ABSTRACT
This chapter addresses study design factors that influence clinical pathology test selection, timing, and frequency; sources of variability that confound data interpretation; general principles of data interpretation; and common patterns and correlative findings for standard hematology, coagulation, clinical chemistry, urinalysis, and urine chemistry tests. Nonclinical studies are usually designed and conducted in a tightly controlled manner in order to minimize variability of measured endpoints and more confidently determine effects of test article administration. The obvious effect on test selection and frequency, these multiple blood collections can and do significantly affect the results of many clinical pathology tests. Frequency and timing of clinical pathology testing are dependent on several factors. Blood collection from mice for clinical pathology tests is usually a terminal procedure and can only be done at the time of sacrifice. Clinical pathology testing is not recommended for rodent toxicity studies longer than 52 weeks because of naturally occurring disease conditions that cause excessive variability in results.
