Point‐of‐care testing of capillary glucose in the exclusion and diagnosis of diabetes in remote Australia

Abstract

Objectives: To determine the utility of point‐of‐care (POC) capillary blood glucose measurements in the diagnosis and exclusion of diabetes in usual practice in primary health care in remote areas. Design: Cross‐sectional study comparing POC capillary glucose results with corresponding venous glucose levels measured in a reference laboratory. Participants: 200 participants aged 16–65 years enrolled: 198 had POC capillary glucose measurements; 164 also had acceptable venous glucose laboratory results. Setting: Seven health care sites in the Kimberley region of Western Australia from May to November 2006. Main outcome measures: Concordance and mean differences between POC capillary blood glucose measurement and laboratory measurement of venous blood glucose level; POC capillary blood glucose equivalence values for excluding and diagnosing diabetes, and their sensitivity, specificity and positive‐predictive value. Results: The concordance between POC and laboratory results was high (ρ = 0.93, P < 0.001). The mean difference in results was 0.48 mmol/L (95% CI, 0.23–0.73; limits of agreement, − 2.6 to 3.6 mmol/L). The POC capillary glucose equivalence values for excluding and diagnosing diabetes were < 5.5 mmol/L (sensitivity, 53.3%; specificity, 94.4%; positive‐predictive value, 88.9%; for a venous value of < 5.5 mmol/L) and ≥ 12.2 mmol/L (sensitivity, 83.3%; specificity, 99.3%; positive‐predictive value, 95.2%; for a venous value of ≥ 11.1 mmol/L), respectively. While the choice of glucometer and whether or not patients were fasting altered these results, they did not have a significant influence on the diagnostic utility of POC glucose measurement in this setting. Conclusion: POC capillary blood glucose analysers can be used as part of the process of diagnosing and excluding diabetes in remote rural communities using these locally established capillary equivalence values.

Validation of Point-of-Care Glucose Testing for Diagnosis of Type 2 Diabetes

“…However, in a recent report, Ritchie et al emphasized the utility of modern POC-glucose testing for screening purposes in a high-risk rural population [10], confirming previous evidence from epidemiological studies in remote areas [9], and the general population [11]. This data, as well as our evidence that shows that state-of-the-art POC-glucose technology can be used reliably as a diagnostic tool as well, demonstrates that the evolving technology of POC-glucose testing can offer many advantages beyond glucose monitoring.…”

“…However, despite many obvious advantages (low sample volume, short turnaround time, and availability outside of the laboratory) and ongoing improvements in analytical performance, there is limited evidence on the possible use of POC glucose testing for diagnostic purposes, and results collected so far remained controversial [6–8]. Although some evidence from epidemiological studies suggest that POC glucose meters could be helpful in screening for diabetes, particularly in remote areas [9–11], their use in the diagnosis of diabetes is not recommended, due to both insufficient precision and accuracy and the inherent, sample-dependent flaw of results [1–3]. Namely, whole blood glucose, as measured by POC glucose meters, is approximately 11% lower than plasma glucose, but the difference is hematocrit dependent.…”

Comparison of Near-Patient Capillary Glucose Measurement and a Risk Assessment Questionnaire in Screening for Type 2 Diabetes in a High-Risk Population in Rural India

“…Several prior studies have analyzed the utility of POC capillary glucose as a diagnostic test with varied results (14–16). Two of these studies specifically examined the utility of POC testing among high-risk populations (15,16).…”

“…Two of these studies specifically examined the utility of POC testing among high-risk populations (15,16). One study in the Australian indigenous population (15) found that POC glucose had good discriminatory capacity for predicting undiagnosed diabetes (using fasting venous glucose as the standard), and the other study in Maori (16) found that POC glucose had acceptable discriminatory capacity (using OGTT as the gold standard). The differing levels of discrimination achieved may reflect diabetes presenting as fasting hyperglycemia compared with diabetes presenting as postprandial hyperglycemia.…”

“…Both require little expertise and allow an individual's risk of having undiagnosed diabetes to be immediately determined so that only those at high risk require a confirmatory diagnostic test. However, the value of risk assessment questionnaires (9–13) and POC glucose analysis (14–16) in resource-poor settings remains unclear. Additionally the performance of these different screening methods has not been compared in rural Asian Indian populations.…”