No risk of drug-associated liver injury with?1-adrenoreceptor blocking agents in men with BPH: results from an observational study using the GPRD

Secondary analysis of large databases for hepatology research

Secondary analysis of large datasets involves the utilization of existing data that has typically been collected for other purposes to advance scientific knowledge. This is an established methodology applied in health services research with the unique advantage of efficiently identifying relationships between predictor and outcome variables but which has been underutilized for hepatology research. Our review of 1431 abstracts published in the 2013 European Association for the Study of Liver (EASL) abstract book showed that less than 0.5% of published abstracts utilized secondary analysis of large database methodologies. This review paper describes existing large datasets that can be exploited for secondary analyses in liver disease research. It also suggests potential questions that could be addressed using these data warehouses and highlights the strengths and limitations of each dataset as described by authors that have previously used them. The overall goal is to bring these datasets to the attention of readers and ultimately encourage the consideration of secondary analysis of large database methodologies for the advancement of hepatology.

Assessment of case definitions for identifying acute liver injury in large observational databases

BACKGROUND

Determining the aetiology of acute liver injury (ALI) may be challenging to both clinicians and researchers. Observational research is particularly useful in studying rare medical outcomes such as ALI; however, case definitions for ALI in previous observational studies lack consistency and sensitivity. ALI is a clinically important condition with various aetiologies, including drug exposure.

OBJECTIVE

The aim of this study was to evaluate four distinct case definitions for ALI across a diverse set of large observational databases, providing a better understanding of ALI prevalence and natural history.

DATA SOURCES

Seven healthcare databases: GE Healthcare, MarketScan(®) Lab Database, Humana Inc., Partners HealthCare System, Regenstrief Institute, SDI Health (now IMS Health, Inc.), and the National Patient Care Database of the Veterans Health Administration.

METHODS

We evaluated prevalence of ALI through the application of four distinct case definitions across seven observational healthcare databases. We described how laboratory and clinical characteristics of identified case populations varied across definitions and examined the prevalence of other hepatobiliary disorders among identified ALI cases that may decrease suspicion of drug-induced liver injury (DILI) in particular.

RESULTS

This study demonstrated that increasing the restrictiveness of the case definition resulted in fewer cases, but greater prevalence of ALI clinical features. Considerable heterogeneity in the frequency of laboratory testing and results observed among cases meeting the most restrictive definition suggests that the clinical features, monitoring patterns and suspicion of ALI are highly variable among patients.

CONCLUSIONS

Creation of four distinct case definitions and application across a disparate set of observational databases resulted in significant variation in the prevalence of ALI. A greater understanding of the natural history of ALI through examination of electronic healthcare data can facilitate development of reliable and valid ALI case definitions that may enhance the ability to accurately identify associations between ALI and drug exposures. Considerable heterogeneity in laboratory values and frequency of laboratory testing among individuals meeting the criteria for ALI suggests that the evaluation of ALI is highly variable.

Association between tetracycline or doxycycline and hepatotoxicity: a population based case-control study

BACKGROUND AND OBJECTIVE

An FDA Working Group, along with representatives of PhRMA and the American Association for the Study of Liver Diseases, as well as the Institute of Medicine Report 'To Err is Human: Building a Safer Health Care System' have suggested that post-marketing drug surveillance is a important method to decrease adverse drug events. While tetracyclines are known to cause hepatotoxicity, no post-marketing drug surveillance studies have examined the risk of developing hepatotoxicity with tetracyclines. Therefore, the objective of this study is to determine the difference in risk of hepatotoxicity in patients receiving doxycycline or tetracycline using California Medicaid claims.

METHODS

This study used a retrospective, matched case-control study using California Medicaid claims data. The cases were defined as recipients who had at least one diagnosis of hepatotoxicity any time from 1 July 1999 to 31 December 2001. One control was identified for each case, matched on age, gender and race. Logistic regression was used to determine the adjusted odds ratio (OR) and 95% confidence intervals for current users and past users of tetracycline and doxycycline. Covariates controlled for in the analysis were age, use of other hepatotoxic drugs, renal dysfunction, pregnancy, and alcohol or illicit drug use.

RESULTS

A total of 3377 cases of hepatotoxicity were identified. Current users and past users of tetracycline had a statistically significant increased risk of developing hepatotoxicity (current use OR 3.70, 95% CI 1.19-11.45; past use OR 2.72, 95% CI 1.26-5.85). Current users or past users of doxycycline did not have an increased risk of developing hepatotoxicity (current use OR 1.49, 95% CI 0.61-3.62; past use OR 1.74, 95% CI 0.99-3.06). Tetracycline was commonly used for acne, acute bronchitis and upper respiratory infections. Doxycycline was commonly used for acute bronchitis, vaginitis and acne.

DISCUSSION AND CONCLUSION

Doxycycline was potentially less hepatotoxic than tetracycline. Doxycycline could potentially be a safe substitute for tetracycline, when appropriate.