Deficiencies of protein C, protein S, and antithrombin are the main inherited risk factors in Thai patients with venous thromboembolism, although the prevalence is not high.Methods:
To evaluate the appropriate use of the testing for these proteins, the test orders of 503 patients were retrospectively reviewed using the proposed guidelines. Inter-rater reliability between two investigators was also calculated.Results:
Of 503, 459 (91%; 95% confidence interval 88–93%) of the test orders were inappropriate. The most common cause of inappropriateness was testing during acute thrombosis (42.5%). Results were inconclusive in 105 (20.9%) patients who had isolated decrease in one of the proteins, mostly owing to lack of confirmation of the abnormal results. Kappa index for the reliability of two investigators was 0.79.Conclusion:
To enhance the appropriate use of hereditary thrombophilia screening tests, physician education concerning the patient selection, suitable timing for testing and repetition of the tests with abnormal results should be emphasized.