Network meta-analysis (NMA) is a statistical technique that integrates data from multiple clinical studies and compares the efficacy and safety of multiple interventions, which can provide pro and con ranking results for all intervention options in the evidence network and provide direct evidence support for clinical decision-making. At present, NMA is usually based on the aggregation of the same type of data set, and there are still methodological and software difficulties in achieving cross-study design and cross-data format data set merging. The crossnma package of R programming language is based on Bayesian framework and Markov chain Monte Carlo algorithm, extending the three-level hierarchical model to the standard NMA data model to achieve differential merging of varied data types. The crossnma package fully considers the impact of risk bias caused by the combination of different types of data on the results by introducing model variables. In addition, the package provides functions such as result output and easy graphing, which makes it possible to combine NMA across study designs and evidence across data formats. In this study, the model based on crossnma package method and software operation will be demonstrated and explained through the examples of four individual participant datasets and two aggregate datasets.
ObjectiveTo investigate the construction strategy of a knowledge base for health technology assessment (HTA) indicators based on a multi-granularity knowledge representation model, in order to meet the users' diverse demands for HTA knowledge services. MethodsFirstly, we constructed a multi-granularity HTA indicator knowledge representation model based on systematically analyzing the content and structure of the HTA indicator system in literature. Secondly, we extracted multi-granularity HTA indicator knowledge from literatures and conduct subject indexing in a human-computer collaborative way. Finally, based on the HTA knowledge service requirements, a prototype of the HTA indicator knowledge base-HTA Indicators was designed and developed. ResultsA multi-granularity HTA indicator knowledge representation model was constructed, covering 5 core knowledge units(indicator systems, indicator items, formulas, measurement variables, and subjects), 20 types of attributes, and 12 types of relationships. This model represents the intrinsic characteristics and connections between multi-granularity indicator knowledge units. Knowledge extraction and subject indexing of multi-grain HTA indicators were conducted based on 227 HTA indicator documents, forming instance data. Finally, a prototype of the HTA indicator knowledge base, named HTA Indicators, was developed.HTA Indicators provides services such as multi-granularity HTA indicator knowledge retrieval, navigation, and linking. ConclusionThe construction strategy of the HTA indicator knowledge base based on the multi-granularity knowledge representation model is feasible. The indicator knowledge base can achieve multi-dimensional semantic organization of indicator knowledge, provide multi-level and multi-dimensional indicator knowledge retrieval and discovery services, and meet the users' demand for precise HTA knowledge. In the future, we will explore the use of cutting-edge technologies such as large language models to achieve the automated construction of large-scale HTA knowledge, thereby enhancing the efficiency and intelligence level of knowledge base construction.