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

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 (rho=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 >or= 12.2 mmol/L (sensitivity, 83.3%; specificity, 99.3%; positive-predictive value, 95.2%; for a venous value of >or= 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.