Cost containment and labor-intensive tests. The case of the leukocyte differential count
M. F. Shapiro, R. L. Hatch and S. Greenfield
We conducted an analysis of the use of the leukocyte differential count to
determine (1) the services ordering the largest numbers of tests, (2) the
proportion of differentials that were clinically justifiable and useful,
and (3) the potential for real cost savings as opposed to reduction in
charges if unjustified differentials could be eliminated. The sources of
all laboratory requisitions during three nonconsecutive weeks were
determined; criteria for test justifiability were established; an audit of
a random sample of medical records was conducted on two services obtaining
the most tests; and a time-motion study was undertaken in the hospital
hematology laboratory. Forty-seven percent of differentials were obtained
on medical and surgical inpatients and only 10% in the medical clinics.
Forty-eight percent and 62% of differentials on the medical and surgical
services, respectively, were unjustifiable , making up 26% of all
differentials done in the hospital laboratory. Test results appear to have
affected patient management in less than 3% of patients; no unjustified
test altered a patient's diagnosis or therapy. Elimination of only
"unjustified" medical and surgical differentials would permit a reduction
of 1.8 full-time equivalent positions from the hospital laboratory. The
leukocyte differential is over-used, only occasionally useful, and amenable
to real cost reduction.
