Analysis of medical prescribing practices for hepatitis B serology tests

Self-reported patient history to assess hepatitis B virus serological status during a large screening campaign

When assessing hepatitis B virus (HBV) status in clinical settings, it is unclear whether self-reports on vaccination history and previous HBV-test results have any diagnostic capacity. Of 3997 participants in a multi-centre HBV-screening study in Paris, France, 1090 were asked questions on their last HBV-test result and vaccination history. Discordance between self-reported history compared with infection status (determined by serology) was calculated for participants claiming ‘negative’, ‘effective vaccine’, ‘past infection’, or ‘chronic infection’ HBV-status. Serological testing revealed that 320 (29.4%) were non-immunised, 576 (52.8%) were vaccinated, 173 (15.9%) had resolved the infection and 21 (1.9%) were hepatitis B surface antigen positive. In total 208/426 (48.8%) participants with a self-reported history of ‘negative’ infection had a discordant serological result, in whom 128 (61.5%) were vaccinated and 74 (35.6%) had resolved infections. A total of 153/599 (25.5%) participants self-reporting ‘effective vaccine’ had a discordant serological result, in whom 100 (65.4%) were non-immunised and 50 (32.7%) were resolved infections. Discordance for declaring ‘past’ or ‘chronic infection’ occurred in 9/55 (16.4%) and 3/10 (30.0%) individuals, respectively. In conclusion, self-reported HBV-status based on participant history is partially inadequate for determining serological HBV-status, especially between negative/vaccinated individuals. More adapted patient education about HBV-status might be helpful for certain key populations.

Interventions to Educate Family Physicians to Change Test Ordering: Systematic Review of Randomized Controlled Trials

The purpose is to systematically review randomised controlled trials (RCTs) to change family physicians’ laboratory test-ordering. We searched 15 electronic databases (no language/date limitations). We identified 29 RCTs (4,111 physicians, 175,563 patients). Six studies specifically focused on reducing unnecessary tests, 23 on increasing screening tests. Using Cochrane methodology 48.5% of studies were low risk-of-bias for randomisation, 7% concealment of randomisation, 17% blinding of participants/personnel, 21% blinding outcome assessors, 27.5% attrition, 93% selective reporting. Only six studies were low risk for both randomisation and attrition. Twelve studies performed a power computation, three an intention-to-treat analysis and 13 statistically controlled clustering. Unweighted averages were computed to compare intervention/control groups for tests assessed by >5 studies. The results were that fourteen studies assessed lipids (average 10% more tests than control), 14 diabetes (average 8% > control), 5 cervical smears, 2 INR, one each thyroid, fecal occult-blood, cotinine, throat-swabs, testing after prescribing, and urine-cultures. Six studies aimed to decrease test groups (average decrease 18%), and two to increase test groups. Intervention strategies: one study used education (no change): two feedback (one 5% increase, one 27% desired decrease); eight education + feedback (average increase in desired direction >control 4.9%), ten system change (average increase 14.9%), one system change + feedback (increases 5-44%), three education + system change (average increase 6%), three education + system change + feedback (average 7.7% increase), one delayed testing. The conclusions are that only six RCTs were assessed at low risk of bias from both randomisation and attrition. Nevertheless, despite methodological shortcomings studies that found large changes (e.g. >20%) probably obtained real change.

Discrepant hepatitis B surface antigen results in pregnant women screened to identify hepatitis B virus infection

OBJECTIVE

To resolve discrepant hepatitis B surface antigen (HBsAg) results for pregnant women screened for hepatitis B virus (HBV) infection.

STUDY DESIGN

A case was defined as discrepant HBsAg (reactive followed by non-reactive) result during the same pregnancy. The Centers for Disease Control and Prevention examined a convenience sample of cases passively reported by US Perinatal Hepatitis B Prevention Programs. Using a standard form, available results were obtained for hepatitis B tests and vaccination histories. Results were independently reviewed by 3 viral hepatitis experts and a clinical virologist to resolve discrepancies. The initial HBsAg result was classified as probable true positive, probable false positive, or unresolved.

RESULTS

From April 2009-December 2011, 142 (75.9%) of 187 reported discrepant cases met the case definition. Of the 142 initial reactive HBsAg results, 113 (79.5%) were laboratory-confirmed, and 89 (62.7%) were resolved. Among these 89 cases, the initial test was a probable true positive in 14 (15.7%), and a false positive in 75 (84.3%). Total antibody to hepatitis B core antigen was positive for 11 (78.6%) of the true positive cases and negative for 67 (89.3%) of the false positive cases. True positives included 2 cases of resolving acute HBV infection and one case recently given hepatitis B vaccination.

CONCLUSIONS

In this retrospective analysis of discrepant HBsAg-reactive screening results from pregnant women, the majority were false positives, but true positives occurred. Testing for total hepatitis B core antibody, an indicator of past or current HBV infection, was useful for resolving discrepancies.