Numbers and Rates of Inappropriate Acute Viral Hepatitis Serology Testing Before and After Interventions
| Test | |||
|---|---|---|---|
| Data Collection Period | Variable | Anti-HAV IgM Test | Anti-HBc IgM |
| Preintervention | Total eligible tests analyzed, n | 2,439 | 4,462 |
| ALT or AST ≥250 U/L, n (%) | 228 (9.3) | 280 (6.3) | |
| ALT or AST <250 U/L, n (%) | 2,211 (90.7) | 4,182 (93.7) | |
| Rate of inappropriate testing, % | 90.7 | 93.7 | |
| Post first intervention | Total tests ordered, n | 1,495 | 1,830 |
| Total eligible tests analyzed, n | 1,311 | 1,573 | |
| ALT or AST ≥250 U/L, n (%) | 255 (19.5) | 266 (16.9) | |
| ALT or AST <250 U/L, n (%) or serologic evidence of immunity | 1,056 (80.5) | 1,307 (83.1) | |
| Rate of inappropriate testing, % | 80.5 | 83.1 | |
| P value | <0.0001 | <0.0001 | |
| Post second intervention | Total tests ordered, n | 1,159 | 1,437 |
| Total eligible tests analyzed, n | 998 | 1,184 | |
| ALT or AST ≥250 U/L, n (%) | 199 (19.9) | 200 (16.9) | |
| ALT or AST <250 U/L, n (%) or serologic evidence of immunity | 799 (80.1) | 984 (83.1) | |
| Rate of inappropriate testing, % | 80.1 | 83.1 | |
| P value | <0.0001 | <0.0001 | |
Notes: Serologic evidence of immunity to HAV and HBV is defined as the presence a positive anti-HAV total (>6 months) and positive anti-HBs (>6 months), respectively. Eligible tests are less than the total tests, as tests without AST or ALT values within 30 days of ordering the serology were excluded. P value is 2-sided comparing the preintervention and postintervention appropriate and inappropriate proportions using Fisher exact test.
ALT, alanine aminotransferase; anti-HAV IgM, hepatitis A virus immunoglobulin M antibody; anti-HAV total, hepatitis A virus total antibody; anti-HBc IgM, hepatitis B virus core immunoglobulin M antibody; anti-HBs, hepatitis B virus surface antibody; HAV, hepatitis A virus; HBV, hepatitis B virus; AST, aspartate aminotransferase.