Cost-effectiveness of point-of-care testing for dehydration in the
Rachel E. Whitney, MD ⁎, Karen Santucci, MD, Allen Hsiao, MD, Lei Chen, MD, MHS
Department of Pediatrics, Section of Emergency Medicine, Yale University School of Medicine, New Haven, CT 06510
Received 6 May 2016
Received in revised form 24 May 2016
Accepted 24 May 2016
Objectives: Acute gastroenteritis (AGE) and subsequent dehydration account for a large proportion of pediatric
emergency department (PED) visits. Point-of-care (POC) testing has been used in conjunction with clinical as-
sessment to determine the degree of dehydration. Despite the wide acceptance of POC testing, little formal
cost-effective analysis of POC testing in the PED exists.
We aim to examine the cost-effectiveness of using POC electrolyte testingvs traditional serum chemistry testing
in the PED for children with AGE.
Methods: This was a cost-effective analysis using data from a randomized control trial of children with
AGE. A decision analysis model was constructed to calculate cost-savings from the point of view of the
payer and the provider. We used parameters obtained from the trial, including cost of testing, admission
rates, cost of admission, and length of stay. Sensitivity analyses were performed to evaluate the stability of
Results: Using the data set of 225 subjects, POC testing results in a cost savings of $303.30 per patient com-
pared with traditional serum testing from the point of the view of the payer. From the point-of-view of the
provider, POC testing results in consistent mean savings of $36.32 ($8.29-$64.35) per patient. Sensitivity
analyses demonstrated the stability of the model and consistent savings.
Conclusions: This decision analysis provides evidence that POC testing in children with gastroenteritis-related
moderate dehydration results in signiﬁcant cost savings from the points of view of payers and providers com-
pared to traditional serum chemistry testing.
© 2016 Elsevier Inc. All rights reserved.
Few ﬁelds of practice are as consistently innovative as the practice of
medicine. New technologies of diagnostics and treatments are frequent-
ly introduced into practice with the hope of improving patient care. The
costs of these changes, however, are not always examined before imple-
mentation. The ideal new technology is one that supports a low-
spending/high-performance hospital system . Point-of-care (POC)
testing for serum electrolytes allows accurate and rapid results at a re-
duced cost compared with traditional laboratory testing .Thistech-
nology can be especially useful in the emergency department (ED),
where previous research has shown that the use of POC testing leads
to decreased time to medical decision making  and decreased length
of stay (LOS)  in select populations.
Acute gastroenteritis (AGE) accounts for almost 2 million annual
visits to pediatric emergency departments (PED) in the United States
and incursa large health care cost. App ropriate treatmen t of children
with dehydration from AGE requires assessment of severity of symp-
toms and degree of dehydration.Often, the degreeof dehydration deter-
mines treatment course and disposition, that is, admission vs discharge
and oral vs intravenous hydration . Although weight loss is accepted
as the most accurate method of determining degree of dehydration, this
is not always possible to determine in the emergency setting, where a
recent prior weight is usually not available. Consequently, other factors
are used to judge the severity of dehydration. These factors often in-
clude serum electrolyte measurements .
We aim to examine the cost-effectiveness of using POC electrolyte
testing vs traditional serum chemistry testing in the PED for children
with AGE. We predict that use of POC technology for AGE management
results in a cost savings from the points of view of the payer as well as
American Journal of Emergency Medicine 34 (2016) 1573–1575
☆Fundingsource: This researchdid not receive any speciﬁcgrant from fundingagencies
in the public, commercial, or not-for-proﬁt sectors.
☆☆ Financial disclosure: The authorshave no ﬁnancial relationshipsrelevant to this article
★Conﬂict of interest: The authors have no potential conﬂicts of interest to disclose.
⁎Corresponding author at: 100 York St, Suite 1F, New Haven, CT 06511. Tel.: +1 203
E-mail address: firstname.lastname@example.org (R.E. Whitney).
0735-6757/© 2016 Elsevier Inc. All rights reserved.
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American Journal of Emergency Medicine
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2.1. Decision analysis
We calculated the incremental cost-effectiveness using data from a
randomized controlled trial of children with AGE . A model was con-
structed using parameters obtained in the trial, including cost of testing,
admission rates, and cost of admission (Figure). We performed the anal-
ysis from 2 points of view. First, we calculated costs based on the point
of view of the payer. Next, we looked at costs from the point of view of
the provider (ie, the hospital system). Cost data were obtained from var-
ious reference sources (Table).
2.2. Equipment costs
The POC device used for this study was the i-Stat Analyzer (Abbott
Point of Care, East Windsor, NJ), a handheld, cartridge-driven device ca-
pable of performing basic electrolyte and blood gas tests in less than 2
minutes. Each cartridge requires less than 0.1 mL of blood. Tests used
during the course of the study included basic electrolytes (sodium, po-
tassium, chloride, and bicarbonate), glucose, blood urea nitrogen, creat-
inine, ionized calcium, hematocrit, and basic blood gas analysis. The cost
of an i-Stat 7 cartridge to the payer is $8.59. These data were obtained
from our university health center.
