A comparison of chromogen test strip (Chemstrip bG) and serum glucose values in newborns
P. C. Holtrop, K. A. Madison, F. L. Kiechle, R. E. Karcher and D. G. Batton
Department of Pediatrics, William Beaumont Hospital, Royal Oak, MI 48072.
Although glucose oxidase-peroxidase chromogen test strips are frequently
used to estimate serum glucose values in newborns, previous studies have
not evaluated multiobserver variability of test strip readings and have
included few infants with hypoglycemia. We compared values of 272 samples
of serum glucose with values simultaneously obtained by chromogen test
strips (Chemstrip bG) in newborns. The diagnostic sensitivity of a
chromogen test strip less than 2.2 mmol/L for predicting a serum glucose
level less than 1.9 mmol/L was 86% (95% confidence interval [CI], 75% to
94%), with 78% specificity (95% CI, 73% to 84%). The positive predictive
value in our specimens, with a 21% prevalence of serum glucose levels less
than 1.9 mmol/L, was 52% (95% CI, 41% to 62%), with a negative predictive
value of 95% (95% CI, 91% to 100%). Fifty-eight of our serum glucose values
were less than 1.9 mmol/L and the levels obtained by chromogen test strip
were greater than or equal to 2.2 mmol/L in 8 of these cases. Review of
these 8 cases showed that a delay in performing the laboratory glucose
oxidase serum glucose could account for the discrepancy in 2 cases.
Chromogen test strips are readily available and easy to use, but more
sensitive, specific, accurate, and precise methods of serum glucose
screening in newborns are needed.