JANUARY 2013
Venipuncture VS Finger Stick
The Facts and the Fiction
Charles Foltz, Ph.D, M.P.H
Introduction
It’s no secret that biometric screenings are the
foundation to successful wellness programs.
“Good data in, good data out” is critical in
quality,
return
on
investment
and
effectiveness. Deciding on what type of a
screening method to choose can be a
complicated and often confusing choice.
Factors such as testing methods, blood panel
types, accuracy of results and overall company
objectives are just some elements to consider.
In this white paper, we will examine internal
and external studies in a comprehensive
evaluation of the differences, advantages, and
myths of finger stick and venipuncture testing
methods.
Which Screening Method Is More Accurate?
One question often debated in the wellness
industry is whether finger stick is just as
accurate as venipuncture blood testing for
cholesterol screenings. “Accuracy of a Rapid,
Finger Stick Lipid Profile Method is Comparable
to Commercial Laboratory Methods,” a study
commissioned by one of the largest
manufacturers of finger stick equipment, is
commonly referenced by many finger stick
centric companies. The study concluded that
the accuracy of finger stick and venipuncture
screenings is comparable because of biases
seen between both methods. The study‘s
claims, combined with the fact that finger stick
analyzers meet National Education Cholesterol
Program (NCEP) analytical goals, lead people to
believe the methods are comparable.
However, if you take a comprehensive look at
the commissioned study compared with other
studies and measurements seen in a
1 Venipuncture VS Finger Stick – The Facts and the Fiction
practical setting, it becomes clear that there is
NOT a true comparison and that venipuncture
is clearly the most accurate method for
cholesterol screenings.
In the commissioned study, researchers
examined the accuracy of the finger stick
analyzer with three commercial laboratories
by comparing them to true values determined
by a Cholesterol Reference Method
Laboratory Network (CRMLN) laboratory. The
Center for Disease Control (CDC) has
established the CRMLN to ensure the nationwide standardization of lipid measurements
are consistent with the National Education
Cholesterol Program (NCEP) analytical goals.
The NCEP has established total error
guidelines (Fig 1) for lipid tests and the NCEP
guidelines apply to all testing methods
regardless of instrument size or location.
% range
Total cholesterol +8.9%
HDL cholesterol
+13%
Triglyceride
+15%
LDL cholesterol
+12%
Figure 1. NCEP total error guidelines.
To meet the guidelines, blood results from a
device or test must measure within a positive
or negative range at least 95 percent of the
time. For example, if total cholesterol is
measured at 195 by a Cholesterol Reference
Method Laboratory Network (CRMLN)
laboratory, it has met the standard if 95 times
out of 100, the finger stick results fall within a
range of 213 to 178.
The commissioned study claims that finger
stick results are comparable to venipuncture
results because of biases seen in both
www.ehealthscreenings.com Phone: 888.708.8807
methods when compared to the standardized
CRMLN lipid values. Upon closer examination
of the study, the bias shown by LabCorp, the
commercial
laboratory
used
by
eHealthScreenings, was approximately one
percent or less for Total Cholesterol (TC),
Triglycerides (TRG) and Low Density
Lipoprotein Cholesterol (LDL). With such a
small bias, the commissioned study’s claim
that the accuracy of finger stick and
venipuncture are comparable based on biases
when compared to CRMLN values is FALSE if
you only use the LabCorp values.
What did we find when looking at noncommissioned studies?
Non-commissioned studies reveal that finger
stick blood testing does not consistently meet
the NCEP total error guidelines for lipid tests.
In the McKenney et al. study, the total error
assessments indicated that triglycerides and
LDL cholesterol measurements in individual
patients did not meet the guidelines of the
National Cholesterol Education Program and
that more precise measurement technology
for LDL cholesterol is needed. In another
study by Volles et al., they report each device
had an excessive number (12-22%) of
individual results that exceeded NCEP
recommended total error for a single
cholesterol measurement (+/- 8.9%) and both
devices failed to meet the NCEP
recommendation for precision of 3% CV. The
study also states that because of the
variability in results, both devices had
excessive numbers of individual subjects with
total cholesterol results greater than the
recommended total error limit of +/- 8.9%
difference from the standardized method.
At best, there are conflicting reports regarding
whether finger stick blood testing even meets
the NCEP total error guidelines. Even if the
finger stick values read within the acceptable
standards, the variation within the accepted
range could have a significant impact on
employees that are in programs with
incentives and penalties based on results and
progress.
