Acceso usuarios
Objective. To analyse the validity of the Micraltest and Microbumintest semi-quantitative methods for microalbuminuria screening in type 2 diabetes mellitus in primary care clinics.
Design. Crossover study to validate diagnostic tests.
Setting. Three general practices at an urban health centre.
Patients. Consecutive sample of 64 diabetics not dependent on insulin.
Measurements and main results. Each patient's own doctor performed in the consultation the semi-quantitative determinations in a simple sample of the morning's first urine. As standard, a rate of albumin excretion above 20 µgr/min, determined by immunonephelometry in a 2-hour controlled time sample, was used. The prevalence of Microalbuminuria was 25% (C.I. 95%, 14.4-35.6). The sensitivity of Micraltest was 69% (CI, 42-88), and its specificity 52% (CI, 37-67), corresponding to the cut-off point of 10 mg/L. The sensitivity of Microbumintest was 63% (CI, 36-84), and its specificity 67% (CI, 52-79). The combination of both tests in one sample had 75% sensitivity (CI, 47-92) and 44% specificity (CI, 30-59). Negative predictive values ranged between 84 and 85%.
Conclusions. The semi-quantitative microalbuminuria detection tests are of limited use in the primary care clinic. Their sensitivity and the negative predictive value obtained in an isolated sample do not seem acceptable for a screening method.
