themes. Only women with confirmed endometriosis were included in the analysis Analysts Initial analysis by the author (a social scientist), refined after discussions with a pelvic pain specialist (gyneacologist) and a social scientist	Development of the coding frame and the initial analysis was carried out by a social scientist. The findings were then discussed with a consultant gynecologist and specialist in pelvic pain, and a social scientist. Based on these discussions, the analysis was further refined
Denny & Mann24 United Kingdom	Aims of study Explore experiences from primary care. Reanalysis of data from Denny 2004 Underpinning theory ?	Setting A clinic for endometriosis at a specialist women's hospital Participants 30 women Age: 19 - 44 years, (mean 31) Diagnostic delay: mean 5,65 years (0-18 years)	Sampling Purposeful. Inclusion criteria Laparoscopically verified endometriosis	Data collection Semi structured interview based on a story-telling approach, in their home or at the clinic; 30-50 minutes Probing for primary care if not mentioned spontaneously Interviewer The author, a social scientist	Analysis Thematic analysis (Bryman) Analysts The two authors, one social scientist and one gynecologist	Respondent validation of the themes Although there was no methodological triangulation, rigour was achieved in analysis as both authors and the women who participated in the study agreed the analytical themes as relevant and arising from the data.
Denny25 United Kingdom	Aim of study Explore women's experience of living with endometriosis. One-year follow- up Underpinning theory Feminist approach	Setting A clinic for endometriosis at a specialist women's hospital Participants Interviews: 27 women; Age: 19 - 44 years, (mean 31) Diary: 19 of these women	Sampling Purposeful (interviews) Not reported (diaries)	Data collection Semi structured interview based on a story-telling approach, in their home or at the clinic; 30-50 minutes Diary on endometriosis for one menstrual cycle; completed by 7 women Interviewer The author, a social scientist	Analysis Narrative analysis Analysts Only one author, social scientist	Respondent validation of the themes the women who participated in the study agreed the analytical themes as relevant and arising from the data.
Facchin et al.27 Italy	Aim of study Provide a broader understanding on how endometriosis affects psychological health Underpinning theory Grounded theory	Setting Tertiary level referral center for treatment of endometriosis Participants 74 women Age: 24 -50 years	Sampling Theoretical sampling Consecutively recruited Inclusion criteria Self-referred for treatment, surgically verified diagnosis, different forms of endometriosis	Data collection Face- to face interviews with a story-telling approach, conducted at the hospital Time: average 45 minutes Interviewer Trained psychologists including the first author	Analysis Constant comparative (Corbin & Strauss) Analysts Three, working independently	All emergent themes were continuously discussed in the research team Findings were presented to expert gynecologists and female members of a non-for-profit endometriosis association Discrepancies were discussed until consensus was reached
Gilmour et al.28 New Zealand	Aim of study Explore the perceptions of living with endometriosis Underpinning theory Feminist research principles	Setting Local endometriosis support group Participants 18 women Age: 16 to 45 years Diagnostic delay: 5-10 years	Sampling Interested women from the support group contacted the researchers after information about the project	Data collection Unstructured, interactive interview Interviewer Not described, but familiar with endometriosis and knowledgeable how to handle emotional reactions during the interview	Analysis Thematic analysis Analysts The authors, with a nursing background and working as researchers at a department for health and social services	Continuous collaboration with the support group Emerging themes were presented at two meetings and verified by the participants
Grundström et al.31 Sweden	Aim of study Identify and describe the experiences of health care encounters for women with endometriosis Underpinning theory phenomenology	Setting A university and a central hospital clinic Participants 9 women consecutively invited by three gynecologists in charge of their endometriosis treatment Age: 23-55 years (median 37 )	Sampling Purposive sampling Inclusion criteria Age >18 years Laparoscopy-verified endometriosis	Data collection Semi-structured interviews in the home or a separate room at the hospital library Length: 33-113 min (median 64 min) Interviewer Midwife and Doctoral student	Analysis Moustaka's modification of the Stevick-Colaizzi-Keen method (adding interpretation) Analysts Three researchers (two with midwife background, one a PhD student and the other a researcher, the third with a nursing background and researcher) conducted the analysis independently followed by discussion and consensus about the essence.	The methods used to establish trustworthiness in this study were reporting the audit trail (i.e., describing every step of the data collection and analysis), and using quotations to illustrate the themes and to show that the findings were grounded in the women's stories. To avoid overinterpretation, the research team analysed the data separately, discussed the analysis and found agreement in the interpretation.
