Associations of Race with Follow-up Patterns After Initial Abnormal Liver Tests in Primary Care

The Association of Abnormal Liver Tests with Hepatitis C Testing in Primary Care

BACKGROUND

As hepatitis C virus birth cohort (1945-1965) screening in primary care improves, testing patterns in response to persistently abnormal liver tests are less well known.

METHODS

This retrospective cohort study of a patient-centered medical home between 2007 and 2016 evaluates the association of abnormal liver chemistries and other clinical and demographic factors with hepatitis C antibody (HCV Ab) testing in patients with persistently abnormal liver tests. Patients with at least 2 consecutive abnormal liver tests were categorized by the clinical pattern of liver chemistry abnormality, including cholestatic, hepatocellular, and mixed patterns. The primary outcomes were: 1) completed HCV Ab tests; and 2) positive HCV Ab results for those patients tested.

RESULTS

Of 4512 patients with consecutive abnormal liver tests, only 730 (16%) underwent HCV Ab testing within 1 year of the second abnormality; 81/730 (11%) had HCV Ab detected. A logistic regression model revealed that mixed (odds ratio [OR] 2.20; 95% confidence interval [CI], 1.72-2.82) and hepatocellular (OR 1.43; 95% CI, 1.15-1.79) patterns of liver test abnormality, female sex, and alcohol and tobacco abuse were associated with higher odds of HCV Ab testing. Hepatocellular (OR 7.51; 95% CI, 2.18-25.94) and mixed patterns (OR 5.88; 95% CI, 1.64-21.15) of liver test abnormalities, male sex, Medicaid enrollment, and drug and tobacco abuse had higher odds of positive HCV Ab results.

CONCLUSIONS

There is opportunity to improve hepatitis C diagnostic testing in patients with consecutively elevated liver tests, and hepatocellular and mixed patterns of abnormality should prompt primary care providers to action.

When Do Clinicians Follow-up Abnormal Liver Tests in Primary Care?

BACKGROUND

Many guidelines addressing the approach to abnormal liver chemistries, including bilirubin, transaminases and alkaline phosphatase, recommend repeating the tests. However, when clinicians repeat testing is unknown.

MATERIAL AND METHODS

This retrospective study followed adult patients with abnormal liver chemistries in a patient-centered medical home (PCMH) from 2007 to 2016. All PCMH patients possessing at least 1 abnormal liver test (total bilirubin, aminotransferases and alkaline phosphatase) were included. Patients were followed from the index abnormal liver chemistry until the next liver test result, or the end of the study period. The primary predictor variable of interest was the number of abnormal chemistries (out of 4) on index testing. Demographic and clinical variables served as other potential predictors of outcome. A Cox proportional hazards model was applied to investigate associations between the predictor variables and the time to repeat liver chemistry testing.

RESULTS

Of 9,545 patients with at least 2 PCMH visits and 1 liver test abnormality, 6,489 (68%) obtained repeat testing within 1 year, and 80% of patients had follow-up tests within 2 years. Patients with multiple abnormal liver tests and those with higher degrees of abnormality were associated with shorter time to repeat testing.

CONCLUSIONS

A large proportion of patients with abnormal liver tests still lack repeat testing at 1 year. The number of liver abnormal liver tests and degree of elevation were inversely associated with the time to repeat testing.