Table 2.

Possible reasons for false positive or false negative ICD-9-CM coding for CMV on medical chart review

Patient	Reason for Admission	Possible Reason for CMV False Positive Coding
1	Disseminated histoplasmosis	CMV PCR reported at 403,850 copies/mL that was in error; revised 20 days after hospital discharge to < 200 copies/mL
2	Acute cellular rejection	Valganciclovir prophylaxis prescribed with no evidence of active CMV infection or disease
3	Abdominal pain
4	Transplant pyelonephritis	CMV PCR test was checked and negative
5	Weakness, anemia	CMV mentioned in history and physical as part of donor-recipient description, no CMV testing was performed
6	Elective bariatric surgery
7	Herpes zoster
8	Acute cellular rejection

Patient	Reason for Admission	Possible Reason for CMV False Negative Coding
1	Tissue-invasive gastrointestinal CMV disease	No identifiable reason; documented in chart; length of stay 7 days; CMV test result returned 6 days prior to discharge
2	Acute renal failure	No documentation in chart; length of stay 1 day; CMV test result returned on the day of discharge
3	Urinary tract infection	No documentation in chart; length of stay 5 days; CMV test result returned 3 days prior to discharge
4	Upper respiratory tract infection	No documentation in chart; length of stay 2 days; CMV test result returned on the day of discharge
5	Metastatic primary lung cancer	No documentation in chart; length of stay 25 days (until expiration); CMV test result returned 15 days prior to expiration
6	Acute renal failure	No documentation in chart; length of stay 5 days; CMV test result returned 4 days prior to discharge