Evaluating the diagnostic accuracy of androgen measurement in polycystic ovary syndrome: a systematic review and diagnostic meta-analysis to inform evidence-based guidelines

BACKGROUND: Biochemical hyperandrogenism is a hallmark and diagnostic feature of polycystic ovary syndrome (PCOS). However, the most accurate androgen measurement for assessing biochemical hyperandrogenism in PCOS diagnosis remains uncertain. OBJECTIVE AND RATIONALE: This systematic review aimed to assess different androgen measures [including total testosterone (TT), calculated free testosterone (cFT), free androgen index (FAI), androstenedione (A4), dehydroepiandrosterone sulfate (DHEAS), and dihydrotestosterone (DHT)] for accuracy in diagnosing biochemical hyperandrogenism in women with PCOS, to inform the 2023 International PCOS Evidence-based Guidelines. SEARCH METHODS: To update evidence from the 2018 International PCOS Guidelines, a systematic search from 3 July 2017 to 23 June 2023 was conducted across Medline (Ovid), CINAHL, all EBM, EMBASE, and PsycInfo for articles evaluating androgens in the diagnosis of biochemical hyperandrogenism. The revised Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) was used to assess the risk of bias and applicability. A diagnostic test accuracy meta-analysis was performed using STATA 18 software. Summary sensitivity and specificity were calculated with 95% CIs using the bivariate model, while the hierarchical summary receiver operating characteristics (ROC) model was used to produce a summary ROC curve. OUTCOMES: Of 23 studies reviewed, 18 were included in the meta-analysis, with data from 2857 participants (1650 with PCOS and 1207 controls). For diagnosing biochemical hyperandrogenism in PCOS, the pooled sensitivity, specificity, and AUC with 95% CI were for TT: 0.74 (0.63-0.82), 0.86 (0.77-0.91), and 0.87 (0.84-0.90); cFT: 0.89 (0.69-0.96), 0.83 (0.79-0.86), and 0.85 (0.81-0.88); FAI: 0.78 (0.70-0.83), 0.85 (0.76-0.90), and 0.87 (0.84-0.90); A4: 0.75 (0.60-0.86), 0.71 (0.51-0.85), and 0.80 (0.76-0.83); and DHEAS: 0.75 (0.61-0.85), 0.67 (0.48-0.81), and 0.77 (0.73-0.81), respectively. In subgroup analyses, liquid chromatography with tandem mass spectrometry (LC-MS/MS) had superior sensitivity for measuring cFT, FAI, A4, and DHEAS, and superior specificity for measuring TT, cFT, and FAI, compared to the direct immunoassay method. WIDER IMPLICATIONS: Our results directly informed the 2023 International PCOS Guideline recommendations to use TT and FT as the first-line laboratory tests to assess biochemical hyperandrogenism in the diagnosis of PCOS. cFT should be assessed by equilibrium dialysis or ammonium sulfate precipitation, or calculated using FAI. If TT or cFT are not elevated, A4 and DHEAS could also be considered, noting their poorer specificity. Laboratories should utilize LC-MS/MS for androgen measurement given its high accuracy. Future studies should focus on establishing optimal normative cut-off values in large, unselected, and ethnically diverse cohorts of women. REGISTRATION NUMBER: The review protocol was prepublished in the 2023 PCOS Guideline Technical Report (https://www.monash.edu/__data/assets/pdf_file/0010/3379591/TechnicalReport-2023.pdf).