Hållstam et al.32 Sweden	Aim of study To examine women's experience of painful endometriosis including long-term aspects, social consequences, impact of treatment and development of own coping strategies Underpinning theory Grounded theory	Setting At the specialized pain clinic of a tertiary center Participants 13 women Age: 24–48 years (mean 36)	Sampling Purposive sampling Inclusion criteria follow-up study after treatment for chronic pain at the clinic twenty-nine women were identified as having endometriosis	Data collection Semi-structured interviews most in a secluded place at the hospital, three in patients' homes, one at a workplace and one in a public library Length; 43- 82 min (mean 59 min). Interviewer Female nurse Female physiotherapist	Analysis Grounded theory (Corbin & Strauss) Analysts Two researchers (one nurse and one physiotherapist with experience of pain treatment and endometriosis and rehabilitation)	To ensure credibility research triangulation was performed. A peer review was done involving a gynecologist, a midwife, an anesthesiologist, a pain specialist and a physiotherapist all with experience of patients with endometriosis
Huntington & Gilmour29 New Zealand	Aim of study To explore women's perceptions of living with endometriosis, its effects on their lives and the strategies used to manage their disease. Underpinning theory Feminist research principles	Setting Local endometriosis support group Participants 18 women Age: 16 to 45 years Diagnostic delay: 5-10 years	Sampling Information sheets about the project and consent forms were distributed via newsletter Inclusion criteria	Data collection Individual, semi-structured, audio taped, interactive interviews Interviewer Not described, but familiar with endometriosis and knowledgeable how to handle emotional reactions during the interview	Analysis Thematic analysis Analysts The authors, with a nursing background and working as researchers at a department for health and social services	All texts were read, compared and tentative themes identified. Validity or ‘trustworthiness’ of the data in qualitative research relates to how well the data represents the experiences of the participants To determine the validity of the data from this research the findings were presented orally at two meetings of the endometriosis support group
Markovic et al.19 Australia	Aim of study to enrich our understanding of the relationship between the patient's socio-demographic background and health-related phenomena, by identifying distinctive differences among women's narratives. Underpinning theory Grounded theory—but influenced by endurance	Setting Women residing in the state of Victoria (Australia), with various gynecological conditions Participants 30 women Age 20 to 78 years (mean 43.9)	Sampling Information about the study was disseminated through community newspapers and notice boards; snowball sampling also occurred. Inclusion criteria Women self-selected	Data collection In-depth interviews, lasting for about 60 minutes Interviewer	Analysis Grounded theory (Corbin & Strauss) Analysts	This was an iterative process in which all authors read the transcripts and developed the coding book. They first identified the themes within individual transcripts and then checked them across narratives. The themes were identified inductively, by careful reading of the interview data, but also by searching for themes identified in prior research in the area of women's reproductive health, as presented in the introduction. Themes were included in the grounded theory only if a significant number of women (about half) spoke about them
Moradi et al.20 Australia	Aim of study to explore women's experiences of endometriosis and its impact, involving three different age groups recruited either from both a hospital clinic and the community. Underpinning theory	Setting 23 women from a dedicated Endometriosis Centre at one public teaching hospital in Canberra and 12 women from the community (who had not attended the Centre) Participants 35 women Age 17 to 53 years (mean 31.1)	Method women was purposefully recruited Inclusion criteria confirmed diagnosis of endometriosis (via laparoscopy) for at least a year, who were able to understand and speak English, and had no other chronic disease.	Data collection Focus groups interviews lasting for about 2.5 h Interviewer Two experienced health professionals with practical knowledge about endometriosis and interviewing skills.	Analysis Thematic analysis (Braun & Clarke) Analysts The whole research team was involved?	Rigour refers to the quality of qualitative enquiry and is used as a way of evaluating qualitative research. Seven participants from different focus groups were asked to check a transcription of their responses and confirmed its accuracy.
