QUALITY ASSESSMENT OF BLOOD-GLUCOSE TESTING IN GENERAL-PRACTITIONERS OFFICES IMPROVES QUALITY

Measurement of blood glucose is a frequent lest in Danish physicians' offices. We describe here a new design of external quality assessment wherein fresh, unstabilized whole-blood samples were analyzed by tile physicians' office methods and by a hospital laboratory comparison met hod (glucose dehydrogenase assay, calibrated against NIST 909a). This approach was used in the offices of 171 general practitioners in our c ounty during a 5-year period. The first survey, in 1992, revealed unsa tisfactory performance in terms of our criterion that no difference be tween the physician's office and the hospital laboratory's single resu lt should exceed +/-20% of the laboratory result. After initiation of a program of consultation and assistance, tile proficiency testing rou nds of 1994 and 1996 showed considerable improvement. Thus, whereas in 1992 12% of the values were outside the acceptance limits, in 1994 an d 1996 the respective values were 4% and 3%. We believe the effect was mainly related to improvements Ift choice of technology, procedures, and handling oi: specimens, We conclude that the use of bedside instru ments should be restricted to diagnosis of only severe hypo-or hypergl ycemia and to monitoring glucose >5 mmol/L in already diagnosed diabet ics. Our program differs from previous approaches to duality assessmen t and could also be useful for large hospitals' in-house proficiency t esting.