Effects of non-analytical factors on the quality of laboratory results.

The quality of clinical laboratory measurement is comprised of 2 phases, the analytical and non-analytical phases. Nowadays, a well established quality control system has been applied. However, the non-analytical phase is a state of the art that must be paid attention to. We studied the non-analytical (pre- and post-) factors. A questionnaire was distributed to 298 hospital laboratories whom participated in the External Quality Assessment Scheme in Clinical Chemistry (EQAC) program of Faculty of Medical Technology, Mahidol University. The respondent rate was 71%. Most of the responder was female with a bachelor degree in medical technology or equivalent, who was the chief of the laboratory. Results shows that patient preparation, patient identification, specimen acquisition, specimen handling, and documentary system (specimen recording and result reporting) were important consideration factors. The turnaround time was also a main issue. Verification of test results was an important process too. Finally, as a good laboratory practice, one must has the strategies to detect and eliminate the non-analytical errors.