Tawanda Chivese1, Jennifer Hirst2, Joshua T Matizanadzo3, Michael Custodio4, Andrew Farmer2, Shane Norris5, Naomi Levitt6. 1. Department of Population Medicine, College of Medicine, QU Health, Qatar University, Doha, Qatar. 2. Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK. 3. Department of Public Health and Primary Care, Brighton & Sussex Medical School, Brighton, UK. 4. Division of Epidemiology and Biostatistics, Department of Global Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa. 5. SAMRC/Wits Developmental Pathways for Health Research Unit, Department of Paediatrics, Faculty of Medicine and Health Sciences, University of the Witwatersrand, Johannesburg, South Africa. 6. Chronic Disease Initiative for Africa, Department of Medicine, Faculty of Medicine and Health Sciences, University of Cape Town, Cape Town, South Africa.
Abstract
OBJECTIVE: To assess the diagnostic accuracy of glycated haemoglobin A1c (HbA1c ), compared to fasting plasma glucose (FPG) and the oral glucose tolerance test (OGTT), in screening for type 2 diabetes (T2D) in Africa. METHODS: We systematically searched databases for studies that compared the HbA1c to either the OGTT, or the FPG for T2D diagnosis were included. The QUADAS 2 tool was used for assessing the quality of included studies. We used the split component synthesis (SCS) method for the meta-analysis of diagnostic accuracy studies to pool the studies for meta-analysis of sensitivity and specificity, primarily at the HbA1c ≥48 mmol/mol (6.5%) cut-off and at other cut-offs. We assessed heterogeneity using the I2 statistic and publication bias using Doi plots. RESULTS: Eleven studies, from seven African countries, with 12,925 participants, were included. Against the OGTT, HbA1c ≥48 mmol/mol (6.5%) had a pooled sensitivity of 57.7% (95% confidence interval [CI] 43.4-70.9) and specificity of 92.3% (95% CI 83.9-96.5). Against the FPG, HbA1c ≥48 mmol/mol (6.5%) had a pooled sensitivity of 64.5% (95% CI 50.5-76.4) and specificity of 94.3% (95% CI 87.9-97.5). The highest sensitivity for HbA1c , against the OGTT, was at the 42 mmol/mol (6.0%) cut-off. CONCLUSION: In Africa, the HbA1c ≥48 mmol/mol (6.5%) cut-off may miss almost half of the individuals with T2D based on blood glucose measures.
OBJECTIVE: To assess the diagnostic accuracy of glycated haemoglobin A1c (HbA1c ), compared to fasting plasma glucose (FPG) and the oral glucose tolerance test (OGTT), in screening for type 2 diabetes (T2D) in Africa. METHODS: We systematically searched databases for studies that compared the HbA1c to either the OGTT, or the FPG for T2D diagnosis were included. The QUADAS 2 tool was used for assessing the quality of included studies. We used the split component synthesis (SCS) method for the meta-analysis of diagnostic accuracy studies to pool the studies for meta-analysis of sensitivity and specificity, primarily at the HbA1c ≥48 mmol/mol (6.5%) cut-off and at other cut-offs. We assessed heterogeneity using the I2 statistic and publication bias using Doi plots. RESULTS: Eleven studies, from seven African countries, with 12,925 participants, were included. Against the OGTT, HbA1c ≥48 mmol/mol (6.5%) had a pooled sensitivity of 57.7% (95% confidence interval [CI] 43.4-70.9) and specificity of 92.3% (95% CI 83.9-96.5). Against the FPG, HbA1c ≥48 mmol/mol (6.5%) had a pooled sensitivity of 64.5% (95% CI 50.5-76.4) and specificity of 94.3% (95% CI 87.9-97.5). The highest sensitivity for HbA1c , against the OGTT, was at the 42 mmol/mol (6.0%) cut-off. CONCLUSION: In Africa, the HbA1c ≥48 mmol/mol (6.5%) cut-off may miss almost half of the individuals with T2D based on blood glucose measures.
Authors: Andre Pascal Kengne; Tandi E Matsha; David B Sacks; Annalise E Zemlin; Rajiv T Erasmus; Anne E Sumner Journal: EClinicalMedicine Date: 2022-05-23