Claims made for the value of laboratory medicine, and their evidence base:
"60-70% of NHS patients' diagnoses depend on laboratory tests"
This seems to be confined to DH sources. Thanks to Dennis Huckerby for finding the
first published reference, in the First Report of the House of Commons Select
Committee on Health (published 1 May 2002):
http://www.parliament.the-stationeryoffice.co.uk/pa/cm200102/cmselect/cmhealth/308/30801.htm
141. Up to 70% of all diagnoses in NHS patients depend on laboratory tests, hence NHS pathology services
are critical for the day to day evidence-based care of patients.
I cannot find the source for this statement in any of the supporting material for the
First Report, and (as Mike Colley has pointed out) “up to 70%” is not very definite.
“60-70%” is stated - unreferenced - in Modernising Pathology Services (DH
publication 34284, 2004). This is the best citation (if you really must cite it!!).
http://www.dh.gov.uk/en/Publicationsandstatistics/Publications/PublicationsPolicyAn
dGuidance/DH_4073106
However, I can find no evidence for it, and common sense suggests that if you
consider all NHS diagnoses (including primary care, mental health etc) it must be
wrong. I think it derives from a misquotation/misunderstanding of the second
statement, and confidential comments from those closely involved at the time of
inception of the Pathology Modernisation Project have supported this view. It is
perhaps time that this extreme form of the claim was quietly buried.
"60-70% of all critical medical decisions depend on laboratory data"
This much more circumspect claim is made in a 1996 paper from the Mayo Clinic
(Forsman RW, Clin Chem 1996: 42: 813-816, p813). The paper actually says
"We know that, although the laboratory represents a small percentage of medical
center costs, it leverages 60-70% of all critical decisions, e.g. admission, discharge
and therapy". - although it does not say how we know that!
I have emailed Rodney Forsman to ask for the evidence behind it. He kindly provided
the following article from Clinical Laboratory News (July 2004):
Communicating the Laboratory’s Value to Health Care
An Interview with Rodney Forsman
Getting clinicians, insurers, consumers, and others to appreciate and understand the magnitude of the
contribution clinical laboratories make in providing and improving health care is not a new problem.
Historically, clinical laboratories haven’t ranked high on hospitals’ priority lists at budget time, and
throughout the ‘90s, labs struggled to make managed care organizations understand that lab services
were not commodities that could be sold to the lowest bidder.
How can laboratorians better communicate the value laboratories bring to health care, and what can be
done to attract new laboratorians into the field? Clinical Laboratory News asked Rodney Forsman,
Administrative Director of Outcomes at Mayo Collaborative Services, Inc., in Rochester, Minn., to
share his thoughts on these topics. During his 30 years working in various capacities for the Mayo
Clinic’s Department of Laboratory Medicine and Pathology, Forsman has delivered over 175 lectures
to national and regional professional meetings throughout the U.S. on the subjects of health system
integration, laboratory outreach, quality improvement, regulatory issues, and managed care strategies.
He has over 40 publications on scientific and management topics and is frequently quoted in
laboratory news periodicals.
CLN:
The statement, “Seventy percent of medical decisions are based on laboratory test results,” or some
similar statement is frequently quoted by laboratorians in an effort to provide an objective picture of
the value laboratory testing brings to clinical decision making. Your Clinical Chemistry article from
the proceedings of the AACC 1995 Clinical Chemistry Forum, called “Why is the laboratory an
afterthought for managed care?” has been cited as the source of this quote. Can you explain where the
data came from?
Forsman: Actually, the statements that have been made take two forms. The first is that the
laboratory represents 5% of a health system’s costs, yet it affects 95% of the remaining costs. The second statement is that the laboratory contributes 80% of the objective data in the clinical record and
influences 60%–70% of critical decision making. Unpublished sources for these statements include
conversations with Dr. Peter Dysert at Baylor University in Houston, Texas, and Dr. Michael Becich
at the University of Pittsburgh. The first mention I made of this notion was stated in a presentation at
an AACC conference and published in the 1996 Clinical Chemistry article. I attempted to substantiate
this with data from our own electronic medical record and actually found that 94% of the objective
data in the Mayo electronic medical record was from the laboratory. Also we have a “hit rate” of
nearly 200,000 inquiries on this information daily with the implication that the information is being
used. This was reported in two separate articles in 2000 and 2002 in Clinical Leadership and
Management Review (2000;14:292–295), (2002;16:370–373).
CLN:
This quote has been used extensively in talks at numerous laboratory conferences. Is it being used in
the manner which you intended?
