Screening blood donors for diabetes: analysis of use, accuracy, and cost

The objective was to determine if a free, voluntary diabetes screening program as a part of the blood donation process might be cost-effective.

During the first 6 months of the program, 26,415 donors were screened using a single random plasma glucose (RPG) level. All donors were asked to eat before donation. Low-, moderate-, and high-risk groups were formed based on RPG levels (<140, 140-200, and >200 mg/dL). Contact with a telephone questionnaire was made with 139 of 178 (78%) of the persons in the high-risk group with 33 new cases of diabetes diagnosed by the donor's physician and 26 donors indicating that they were not diagnosed with diabetes. Sex- and age-matched donors in the low- and moderate-risk groups were contacted and administered the same questionnaire.

The three risk groups were similar, except for body mass index (28.1 ± 5.4 kg/m2 vs. 29.9 ± 5.5 kg/m2 vs. 32.7 ± 5.6 kg/m2 , p < 0.001). The discriminative effectiveness of screening was evaluated by the area under the receiver operating characteristics (AROC) curve. The AROC curve was 0.950 (95% confidence interval, 0.920-0.979) for the identification of diabetes. Using a RPG cutoff of 200 mg/dL, sensitivity was 100%, specificity was 82%, and positive predictive value was 56%. Cost analyses showed that the mean cost to screen, per donor, was less than $1. Cost per case identified was estimated to be less than $500 for a RPG cutoff of 200 mg/dL.

Screening during the blood donation process appears to be accurate, convenient, and inexpensive.