The use of clinical laboratory test results in diagnostic decision-making is an integral part of clinical medicine. The menu of laboratory tests available to clinicians constitutes an impressive array that has expanded exponentially since 1920 when Folin and Wu devised the first useful test for the quantification of serum glucose concentration. Despite this ever-expanding plethora of useful and reliable clinical laboratory tests for diagnosing and monitoring the myriad of diseases effecting mankind, the recent emphasis on reducing health care costs and the emergence of managed care organizations led to efforts to reduce the abuse (over-ordering) and misuse (e.g., ordering the right test for the wrong purpose or vice versa) of these tests.
Every laboratory test has a component of errors and the majority of laboratory errors occur during the requesting and collection of specimens, and in the reporting and application of results. If we look at the matters with lack of Time and poor abilities to differentiate the clinical disorders many tests are ordered as random way to fish the matters in the deep seas. Every test ordered without proper clinical decision making have a adverse consequences and economic loses
Questions to Ask Before Ordering a Laboratory Test
An understanding of which laboratory tests are appropriate to order in the diagnosis and follow up of a patient’s medical condition should include prior consideration of the answers to the following questions:
• Why is the test being ordered?
• What are the consequences of not ordering the test?
• How good is the test in discriminating between health versus disease?
• How are the test results interpreted?
• How will the test results influence patient management and outcome?
Many serological tests are today ordered as a habit to many patients. The laboratory should establish the sensitivity and specificity of the tests and it is important to note that any test with a sensitivity = 50% and a specificity = 50% is no better than a coin toss in deciding whether or not a disease may be present. Tests with a combined sensitivity and specificity total = 170 or greater are likely to prove clinically useful. Most clinicians can achieve this total with a good history and physical examination! Thus, a laboratory test with 95% sensitivity and 95% specificity (sum = 190) is an excellent test.
Today our Physicians need to know the basis of laboratory tests and have a training to know the matters related to laboratory Medicine. Laboratory test results may influence up to 70 percent of medical decision making. However, one must wonder whether the test results are being interpreted correctly, and—if not—what the impact is of incorrect or inappropriate interpretation on the accuracy of diagnostic decision making based, in part, on laboratory test results. It is not just in India or developing countries but also in developed countries. The lack of confidence in interpreting laboratory test results may be directly related, as suggested by Dr. Lopasata, to the sparse training in laboratory medicine provided in most United States medical schools.
It is important for clinicians and laboratorians to recognize that laboratory data, although potentially extremely useful in diagnostic decision-making, should be used as an aid and adjunct to the constellation of findings (e.g., history, physical exam, etc.) relevant to the patient. Laboratory data is never a substitute for a good physical exam and patient history (clinicians should treat the patient, not the laboratory results). Above all treating the patients with wrong laboratory results can be dangerous to life, however well read physicians and competent surgeons dependent on least number of investigations. Many believe that Laboratories should be servants of the good physicians and not the masters to fish the matters.
(The Author is Microbiologist Certified infection control Auditor, Kidney Hospital Srinagar. Email: Jkakroo@gmail.com)