Diagnostic accuracy of tests for type 2 diabetes and prediabetes: A systematic review and meta-analysis

• Published in: PloS one 2020-11, Vol.15 (11), p.e0242415
• Main Authors: Kaur, Gunjeet, Lakshmi, P V M, Rastogi, Ashu, Bhansali, Anil, Jain, Sanjay, Teerawattananon, Yot, Bano, Henna, Prinja, Shankar
• Format: Article
• Language: English
• Subjects: Accuracy; Adult; Adults; Biology and life sciences; Bivariate analysis; Blood Glucose - analysis; Costs; Diabetes; Diabetes mellitus; Diabetes mellitus (non-insulin dependent); Diabetes Mellitus, Type 2 - blood; Diabetes Mellitus, Type 2 - diagnosis; Diagnosis; Diagnostic systems; Diagnostic Techniques and Procedures; Disease; Endocrinology; Evaluation; Fasting; Female; Glucose; Glucose tolerance; Glucose Tolerance Test - methods; Glycated Hemoglobin - analysis; Health screening; Hemoglobin; Humans; Hyperglycemia - diagnosis; Hyperglycemia - pathology; Laboratory testing; Likelihood ratio; Male; Mass Screening - methods; Medical diagnosis; Medical education; Medicine; Medicine and Health Sciences; Meta-analysis; Methods; Mortality; Physical Sciences; Prediabetic state; Prediabetic State - blood; Prediabetic State - diagnosis; Public health; Quality assessment; Quality control; Research and Analysis Methods; Reviews; Screening; Sensitivity and Specificity; Sustainable development; Systematic review; Type 2 diabetes; Websites
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0242415

This systematic review aimed to ascertain the diagnostic accuracy (sensitivity and specificity) of screening tests for early detection of type 2 diabetes and prediabetes in previously undiagnosed adults. This systematic review included published studies that included one or more index tests (random and fasting tests, HbA1c) for glucose detection, with 75-gram Oral Glucose Tolerance Test (or 2-hour post load glucose) as a reference standard (PROSPERO ID CRD42018102477). Seven databases were searched electronically (from their inception up to March 9, 2020) accompanied with bibliographic and website searches. Records were manually screened and full text were selected based on inclusion and exclusion criteria. Subsequently, data extraction was done using standardized form and quality assessment of studies using QUADAS-2 tool. Meta-analysis was done using bivariate model using Stata 14.0. Optimal cut offs in terms of sensitivity and specificity for the tests were analysed using R software. Of 7,151 records assessed by title and abstract, a total of 37 peer reviewed articles were included in this systematic review. The pooled sensitivity, specificity, positive (LR+) and negative likelihood ratio (LR-) for diagnosing diabetes with HbA1c (6.5%; venous sample; n = 17 studies) were 50% (95% CI: 42-59%), 97.3% (95% CI: 95.3-98.4), 18.32 (95% CI: 11.06-30.53) and 0.51 (95% CI: 0.43-0.60), respectively. However, the optimal cut-off for diagnosing diabetes in previously undiagnosed adults with HbA1c was estimated as 6.03% with pooled sensitivity of 73.9% (95% CI: 68-79.1%) and specificity of 87.2% (95% CI: 82-91%). The optimal cut-off for Fasting Plasma Glucose (FPG) was estimated as 104 milligram/dL (mg/dL) with a sensitivity of 82.3% (95% CI: 74.6-88.1%) and specificity of 89.4% (95% CI: 85.2-92.5%). Our findings suggest that at present recommended threshold of 6.5%, HbA1c is more specific and less sensitive in diagnosing the newly detected diabetes in undiagnosed population from community settings. Lowering of thresholds for HbA1c and FPG to 6.03% and 104 mg/dL for early detection in previously undiagnosed persons for screening purposes may be considered.