Morelli 2010.

Study characteristics
Patient sampling	Primary objective: to determine whether relaxin and or its LGR7 receptor are expressed In human endometriotic tissues and whether their expression differs from that in endometrium of normal controls Participants: women undergoing surgery for findings of an ovarian cyst on USS Selection criteria: exclusion criteria: laparoscopic evidence and histologic confirmation of extra ovarian endometriosis at index surgery Study design: observational single‐gate, prospective sample collection
Patient characteristics and setting	Clinical presentation: ovarian cyst, not specified Age: range 24‐37 years Number enrolled: 40 women Number available for analysis: 40 women (11 in proliferative and 29 in secretory phase of the cycle) Setting: Department of Paediatrics, Obstetrics and Reproductive Medicine, University of Siena Place of study: Siena, Italy Period of study: October 2006 to May 2007 Language: English
Index tests	Index test: Relaxin mRNA, LGR7 receptor mRNA Description of positive case definition by index test as reported: LGR7 ‐ mRNA expression detected by RT‐PCR; Relaxin ‐ proportion of tissues expressing relaxin (detection by using the Rotor‐Gene 3000 PCR system (Corbett Research, CA) with using Platinum SYBR Green qPCR SuperMix (Invitrogen); normalised to β‐actin mRNA expression via 2‐ΔΔCt method; experiments described; thresholds not pre‐specified Examiners: none stated; unclear if blinded to the results of reference standard Interobserver variability: not provided
Target condition and reference standard(s)	Target condition: ovarian endometriosis Prevalence of target condition in the sample: n/N = 21/40 (52%): all stage III‐IV; controls 19 Reference standard: laparoscopy + histology Description of positive case definition by reference test as reported: laparoscopic evidence and histologic confirmation of extra ovarian endometriosis; staging according to the rASRM classification Examiners: none stated
Flow and timing	Time interval between index test and reference standard: samples were collected at surgery (appears from the context) Withdrawals: 8 patients with endometriosis were excluded as no tissue was available
Comparative
Notes	Conclusion: Significantly decreased expression of relaxin mRNA and LGR7 relaxin receptor mRNA in ectopic endometriotic tissues relative to their expression in eutopic endometrium and in endometrium from normal controls suggests that relaxin exerts a protective effect against endometriosis. Comment: For LGR7 relaxin receptor and relaxin mRNA there was no statistically significant difference between the groups; no data available for meta‐analysis (Appendix 7)
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	High
DOMAIN 2: Index Test All tests
Were the index test results interpreted without knowledge of the results of the reference standard?	No
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?	Unclear
Did all patients receive the same reference standard?	Yes
Were all patients included in the analysis?	No
		High