A basic metabolic panel, which includes sodium, potassium, chlo-
ride, bicarbonate, blood urea nitrogen, creatinine, and calcium, costs
the payer $11.54 and has a result time of 1 hour for STAT orders and 4
hours for routine orders. These data were obtained from our university
2.3. Payer costs
We used an average admission cost of $1158.76 per day for an oth-
erwise healthy patient admitted for dehydration in the setting of AGE
(unpublished hospital data). We then multiplied this cost by 2.16
days, the average LOS for AGE admission at ouruniversity health center
(unpublished data), for a total admission cost of $2502.92. The cost and
LOS are on par with data from Pediatric Health Information System
(PHIS) data. The total cost of the hospital stay was multiplied by the
probability of admission for patients in the POC and serum testing
groups . Cost data were obtained from our university health center.
The sentinel PED visit was not included in the cost. All costs are
expressed in US dollars.
2.4. Provider costs
We calculated the opportunity cost for the hospital based on de-
creased LOS in the POC group as measured by nursing hours saved.
The hourly wage for nursing staff in our university ED ranges from $35
to $70 per hour, based on experience and speciﬁc shift. The median
LOS for the POC group was 38.5 minutes, 95% conﬁdence interval
(14.3-55.0), shorter than the traditional serum testing group.
2.5. Sensitivity analysis
We performed 1-way sensitivity analyses to determine the stability
of our model. We used the 95% conﬁdence interval cutoffs  for ED
LOS, varied the rate of admission by 20% bidirectionally, and used the
low and high range of nursing salary.
From the point of the view of the payer, the average cost per patient
using iSTAT was $784.48. The average cost using serum electrolytes was
$1087.78. Results of our decision model suggest that using POC testing
rather than traditional serum testing results in a cost savings of
$303.30 per patient (Figure). Sensitivity analysis for admission rate
shows stability of the model and consistent savings. Varying admission
rate by 20% bidirectionally gives a savings range of $225.99 to $378.40.
From the point-of-view of the provider, the time saved with POC
testing factored by average nursing salary shows a mean cost savings
of $33.60 per patient. Performing the sensitivity analysis with low and
high range of nursing salaries, the savings had a range of $8.40 to
$64.40 per patient.
Figure. Cost to individual payer in POC and serum testing groups.
Hypothetical cohort of 100 patients in each arm.
Probability of admission and discharge in each arm as calculated by
Hsiao et al .
Assumptions for decision analysis
Assumption Rate Reference
i-Stat cost $8.59 University data
Serum cost $11.54 University data
Admission cost $1158.76 PHIS data
Admission LOS for AGE 2.16 d PHIS data
Admission rate for i-Stat testing 31% Hsiao et al
Admission rate for serum testing 43% Hsiao et al
Nursing hourly wage range $35-70/h University data
ED LOS difference for i-Stat group 38.5 min/patient Hsiao et al
1574 R.E. Whitney et al. / American Journal of Emergency Medicine 34 (2016) 1573–1575
Although widely studied in adult populations, scant data exist on
cost-effectiveness for POC testing in the pediatric population. We have
shown that using POC testing rather than traditional serum testing for
children presenting with gastroenteritis may result in cost savings
from the points of view of the payer as well as the provider.
The American Academy of Pediatrics set weight measurement as the
standard of dehydration assessment . However, this parameter con-
tinues to be debated , and several measures have been offered as ad-
junct evaluation tools .Perhaps,mostwidelysupportedinliterature
is electrolyte testing to help evaluate degree of dehydration in children.
Although conﬂicting results exist for blood urea nitrogen and creatinine
as markers for dehydration, bicarbonate is consistently shown to be de-
creased in moderate to severe dehydration [10,12,13] with a cutoff
value of less than 15 to 17 mmol/L indicative of moderate to severe de-
hydration [7,14,15]. These laboratory markers, in addition to the overall
clinical picture of the patient, are often incorporated to determine the
need for intravenous hydration. Given that earlier result time has been
linked to decreased time to medical decision making , it is possible
that intravenous ﬂuids were started earlier and more appropriately in
the POC testing group.
Our data also show that use of POC testing can lead to decreased cost
for the hospital by decreasing LOS and creating revenue potential
through bed and nursing availability. Decreased LOS and time to treat-
ment with use of POC testing have been shown consistently in adult
populations [4,16,17]. The same properties lead to increased through-
put and bed turnover in pediatric patients, as demonstrated in the
study by Hsiao et al .
Our decision model is based on data from a single randomized con-
trol trial set in an urban tertiary care children's hospital and is therefore
not necessarily generalizable to all PED settings.
A major contributor to overall cost savings in our model was the de-
crease in admission rates for the POC testing group. Admittedly, this is
not a consistent ﬁnding in theavailable literature. One possible explana-
tion for this is that shorter time to institute appropriate treatment based
on laboratory data leads to more prompt improvement in clinical condi-
tion during the ED stay, thereby leading to decreased admission rates.
The cost data for laboratory testing and result time for testing are spe-
ciﬁc to our university health center. The relatively small sample size of the
randomized control trial model tempers our conclusions. The original
study was performed before the widespread availability of low-cost ge-
neric ondansetron . As previously mentioned, cost savings from the
hospital perspective is subject to numerous variables that affect bed avail-
ability and nursing hours. Although this is challenging to quantify, deci-
sion model analysis has been proven as a reasonable assessment tool,
and our cost-savings results were found to be consistent after careful sen-
This decision analysis provides evidence that POCtesting in children
with moderate dehydration from gastroenteritis results in signiﬁcant
cost savings from the points of view of payers and providers.
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