Jones et al.26 United Kingdom	Aim of study Explore and describe the impact of endometriosis on quality of life Underpinning theory Grounded theory to generate categories and concepts	Setting Gynecology outpatient clinic Participants 24 women (until theoretical saturation) Age:21,5-44 years (mean 32,5)	Method Theoretical sampling to cover different disease stages and symptom profiles Inclusion criteria Laparoscopically verified endometriosis	Data collection Semi-structured, in depth interviews at the hospital Mean time: 55 min Interviewer the researcher had no personal experience of endometriosis and only very basic knowledge of its symptoms before the interviews started	Analysis Constant comparative method Analysts Not described	Independent coding for some transcripts by a research nurse To reduce interviewer bias and to check whether the codes adequately reflected the emerging areas of HRQoL, a research nurse also went through some of the transcripts. The same themes were identified and the interviewees' dialogues were interpreted in the same way.
Roomaney & Kagee30 South Africa	Aim of study To explore, understand and describe HRQOL among South African women diagnosed with endometriosis. Underpinning theory Quality of life	Setting In both the private and public health systems at the Western Cape Province of South Africa (gynaecological departments/practices) Participants 25 women laparoscopically diagnosed with endometriosis Age: 25- 42 years (average age 33)	Method Convenience sampling Inclusion be surgically diagnosed with endometriosis, be 18 years or older and have experienced symptoms during the 3 months prior to being interviewed	Data collection Semi-structured interviews at participants' homes, places of work, the researcher's office or coffee shops Length: 31- 84 minutes Interviewer Not described	Analysis Thematic analysis (Braun and Clarke) Analysts The two authors	Both authors checked and re-checked the codes to ensure consistency in the data analysis. In addition, an independent coder was employed to verify the data analysis. Five interviews were coded independently and then compared. Any differences between codes were discussed until a consensus was reached regarding the labelling of codes. A code-book was developed during this process, and the first author used the code-book to code. the remaining interviews. We reviewed samples of coding of the data in order to enhance trustworthiness of analysis.
Seear21 Australia	Aim of study Examine the potentially broader application of these findings for the study of menstrual pain and chronic pelvic pain conditions more generally Underpinning theory a ‘discrediting attribute’ (Goffman, 1963) the ‘menstrual etiquette’ (Laws, 1990)	Setting From a qualitative study conducted in Australia Participants 20 women Age:24 - 55 years (mean 34).	Method snowball sampling and advertisement was also placed in the newsletter of an Australian support group	Methods semi-structured interviews Length of interviews: 45min to 2 h Interviewer Not described	Analysis Secundary analysis- (Miles and Huberman) Analysts Not described	A system of diagrams or ‘charts’ were used to display the data and the relationships between emergent themes. Following this process, the researcher returned to the original transcripts of interviews several times to check that the themes and concepts that I had been developed were supported by the data. Any negative cases were noted.
Young et al.22 Australia	Aim of study Explore experiences of health care related to endometriosis and fertility Underpinning theory Not described	Setting Non-clinical Participants 26 women, the majority in their 30s	Method invitation by advertisements. After 20 interviews purposeful sampling was applied to ensure diversity Inclusion criteria At least 18 years Surgically verified endometriosis	Methods In depth, semi-structured interviews, face-to face or over the phone Mean time: 63 minutes Interviewer First author	Analysis Thematic analysis (Braun & Clarke) Analysts Initial analysis by the first author and then all authors participated in the analysis and interpretation of data,	Analysis, the hierarchy of themes, and final categories of data were discussed among all authors and results were decided by agreement.

HRQoL, health-related quality of life.