Reproducibility of the Endometriosis Fertility Index: a prospective inter-/intra-rater agreement study.

OBJECTIVE

To evaluate the reproducibility of the Endometriosis Fertility Index (EFI).

DESIGN

Single-cohort prospective observational study.

SETTING

University hospital.

POPULATION

Women undergoing laparoscopic resection of any rASRM-stage endometriosis.

METHODS

Details of pre- and peroperative findings were collected into a coded research file. EFI scoring was performed en-bloc by three different raters (expert-1 [C.T.], expert-2 [C.M.], junior [C.B.]). Required sample size: 71. Definitions used for agreement: clinical (scores within same range: 0-4, 5-6, 7-10) and numerical (difference ≤1 EFI point).

MAIN OUTCOME MEASURES

Primary outcome: rate of clinical agreement between two experts.

SECONDARY OUTCOMES

expert numerical agreement, clinical and numerical agreement between expert-1 and junior, and within expert-1 (intra-observer), agreement of rASRM score and -stage.

RESULTS

A near 'inter-expert' clinical agreement rate (1.000, 95% CI 0.956-1.000; P = 0.0149) was observed. The numerical agreement between two experts was also high (0.988, 95% CI 0.934-1.000); similarly, high agreement rates were observed for both 'junior-expert' comparisons (clinical 0 .963, 95% CI 0.897-0.992; numerical 0.988, 95% CI 0.934-1.000) and 'intra-expert' comparisons (clinical 0.988, 95% CI 0.934-1.000; numerical 1.000, 95% CI 0.956-1.000). Reasons for disagreements were different scoring of the least-function score and disagreements in rASRM scores. The reproducibility of the rASRM score was clearly inferior to that of the EFI for all comparisons.

CONCLUSION

The EFI can be reproduced reliably by different raters, further supporting its use in daily clinical practice as the principal clinical tool for postoperative fertility counselling/management of women with endometriosis.

TWEETABLE ABSTRACT

A study confirming the high reproducibility of the EFI substantiates its use in daily clinical practice.