Szymanowski 2003.

Study characteristics
Patient sampling	Primary objective: to describe the expression of α3β1, α4β1 and β1 integrin chain in endometrial biopsy in women suffering from endometriosis Participants: women with infertility, pelvic pain or both undergoing laparoscopy and hysteroscopy Selection criteria: inclusion criteria: regular cycles, no hormonal treatment at least 1/12 month prior surgery; exclusion criteria: pregnancy, non‐peritoneal endometriosis Study design: observational single‐gate, prospective sample collection
Patient characteristics and setting	Clinical presentation: infertility ‐ 23/32, pelvic pain ‐ 11/32 Age: mean age 29.2 ± 4.19 years Number enrolled: 32 women Number available for analysis: 32 women (all in secretory phase) Setting: university hospital ‐ Division of Reproduction, K. Marcinkowski University of Medical Sciences Place of study: Poznan, Poland Period of study: January 1998 to June 2000 Language: English
Index tests	Index test: α3β1, α4β1 and β1 Integrin chain Description of positive case definition by index test as reported: Positive IHC staining (staining intensity was defined as weak +, moderate ++, strong +++; not defined in glandular and stromal cells); threshold not pre‐specified Examiners: blinded observer Interobserver variability: not provided
Target condition and reference standard(s)	Target condition: peritoneal endometriosis Prevalence of target condition in the sample: n/N = 17/32 (53%): stage not specified; controls 15 Reference standard: laparoscopy + histology Description of positive case definition by reference test as reported: direct visualisation of endometrial foci with histological confirmation; rAFS classification Examiners: not stated
Flow and timing	Time interval between reference test and index test: tissue sample was obtained at surgery Withdrawals: none reported
Comparative
Notes	Conclusion: The selected integrins do not yet allow identification of a pattern characteristic for endometriosis.
Methodological quality
Item	Authors' judgement	Risk of bias	Applicability concerns
DOMAIN 1: Patient Selection
Was a consecutive or random sample of patients enrolled?	No
Did the study avoid inappropriate exclusions?	Yes
Was a 'two‐gate' design avoided?	Yes
		High	Unclear
DOMAIN 2: Index Test All tests
Were the index test results interpreted without knowledge of the results of the reference standard?	Yes
If a threshold was used, was it pre‐specified?	No
Was a menstrual cycle phase considered in interpreting the index test	Yes
		High	Low
DOMAIN 3: Reference Standard
Is the reference standards likely to correctly classify the target condition?	Yes
Were the reference standard results interpreted without knowledge of the results of the index tests?	Yes
		Low	Low
DOMAIN 4: Flow and Timing
Was there an appropriate interval between index test and reference standard?	Yes
Did all patients receive the same reference standard?	Yes
Were all patients included in the analysis?	Yes
		Low