2 Venipuncture VS Finger Stick – The Facts and the Fiction
Referencing the earlier example in which the
Total Cholesterol is determined to be 195 by a
Cholesterol Reference Method Laboratory
Network (CRMLN) laboratory, the finger stick
results need to fall within a range of 178 and
213 to meet NCEP standards. But a reading of
195 versus 213 for total cholesterol is the
difference between low and moderate risk
classification. Also, there are five screenings
that may fall outside the acceptable NCEP
standards of 95 out of 100 times that can lead
to further misclassification of a person’s risk
level. With such a potential for inaccuracy,
employees participating in results based
programs may have viable appeal if finger stick
methods are used instead of venipuncture.
From a clinical perspective, the McKenney et
al. study recommends that physicians and
others who rely on finger stick test results for
diagnosis and treatment decisions should
consider the degree of inaccuracy and
imprecision in these values. In addition, Stein
et al. reports significant variability in lipid
determinations
using
finger
stick
measurements limited their clinical usefulness
in individual patients, and they should not be
used to make clinical decisions regarding the
diagnosis and management of dyslipidemia in
patients.
What did we find when we performed an
internal study?
Shifting from a statistical significance
argument to a practical application scenario,
we examined the reported findings in a
practical setting, with an internal study under
normal screening conditions, examining the
results from finger stick and venipuncture
blood tests. For finger stick testing, we
selected the analyzer that is widely accepted
as the most accurate system for on-site
cholesterol and blood glucose screenings that
was used in the commissioned
study
referenced earlier.
For venipuncture testing, we selected the
national commercial laboratory, LabCorp.
www.ehealthscreenings.com Phone: 888.708.8807
LabCorp is the main laboratory that
eHealthScreenings uses when processing
venipuncture results; based on the
commissioned study, LabCorp is the most
accurate commercial laboratory.
In the study, we tested 36 people who gave
two finger capillary samples that were
analyzed in duplicate on two of six different
analyzers and one venous serum that was
processed by LabCorp nationally. All of the
analyzers were calibrated according to
manufacturer protocols. Only 50 finger stick
and blood test results were used in
calculations based on the number of people
who were fasting and completed both test
methods.
Our findings:
The finger stick results in a practical setting
not only failed to fall within the NCEP
guidelines, they were alarmingly inaccurate.
In addition, there was tremendous variability
between samples on different devices taken
from the same person, bringing into question
the precision of finger stick testing.
Our conclusion is that venipuncture blood
testing is clearly the most accurate and logical
choice for cholesterol screenings based on its
proven accuracy and precision. With most of
today’s wellness programs moving towards
incentive based programming, we believe the
added accuracy is needed to validate the
program. Finger stick screenings may be
better for health fair style screenings where
it’s acceptable to have a ballpark number, but
is NOT recommended for more advanced
wellness programs.
We measured the accuracy of finger stick
testing by comparing each person’s finger stick
results to their venipuncture results. Based on
the extremely low bias for LabCorp reported
by the commissioned study, we used
venipuncture as the gold standard and
calculated the total error of finger stick testing
compared with the NCEP analytical goals. It is
important to mention the commissioned study
did report a high bias for LabCorp’s HDL
measurement.
When we compared the finger stick results
with NCEP total error guidelines, the findings
revealed that none of the blood tests fell
within the guidelines 95 percent of the time.
Finger stick screening met NCEP guidelines for
(Fig 2):
% range
Total
Cholesterol
HDL
Cholesterol
Triglyceride
LDL
Cholesterol
Confidence level
+8.9%
74%
+13%
34%
+15%
72%
+12%
74%
(37 out of 50 times)
(17 out of 50 times)
(36 out of 50 times)
(37 out of 50 times)
Figure 2. Confidence levels
3 Venipuncture VS Finger Stick – The Facts and the Fiction
www.ehealthscreenings.com Phone: 888.708.8807
Now let’s take a look at the pros and cons of both venipuncture and finger stick methods:
Category
Accuracy
Venipuncture
•
•
Testing Panels
•
Pricing
•
Participation
Levels
•
Delivery Of
Results
•
•
Coaching
•
Draw Risk
•
•
•
•
•
ROI
•
•
Data
•
Testing time
•
Participant
Experience
Finger Stick
Most accurate screening method
Reliable measurement tool for validating
results in an incentive based wellness
program
•
•
Abundant testing options including more
comprehensive chemistry panels, lipid
panels, glucose, nicotine/cotinine, PSA,
HbA1c, Thyroid / TSH, CBC, hsCRP,
Homocysteine, and many others
Dependent on the company providing you
with service. For eHealthScreenings,
venipuncture is a much better value
because of the volume of venipuncture
screenings that we process and the
technologies that we are able to use when
facilitating venipuncture events
•
•
Good for general baseline data
Can lead to misclassification of a
participants risk categorization based on
