Original articles

Potential for medical error: Incorrectly completed request forms for thyroid function tests limit pathologists’ advice to clinicians

Annalise Edith Zemlin, Louise Nutt, Lesley Jean Burgess, Fredeline Eiman, Rajiv Timothy Erasmus


Objectives: Recent publications have emphasized the importance of laboratory errors in the pre- and post-analytical phases and their impact on results. In view of the paucity of articles describing these errors, especially in a primary health care setting, we audited laboratory request forms received from primary care clinics at our laboratory requesting thyroid function tests (TFT). Thyroid stimulating hormone (TSH) is a first-line thyroid function test, and if abnormal, reflex thyroxine (T4) or tri-iodothyronine (T3) testing is requested depending on clinical and medication data provided. Interpretative comments are added to all TFT results.
Design: We assessed 482 laboratory request forms for TFT from primary health care clinics for specific parameters. We separately assessed those forms containing medication details for thyroxine replacement therapy to see whether this was registered correctly by reception staff.
Results: A total of 482 forms were analysed. Medication(s) used by the patient (74.5%) and doctor’s contact number (65.1%) were the most incomplete parameters. Of the 123 patients with medication details, 62 (50.4%) were on thyroxine. Twenty-four (38.7%) of these were not captured by the reception staff and had to be added by the pathologist.
Conclusions: There are few studies examining the frequency and impact of incomplete laboratory forms on laboratory errors. There are even fewer studies examining interpretative comments accompanying clinical biochemistry results. We used this study to hypothesize how pre-analytical errors in the completion of request forms may lead to incorrect interpretative comments and inappropriate reflex testing, and thus influence quality of the post-analytical phase.

Authors' affiliations

Annalise Edith Zemlin,

Louise Nutt,

Lesley Jean Burgess,

Fredeline Eiman,

Rajiv Timothy Erasmus,

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laboratory errors, laboratory request forms, interpretative comments, reflex testing, thyroid function tests

Cite this article

South African Medical Journal 2009;99(9):668.

Article History

Date submitted: 2008-10-31
Date published: 2009-09-02

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