Cross-sectional comparison of point-of-care with laboratory HbA₁c in detecting diabetes in real-world remote Aboriginal settings.

objectivesTo determine if point-of-care (POC) glycated haemoglobin (HbA₁c) is sufficiently accurate in real-world remote settings to predict or exclude the diagnosis of diabetes based on laboratory HbA1c measurements.

designCross-sectional study comparing POC capillary HbA₁c results with corresponding venous HbA₁c levels measured in a reference laboratory.

participantsAboriginal patients ≥15 years old who were due for diabetes screening at the participating clinics were invited to participate. Two hundred and fifty-five Aboriginal participants were enrolled and 241 were included in the analysis.

setting6 primary healthcare sites in the remote Kimberley region of Western Australia from September 2011 to November 2013.

main outcome measuresConcordance and mean differences between POC capillary blood HbA₁c measurement and laboratory measurement of venous blood HbA₁c level; POC capillary blood HbA1c equivalence value for screening for diabetes or a high risk of developing diabetes; sensitivity, specificity and positive-predictive value for diagnosing and screening for diabetes; barriers to conducting POC testing.

resultsConcordance between POC and laboratory results was good (ρ=0.88, p<0.001). The mean difference was -0.15% (95% limits of agreement, -0.67% to 0.36%). POC HbA₁c measurements ≥6.5%, 48 mmol/mol had a specificity of 98.2% and sensitivity of 73.7% for laboratory measurements ≥6.5%. The POC equivalence value for screening for diabetes or a high risk of developing diabetes was ≥5.7%, 39 mmol/mol (sensitivity, 91%; specificity, 76.7% for laboratory measurements ≥6.0%, 42 mmol/mol). Staff trained by other clinic staff 'on the job' performed as well as people with formal accredited training. Staff reported difficulty in maintaining formal accreditation.

conclusionsPOC HbA₁c testing is sufficiently accurate to be a useful component in screening for, and diagnosing, diabetes in remote communities. Limited local training is adequate to produce results comparable to laboratory results and accreditation processes need to reflect this.