Opportunistic screening for diabetes in general practice is better than nothing

EDITOR—Lawrence et al conclude in their paper that screening for diabetes in general practice by measuring fasting blood concentrations of glucose has a very low yield in patients whose sole risk factor for diabetes is age 45 or more.1 Our experience from opportunistic screening in a rural primary health centre in Sweden is different.

A sign in the waiting room during 1999 invited all visitors aged 40 or older at the centre in Storvik, a village of 6800 inhabitants, to have their blood concentrations of glucose tested. Altogether 249 patients accepted, of whom 72 had a non-fasting capillary blood concentration of glucose of >6.7 mmol/l.

The latter group was invited to return for two further tests. Sixty two showed up, and 18 of these had a capillary blood concentration of glucose of >6.1 mmol/l in both tests. 2 3 Five were aged around 50, and eight were aged 75 or older. Altogether 349 tests were performed. The cost of materials and work per test was about £2.00.4

Thus we found 18 new diabetic patients at very low cost by opportunistic screening. Our screening method was simple: £40 to find a diabetic patient, or about £140 per person to find these five “younger” patients, is a low cost. To set the cut-off point for a normal random blood concentration of glucose to <6.7 mmol/l is said to give a sensitivity of 64% …