Diagnostic utility of speech-based biomarkers in mild cognitive impairment: a systematic review and meta-analysis

Among various tools developed for mild cognitive impairment (MCI) detection, analysing speech features is a non-invasive and cost-effective approach that shows promise for early detection. This review aimed to systematically synthesise and analyse current evidence on the diagnostic utility of speech-based biomarkers for identifying MCI.

A systematic review and meta-analysis were conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. PubMed, Scopus, Ovid Medline and PsycINFO databases were searched up to April 2025 without restrictions on language, article status or year.

Of 4432 identified records, 54 peer-reviewed articles met the inclusion criteria. Fixed-effects meta-analyses showed pooled estimates of 80.0% 'accuracy' [95% confidence intervals (CI): 70.0%-89.0%, P < .001, n = 21], 78.0% 'area under the curve' (95% CI: 70.0%-86.0%, P < .001, n = 21), 80.0% 'sensitivity' (95% CI: 71.0%-90.0%, P < .001, n = 22), and 77.0% 'specificity' (95% CI: 65.0%-89.0%, P < .001, n = 15) in differentiating MCI from cognitively unimpaired (CU) individuals. Egger's regression tests indicated no publication bias (P ≥ .299), and the I2 statistic revealed no heterogeneity across studies (I2 = 0.00%, P = 1.00). Four studies also included a subjective cognitive decline group, reporting significant differences in certain speech features compared to CU.

Speech analysis demonstrates moderate classification performance, with balanced sensitivity and specificity, in distinguishing MCI from CU, suggesting its potential as an accurate and cost-effective diagnostic tool for MCI detection. Further research is needed to address variations in study methodologies, refine speech analysis protocols and validate findings in diverse populations to enhance generalisability.