sBMJ | Blood tests: essential or excessive?

Blood tests: essential or excessive?

Perhaps one of the most widely used medical investigations is the humble blood test. Or is it quite so humble? As a medical student, I took a part time job taking blood as a phlebotomist at my local district hospital. Often the perception amongst phlebotomists is that blood tests become the addictive habit of newly graduated nervous doctors. Weekend requests are apparently “urgent only.” Yet, with 17 requests a ward on a Sunday morning, you wonder how many of the results will even be reviewed. Surprisingly, we find that “extremely urgent” patient X has gone home, or “very seriously sick” patient Y has gone for a morning walk.

Blood tests are important in clinical practice. But is it possible to put a little more thought into requesting tests? Apart from some phlebotomist agitation, there are important factors at stake. In fact, unnecessary testing may cause significant reduction in blood volume in critically ill patients.¹

Although blood tests are considered to be cheap, overuse of any service may lead to adverse financial and practical outcomes. Some may argue that this is little cause for concern. Surely it is more sensible to prevent a problem, especially when overuse of this facility is easy to avoid. It would reduce workload and benefit patients. Explanations for excessive testing include inexperience; poor understanding of the basis, sensitivity and specificity of tests; and fear of litigation.² Requesting blood tests tends to be the responsibility of junior doctors and is therefore relevant to the next generation of doctors.

Overall, UK laboratories continue to see a rise of 5-10% each year in requests for laboratory tests.³ Individually they are relatively cheap, but, as shown, the cumulative cost is considerable. Several studies have shown that between 25% and 40% of all tests sent to the laboratory are unnecessary.³

The financial implication is only one aspect of this potential problem. As medical students, we learn that 80% of diagnoses result from clinical history and examination. But, in practice, how many of us would proceed with management without confirmation from the numerous investigations available to us today? It can be argued that requesting investigations without consideration may affect our clinical skills. In reality have we become more confident in tests than in our own clinical judgment?

MAURO FERMARIELLO/SPL

Blood tests are a simple way of gaining clinical information but tend to become invasive and expensive when done excessively. Consider the reasons behind requesting the tests and whether they will help you to manage your patient.

I thank the phlebotomy staff at Leicester General Hospital.

Neha Sharma, fifth year medical student, University of Leicester
Email: ns84@le.ac.uk

studentBMJ 2006;14:265-308 July ISSN 0966-6494

McPherson RA. Blood sample volumes: emerging trends in clinical practice and laboratory medicine. Clin Leadersh Manag Rev 2001;15:3-10.
Axt-Adam P, Johannes C, Van der Wouden MA. Influencing behaviour of physicians ordering laboratory tests: a literature study. Med Care 1993;31:784-94.
Newchurch. National pathology alliance benchmarking report 2000/1. London: Newchurch, 2002.

Responses published this month

Articles	Responses
REVIEWS Blood tests: essential or excessive? Neha Sharma (July 2006)	Dr. Parineetha P Bhat (July 10th, 2006) Read this response

REVIEWS Blood tests: essential or excessive? Neha Sharma (July 2006)	Dr. Raghesh varot kangath (August 19th, 2006) Read this response

	REVIEWS Blood tests: essential or excessive? Neha Sharma (July 2006)
	Dr. Parineetha P Bhat (July 10th, 2006) Assistant Professor,Department of Biochemistry,Melaka Manipal Medical College (Manipal Campus),Karnataka, India drparibhat@yahoo.com
	Laboratories have long made an important contribution to improve patient outcome.If looked from a cost-effectiveness point of view, there may well be unnecessary information present.This can be changed, if laboratorians participate in a process which prospectively determines the true value of laboratory information and how constructive changes and constraints can improve the its overall effectiveness.In practice, the laboratory may be overutilized, underutilized,or malutilized-each contribute to an increase in costs.Laboratory testing is an intermediate and not a final outcome, meaning that the information provided is used as a means to a subsequent action (like diagnosis or management of a disease).Physicians, thus, control utilization of laboratories.Use of appropriate requisition slips may help a lot on the choice of tests. Coordinated effort of many individuals and many hospital departments may help in accomplishing this goal.Peer review audits may lead to the development of guidelines concerning the appropriate use of diagnostic tests in different clinical situations. Careful monitoring of test requests and their appropriatness is needed to be done by laboratrians, and this should form the basis for inservice education to effect changes in ordering patterns.

	REVIEWS Blood tests: essential or excessive? Neha Sharma (July 2006)
	Dr. Raghesh varot kangath (August 19th, 2006) MBBS, 98, Dr.SMCSI Medical college Hospital, Karakonam. drraghesh@yahoo.com
	The article rightly points to the issue of overuse of blood investigations in routine clinical practice. Even patients admitted for mild ailments have to undergo almost every blood investigation used in clinical practice. My opinion is that the blood investigations are useful to a certain extent eventhough it causes a lot of inconvenience to the patient and is risky nowadays with the high prevalence of blood borne infectious diseases. The other side of the issue is that the hospital admission provides a wonderful opportunity to diagnose many of the impending disease conditions like boderline blood sugar values indicating higher risk of diabetes and mild hyperlipedemia predisposing to heart diseases. Thus many of the grave outcomes of various diseases can be avoided. Also during acute illnesses which the patients usually present with, the stress alters certain hematological parameters like fasting glucose (increases) and haemoglobin(decreases). This stress reaction again is a helpful aid in the future follow up of the patients.