The value of serum-free androgen index in the diagnosis of polycystic ovary syndrome: A systematic review and meta-analysis

J Obstet Gynaecol Res. 2021 Apr;47(4):1221-1231. doi: 10.1111/jog.14681. Epub 2021 Feb 8.


Objective: It is found that there is a significant difference in serum-free androgen index (FAI) between patients with polycystic ovary syndrome (PCOS) and healthy people, and the selection of appropriate cutoff value has a certain diagnostic value for PCOS. However, the current research conclusions on the diagnostic value of FAI for PCOS are not consistent. The purpose of this study is to explore the diagnostic value of FAI in PCOS, in order to provide reference for clinicians to select appropriate diagnostic indicators in the future.

Methods: Cochrane Library, Medline, Excerpta Medica Database, China National Knowledge Infrastructure, and China Wanfang database were searched until July 2020. A comprehensive collection of FAI studies on the diagnosis of PCOS was conducted. The pooled sensitivity, specificity, diagnostic odds ratio (DOR), positive likelihood ratio (+LR), and negative likelihood ratio (-LR) were analyzed by Stata15.0 software, and the receiver operating characteristic (ROC) curves of the subjects were drawn.

Results: A total of seven high-quality clinical studies were included. The results of meta-analysis showed that the pooled sensitivity = 0.76 (95% confidence interval [CI]: 0.69 ~ 0.82), specificity = 0.82 (95%CI: 0.69 ~ 0.90), +LR = 4.12 (95%CI: 2.12 ~ 4.03), -LR = 0.29 (95%CI: 0.22 ~ 0.38), DOR = 14.08 (95%CI: 7.13 ~ 27.83), and the area under ROC was 0.84.

Conclusion: FAI has a moderate diagnostic value for PCOS. It may be possible to add new experimental designs to find the best cut-off value for FAI diagnosis to improve the diagnostic efficacy.

Keywords: cut-off value; diagnosis; free androgen index; meta-analysis; polycystic ovary syndrome.

Publication types

  • Meta-Analysis
  • Review
  • Systematic Review

MeSH terms

  • Androgens* / analysis
  • China
  • Female
  • Humans
  • Odds Ratio
  • Polycystic Ovary Syndrome* / diagnosis
  • ROC Curve


  • Androgens