Abstract The clinical diagnostic laboratory plays a very important role in the safe delivery of quality service to the patient. Over 70 percent of all management decisions in clinics and hospitals are based on laboratory results. It is therefore of paramount importance that the laboratory issues out reports that are accurate, reliable, reproducible and available to clinicians in a clinically relevant time frame. The diagnostic cycle can be divided into three phases (which has been further divided into five), with the pre analytical phase being the most error prone. A number of variables effect the results and each variable has to be controlled if we wish to obtain reliable results. Sensitivity and specificity are inherent attributes of a test, but the positive and negative predictive value depends upon the prevalence of the disease in the community. We can increase the value of the test by considering the likelihood ratio and understanding the purpose of the test.
Abstract The clinical diagnostic laboratory plays a very important role in the safe delivery of quality service to the patient. Over 70 percent of all management decisions in clinics and hospitals are based on laboratory results. It is therefore of paramount importance that the laboratory issues out reports that are accurate, reliable, reproducible and available to clinicians in a clinically relevant time frame. The diagnostic cycle can be divided into three phases (which has been further divided into five), with the pre analytical phase being the most error prone. A number of variables effect the results and each variable has to be controlled if we wish to obtain reliable results. Sensitivity and specificity are inherent attributes of a test, but the positive and negative predictive value depends upon the prevalence of the disease in the community. We can increase the value of the test by considering the likelihood ratio and understanding the purpose of the test.