Screening for diabetes, impaired glucose tolerance, and cardiovascular risk in primary care: a Northland, New Zealand pilot study.

AIM

To describe the results of a pilot project of diabetes screening in a high risk general practice population.

METHOD

Adequacy of follow-up of fasting plasma glucose (FPG) tests and recording of cardiovascular risk scores was analysed, and the prevalence of diabetes and impaired glucose tolerance (IGT) was calculated using WHO diagnostic criteria.

RESULTS

In a registered population of 28,000, 1251 people were screened for diabetes of which 1129 (90.2%) completed the screening pathway. Diabetes was detected in 3.6% (n=24) of Maori and 2.0% (n=9) of non-Maori. There was no statistical difference between uptake to oral glucose tolerance (OGT) for Maori and non-Maori. Eighty percent (n=1002/1251) of people screened for diabetes had a Cardiovascular Risk Assessment (CVRA). This occurred less frequently in Maori (76.6%, 576/752) compared to non-Maori (85.4%, 426/499), p=0.0001.

CONCLUSION

The consequences of low uptake of OGT ranged from underestimated prevalence estimates to underestimated CVD risk scores. Increased follow-up of raised FPGs is required. Because CVRA uptake was lower in Maori, caution is advised against reliance on CVRA programmes as the sole mechanism to identify Maori with diabetes or IGT. Further investigations into the use of HbA1c as a screening or diagnostic test are recommended for high risk groups.