Haematology Watch





Background: Accuracy and precision of tests in a laboratory are governed by strict quality control. Wrong test results can be due to pre-analytical, analytical, and post-analytical errors.

Objective: To detect frequency of pre-analytical errors in samples sent for coagulation tests.

Design: Retrospective observational study.

Place and duration of study: Fauji Foundation Hospital Rawalpindi, from Sep, 2008 to Dec, 2009.

Materials and Methods: All test samples sent to the Pathology Laboratory for coagulation tests were included. Data of each sample was scrutinized for comments of Over filled, Under filled, Clotted, Haemolysed, Wrong sample (i.e. improperly labeled sample), and Wrong tube (i.e. samples sent in tubes containing anticoagulant other than trisodium citrate) was analyzed by using descriptive statistics.

Results: Out of 1006 patients, 43 (4.27%) were under filled, 18 (1.8%) were clotted, 12 (1.2%) were over filled, 10 (1%) were haemolysed, and 1 (0.1%) was improperly labelled.

Conclusion: Underfilling and clotted samples were the most common pre-analytical errors in samples sent for coagulation tests.