Laboratory tests in older adults: Indications, interpretation, issues

Multiple and repetitive laboratory testing plays a major role in healthcare today. Testing has several values, including screening for disease, evaluating the stage of disease, and determining management strategies and their efficacy. Test results may be negative or positive, but can also be false positive and false negative, adding to difficulties in interpretation. The asymptomatic patient with abnormal test results is an enigma. Age by itself is not associated with much alteration in results. Marked variations in test results usually indicate the presence of underlying disease. Testing prior to a surgical procedure must be tailored to history, physical examination, and to the procedure itself. Results may be influenced by several factors, including gender, race, and the use of medications.