potential accuracy and total error issues
Being “comparable” in accuracy when
compared to venipuncture is not the same
as being just as accurate
Mostly limited to lipid panel and glucose
•
Finger stick screenings have a lot of hard
costs associated with them that can often
increase the price of service. The process
takes longer to complete, the finger stick
cassettes which are used in the devices
are expensive and expire after a month
making it harder to send additional
supplies as any unused are a sunken cost
• The equipment is time consuming to
calibrate adding additional labor time
Participation levels typically have to do with the incentives offered vs the type of screenings
performed
At eHealthScreenings, we typically see better participation with venipuncture
Blood results ready in as little as 1-2
• Immediate results
business days when using
• Value added teachable moment
eHealthScreenings proprietary e.b.i.t
(awareness overview / coaching)
System (encrypted biometric information
transfer). Current industry standard is 7-10
business days
Data accuracy enables coaches to create
• Creates initial awareness
suitable and reliable actionable plans
• Difficult for coaches to determine true risk
geared towards targeting each participants
level because of result inaccuracies
specific areas of concern
Hematoma
• Prolonged tenderness and soreness in
testing finger for up to 3 days after
Slight bleeding
screening
Light headed
• Finger Hematoma
Fainting
• Temporary scaring
Infection (slight risk any time the skin is
• Blood borne infection
broken)
Data accuracy provides a precise target
• Can create initial high-risk awareness
reach which increases ROI through
intervention effectiveness
Advanced panel options allow for
expanded awareness and coaching services
Comprehensive individual lab and detailed
• General awareness report handout
health data reports containing bios and
including bios and blood results
blood results
Approximately 10 minutes per participant
• Approximately 12 minutes per participant
with basic bios
with basic bios
Venipuncture
Finger Stick
Impartial
Method Invasiveness*
43%
50%
7%
Accuracy Confidence*
93%
0%
7%
Method Preference*
93%
7%
0%
Procedure Discomfort*
7%
93%
0%
Procedure Intimidation*
43%
43%
14%
*based on survey results collected from subjects who participated in the conducted internal study.
4 Venipuncture VS Finger Stick – The Facts and the Fiction
www.ehealthscreenings.com Phone: 888.708.8807
So which method is the best choice for your
company?
Simply, the best testing method is predicated
by a company’s wellness objectives.
Venipuncture screenings are ideal when the
wellness program objectives are centered
around:
•
•
•
•
•
•
•
•
•
Quantifiable results
Targeting correct risk factors
Participant incentive program tied to
data
Advanced testing panels
Data Accuracy
High return on investment
Comprehensive participant and
corporate aggregate reports
The participants screening experience
Per participant cost savings
Finger stick screenings are the best choice if
the wellness program is focused on:
•
•
•
Immediate results feedback
Simple baseline data
General awareness
Both testing methods have their respective
places in the wellness industry. With today’s
wellness programs evolving into incentivebased programming, improved accuracy in the
venipuncture method is necessary to validate
the program.
annual basis. Through our core values of
Integrity, Efficiency, Quality, Service, Innovation
and Excellence, we stand behind a steadfast
commitment of delivering total customer
satisfaction.
eHealthScreenings advantages include:
•
•
•
•
•
•
•
Superior service levels
Technology
Speed of data
Pricing
Integration
Customization capabilities
National scalability
For more information about the report or
eHealthScreenings visit
www.ehealthscreenings.com, call 888.708.8807
or email [email protected]
About the author
Charles Foltz Ph.D, M.P.H has over 14 years of
experience in the health and wellness industry.
He completed his doctorate degree in
Interdisciplinary Molecular and Cellular Biology
at Tulane University. In addition, he earned a
Master’s in Public Health in Epidemiology
during his time at Tulane University. Currently,
he serves as the Vice President of Research and
Development at eHealthScreenings.
References
About eHealthScreenings
eHealthScreenings is the nation’s leading
onsite wellness screening company.
We
specialize in the facilitation of onsite biometric
screening services, typically in partnership
with large wellness companies, disease
management
companies,
EAP’s,
HR
consultants, brokers and Third Party
Administrators.
We provided health
screenings for businesses with as few as 25
employees to those where we screen more
than 120,000 employees nationally on an
5 Venipuncture VS Finger Stick – The Facts and the Fiction
McKenney JM, Fary DF, Miller G, Proctor JD, Chinchili
VM. 1993. An evaluation of two compact analyzers
used for lipid analysis. J Fam Pract. 36(5):526-33.
Volles DF, McKenney JM, Miller WG, Ruffen D, Zhang
D. 1998. Analytic and clinical performance of two
compact
cholesterol-testing
devices.
Pharmacotherapy. 18(1):184-92.
Stein JH, Carlsson CM, Papcke-Benson K, Einerson JA,
McBride PE, Wiebe DA. 2002. Inaccuracy of lipid
measurements with the portable Cholestech L.D.X
analyzer in patients with hypercholesterolemia. Clin
Chem. 48(2):284-90.
www.ehealthscreenings.com Phone: 888.708.8807