Forsman: I was called a few months ago by a reporter from Glamour magazine, and she was
checking the accuracy of the quote to see if her source had the information right. I had to tell her, no,
that they had drawn too much from it. They were trying to say that laboratory information is the only
thing used in diagnosis 60%–70% of the time. Of course, that’s not true. It’s one part of a whole
spectrum of information that comes together in a patient care setting to make a diagnosis or treatment
decision, discharge, and all of the other downstream things associated with health care.
Not massively convincing, in my view. I have emailed Mike Becich (who is quoted as
an unpublished source) for his comments but have not yet received a reply.
A variant of this statement occurs in the first Carter report (Report of the Review of
NHS Pathology Services in England (2006):
http://www.dh.gov.uk/en/Publicationsandstatistics/Publications/PublicationsPolicyAn
dGuidance/DH_4137606
"It is estimated that 70-80% of all health care decisions affecting diagnosis or
treatment involve a pathology investigation" (para 1) - but NB the loss of the word
'critical' and the increased percentage! No evidence is quoted.
Intuitively, this form of the statement sounds right, but again hard evidence is
lacking. Much will depend on how you define a ‘critical medical decision’, as Rick
Jones has pointed out.
“We need a much more rigorous approach to understanding the types of decisions and the
impact of different tests in each context. Then we might be able to work up strategies to ensure
that where decisions are dependent on results we can provide them in an optimal way and where
they make no difference we can stop wasting money.”
"70-80% of the electronic medical record (EMR) consists of laboratory data"
This is much the best supported of the three statements, though published
percentages do vary widely, and it is not exactly a ringing endorsement of the value
of what we do, being a “never mind the quality – feel the width” sort of argument.
As Roger Bertholf points out:
“The amount of space that a particular piece of information occupies in the medical
record does not necessarily correlate with its importance. I would suggest that a
pathological diagnosis of malignancy in a biopsy report takes up relatively little space
in the EMR, but is likely to have a profound effect on treatment.”
Well said. However, for what it is worth…
The data from the Mayo Clinic is referred to in the CLN article above – “94% of the
objective data” in the Mayo EMR coming from the lab (thanks to Leslie Burnett for
also providing this statistic). The Clin Leadership Management Review articles cited
in support are not available on the web, so I haven’t been able to look at the details,
and find out exactly what they mean by “objective data”.
Paul Collinson finds this, from
Bradshaw KE, Gardner RM, Clemmer TP et al. Physician decision-making--evaluation of data used in a
computerized ICU. Int.J.Clin Monit.Comput. 1984;1:81-91.
New instrumentation, techniques and computers have made such large amounts of information
rapidly available to ICU clinicians that there is now a danger of information overload. To help with
this problem at LDS Hospital, a computerized system was implemented in the Shock-Trauma
ICU. This ICU is almost totally computerized with each patient's physiologic, laboratory, drug,
demographic, fluid input/output and nutritional data integrated into the patient's computer record.
In the ICU, physician decision-making takes place in two situations: during rounds and on-site.
For this study, data usage in decision-making was evaluated in both of these environments. The
items of data used in decision-making were tabulated into six categories: bedside monitor,
laboratory, drugs, input/output and IV, blood gas laboratory, observations and other.
Comparisons were made between the portion of the computerized database occupied by a
category and its use in decision-making. Combined laboratory data (clinical, microbiology and
blood gas) made up 38 to 41% of total patient data reviewed and occupied 16.3% of the
database. Observations made up 21-22% of the data reviewed and occupied 6.8% of the
database. Drugs, input/output and IV data usage ranged from 13% to 23%, but occupied 36% of
the database. Bedside monitor data usage was 12.5% to 22% and occupied 32.5% of the
database. The 'other' category, used 2.5% to 5% of the time, made up 8.4% of the database.
These results indicate that patient data collection and storage must be evaluated and optimized.
This evaluation, along with implementation of the computerized ICU Rounds Report developed
for optimal data presentation, will help physicians to evaluate patient status and should facilitate
effective decisions
- a much lower percentage but quite an old paper.
and Mike Collins finds this from the Dark Report:
Finally, another useful nugget. Around 2002, after Aurora Health
Systems of Milwaukee had implemented an electronic medical record
system (EMR), the Chair of Pathology, Jay Schamberg, M.D., spoke at the
Executive War College meeting that year. He stated during his
presentation that, after converting patient files to the EMR, his IT
department had determined that the average permanent patient electronic
health record contained lab test data/information that totaled about
82% of the total data bits used to story the patient's full health
record. This statistic maps to the oft-used statement that about 70% of
a patient's permanent health record consists of laboratory test data.
Many thanks to all who helped by providing information! I’ll let Dilbert have the last
word.
Mike Hallworth
July 2011