A study of pre-analytical variables in clinical biochemistry laboratory

Pre-analytical error decisively influences the total error and consequently the diagnostic accuracy. The following were the objectives for the study: 1. To detect the percent of pre-analytical errors in clinical biochemistry laboratory. 2. To categorize these pre-analytical errors. 3. To formulate corrective measures to be taken to avoid such errors.

Study period was for 3 months with documenting the frequency and type of pre-analytical errors occurring in the venous samples.

Average pre-analytical errors were 44.7% per day. Improper request, incorrect timing of sample, wrong tube collection and in-vitro hemolysis of samples amounted to the major proportion of errors.

Pre-analytical errors occurring in each laboratory have to be checked. Such errors are not inevitable and can be avoided with a diligent application of quality control, continuing education and effective collection systems to ensure total quality patient care.