Application of biclustering algorithm in adverse drug reaction monitoring system of China.

PURPOSE: Signal evaluation is considered to be a tedious process owing to the large number of disproportional signals detected. This study aimed to apply a biclustering algorithm in the spontaneous reporting system of China and to obtain the optimal parameters. The biclustering algorithm is expected to improve the efficiency of signal evaluation by identifying similar signal groups. METHODS: Information component (IC) was the method used for disproportionality analysis. By using IC thresholds of various strengths (0.05-4.00), the original quantitative data matrix was transformed into 80 different binary data matrices, where each cell contained either a 1 or 0. The biclustering results were obtained using a total of 720 Bimax algorithm parameters (minimal number of columns and rows was 3, 4, or 5). Next, the optimal parameters were determined through the comprehensive evaluation of the rank sum ration. Finally, we examined the biclustering results under the optimal parameters and evaluated the effect of biclustering analysis on adverse drug reaction (ADR) data in China. RESULTS: The optimal strength of the IC threshold was 0.80, and the minimum number of rows and columns was 3. After taxonomic evaluation, we also found that 1836 biclusters (42.8%) contained similar drugs or similar ADRs, which accounted for 72.3% of signals unevaluated. CONCLUSIONS: Applying biclustering analysis in spontaneous reporting system could provide support in confirming unrecognized ADRs, identifying rare ADRs, and screening drug-ADR pairs, which need more attention. Biclustering algorithm could improve the efficiency of signal detection and evaluation in China.

Signal Detection Based on Time to Onset Algorithm in Spontaneous Reporting System of China.

INTRODUCTION: The method of time-to-onset (TTO) has been proposed to overcome the drawbacks of traditional disproportionality analyses (DPAs), and it has been used for detecting safety signals of vaccines and some non-vaccine products in spontaneous reporting systems (SRSs). However, there is no consensus on its superiority over DPAs. Further, it is still not clear whether this novel approach can be generalized to the entire national SRS database. OBJECTIVE: The purpose of this study was to generalize the TTO method to the Chinese SRS and to identify suitable parameters for its optimal performance. METHODS: Reports submitted to the national SRS of China in 2014 were used as the data source for analysis. We evaluated the performance of TTO by using product labels as proxies for the gold standard. A series of values of significance level and time windows were explored to identify the most suitable parameters for TTO based on Youden's index, a statistic that summarizes the performance of a diagnostic test. Additionally, we compared TTO with traditional DPAs and explored the characteristics of signals detected by these methods. RESULTS: Compared with DPAs, TTO had a lower sensitivity, but higher specificity and positive predictive value. At a significance level of 0.2 and no restrictions on time windows, TTO had the highest Youden's index. The kappa coefficients between TTO and DPAs were rather low, indicating poor agreement between the two methods. More than 30% of the true signals detected by TTO were not identified by DPAs. Furthermore, TTO needed more number of reports to be able to detect signals. CONCLUSIONS: TTO can detect signals missed by traditional DPAs and could be an important complementary tool to the currently used DPAs in the SRS of China. We recommend a significance level of 0.2 and no restrictions on time windows for TTO.

National ADR Monitoring System in China.

It has been more than 25 years since an adverse drug reaction (ADR) monitoring agency was first established in China. In the past few years, the National ADR Monitoring System (NADRMS) has developed rapidly in the country. However, this system has not been reviewed in detail in the literature. Our aim was to demonstrate how individual case safety reports (ICSRs) are reported and evaluated and how data quality control is achieved in China. We also aimed to discuss the present status and future of NADRMS. We reviewed the relevant regulations and literature around ADR reporting in China. ADR report collection tools in China have gone through three phases, namely paper-based reporting, software-based reporting using standalone computers, and online reporting. Nowadays the online reporting system plays an important role in China and the number of ADR reports has rapidly increased. NADRMS is similar to most of the ADR reporting systems around the world, but also has its own unique characteristics such as four levels of monitoring agencies. In summary, there is still a long way to go for China to establish a high-level ADR monitoring system to ensure drug safety.

Exploration of statistical shrinkage parameters of disproportionality methods in spontaneous reporting system of China.

PURPOSE: Statistical shrinkage is a potential statistical method to improve the accuracy of signal detection results and avoid spurious associations detected by disproportionality analyses. In this study, we introduced statistical shrinkage influence on disproportionality methods in spontaneous reporting system in China. METHODS: We added the shrinkage parameters in the numerator and denominator, denoted as in the formula of disproportionality analysis. The shrinkage parameters were subjectively set to between 0 and 5, with an interval of 0.1. Adverse drug reaction product label database was deemed as a proxy of golden standard to evaluate the effect of statistical shrinkage. Reports in the years of 2010-2011 were extracted from the national spontaneous reporting system database as the data source for analysis in this study. RESULTS: When α was around 0.5, the Youden index reached the maximum for each disproportionality methods in this study. The value of 0.6 was suggested as the most appropriate statistical shrinkage parameter for reporting odds ratio and proportional reporting ratio and 0.2 for information component based on the spontaneous reporting system of China.

A comparison of disproportionality analysis methods in national adverse drug reaction databases of China.

OBJECTIVE: Several disproportionality analysis methods are widely used for signal detection. The goal of this study was to compare the concordance of the performance characteristics of these methods in spontaneous reporting system of China. METHODS: Algorithms including reporting odds ratio (ROR), proportional reporting ratio (PRR) and information component (IC), a composite criterion previously used by Medicines and Healthcare Products Regulatory Agency (MHRA) were compared. Kappa coefficient was used as the gauge to test the concordance. Reports received in the year 2004 and 2005 were extracted for analysis in this study. RESULTS: After data processing, 361,872 reports representing 52,769 combinations were analysed. The analysis generated 24,022, 22,646, 5637 and 5302 signals of disproportionality by PRR, ROR, MHRA and IC, respectively. The kappa coefficient increased with the threshold of number of drug-adverse drug reactions (ADR) combination, and the coefficient exceeded 0.7 when the number of suspected drug-ADR exceeded 2. CONCLUSION: This study shows that different measures used are broadly comparable in spontaneous reporting system in China when two or more cases per combination have been collected.