Abstract:
Blood glucose level is the most frequently
analyzed parameter in a routine clinical laboratory
in order to assess diabetes mellitus. Currently,
commercial reagent kits with high costs are used for
this test. However, the same reagent can be prepared
in the laboratory at a lower cost. The aim of this
study was to examine the performance of an in house reagent method under standard laboratory
conditions with the analyzer specific commercial
glucose reagent. An evaluation study was carried out
at the Clinical Pathology Laboratory, Teaching
Hospital, Karapitiya using 200 randomly selected
retained blood samples. Glucose values were
determined by in-house glucose reagent and
commercial glucose reagent. Correlation and the
agreement between the two methods were
determined. Accuracy, sensitivity, specificity,
precision, and stability was checked for the in-house
method. Daily IQC and monthly EQA samples were
run to assure precision and accuracy. The results
were significantly correlated (r=0.9993; p=0.001),
and the two methods indicated a good agreement
with a positive bias of 0.835±0.488 mg/dL in Bland
Altman analysis. There was a good agreement
between 0-300 mg/dL. At concentrations above 300
mg/dL, a tendency towards increasing scatter was
observed, which could be due to the low number of
sample size in this range. Accuracy, sensitivity, and
specificity were 96.5%, 96.15% and 97.14%
respectively. The in-house method was linear up to
1000mg/dL. An intra-assay precision (CV) of 6.88
and 2.38% and an inter -assay precision of 2.21 and
3.34% were obtained for normal and high levels of
glucose respectively. The reagent was stable for a
period of three months at 2-8˚C.The in-house glucose
reagent is more cost-effective and possesses similar
performance characteristics and good stability,
compared to the analyzer specific glucose reagent.
Thus, it can be adopted for analysis of plasma
glucose in routine laboratory checkups.
