[Laboratory diagnosis and practical treatment of patients]

The practical treatment of patients requires a reliable diagnosis and prognosis followed by therapy. Laboratory medicine is an essential scientific basis to rational treatment in each of these three phases. The significance, usefulness and extent of laboratory tests are largely dependent upon the disease spectrum. The possibilities and aims of laboratory medicine are: 1. Knowledge of and research into both the pathobiochemical and statistical connections between biochemical data and diseases leading to the selection of diagnostically reliable and relevant parameters. 2. Knowledge of the sensitivity, specificity and predictive values of relevant biochemical parameters and their application to the different clinical problems. 3. Evaluation of reliable analytical methods with details of their accuracy and precision. 4. Critical evaluation of pre-analytical factors. The translation of accurate laboratory data into clinically relevant information must always be coupled with a critical assessment of its diagnostic value, validity and range of error. An uncritical "consumption" of laboratory data is dangerous for both the patient and the clinician as is the suppression of these data when it does not fit the supposed diagnosis. Laboratory medicine is indispensible in proper patient care since it guarantees adequate medical action. The information that it delivers is binding and therefore offers help as well as protection.