1. Overuse of INR and PT Testing in Medical Inpatients
Kevin Pham, PGY2

2. Guidelines
JAMA. 1989;262(17):2429.

3. Preoperative Testing
Liver function testing (including INR/PT) only if there are suspicions for liver disease based on prior abnormal LFTs, history, and exam.
Nature Clinical Practice Gastroenterology & Hepatology ;(4) :

4. Methods Cross sectional analysis Sample size n=20
Randomly review current medical inpatient charts until sample size is attained.
Only one INR/PT per patient closest to admission date was included in sample.
Inclusion criteria: medical inpatients, INR testing during current admission
Exclusion criteria: surgical, MICU, SICU, heme/onc, OB/GYN inpatients, and those without INR/PT testing.

5. Results Total charts review: 28 INR/PT testing present: 20
INR/PT testing absent: 8
Indicated: 10
Not Indicated: 10

6. Results 10/20 INR/PT tested (50%) were not indicated
1/10 INR/PT tested (10%) of the “not indicated” group was abnormal (based on UCI Medical Center laboratory reference ranges).
Abnormal INR/PT did not have clinical significant and did not change management.

7. Results
Indications for inappropriate INR/PT testing were unknown since they were not documented.
Inappropriate INR/PT ordered by ED: 4/10 (40%)
Inappropriate INR/PT ordered by medical residents: 6/10 (60%)

8. Results Indications of appropriate INR/PT testing
1/10 for Coumadin bridging for LV thrombus
3/10 for malnutrition and invasive procedure
3/10 for cirrhosis and invasive procedure
3/10 for active bleeding

9. Cost Cost per INR/PT testing: $8.45 Charge per test: $59.86
Patient volume 2013 (Tower): 3,343
Test volume 2013 for tower patients: 8,343
Assuming 50% of INR/PT testing are inappropriate as demonstrated by these data, potential cost annually due to inappropriate INR/PT is $35,249.
Inappropriate charge to patient is $249,705.

10. Conclusion
The incidence and cost of inappropriate INR/PT testing is high.
Increased awareness of guidelines for INR/PT testing may reduce the incidence and cost.

11. References
Erban, S.B., et al. Routine use of the Prothrombin and Partial Thromboplastin Times. JAMA. 1989;262(17) :2429.
Hanje, A.J and Patel, T. Preoperative evaluation of patients with liver disease. Nature Clinical Practice Gastroenterology & Hepatology ;(4) :