You will be shown an abstract from a biomedical research paper. Given this abstract, your task is to extract all unique entities of the following types: ["Chemical"].

Please return the output as a JSON object of the format: {"Chemical": ["Arsenic", ...]}. The keys should be entity types and values should be lists of extracted entities belonging to the corresponding type. If you cannot find entities belonging to a specific type, the value should be [].

Only output the JSON object and do not include any additional text.

Abstract:

Korean guidelines for pharmacoeconomic evaluation (second and updated version) : consensus and compromise. The first version of the Korean guidelines for pharmacoeconomic evaluation was published by Health Insurance Review and Assessment Service (HIRA) in 2006. Since the introduction of the first version, domestic experience with the application of the recommendations has accumulated, and methodologies in certain areas have progressed considerably. Based on these experiences, HIRA initiated a guidelines revision project to address the need for revisions. The purpose of this study is to share the process used to complete these guideline revisions and to provide the contents of the revised guidelines. In developing the current revision, meetings with the advisory committee and working-level meetings with pharmaceutical companies were held several times to reach as much of a consensus as possible, and the results of a survey of pharmaceutical companies and decision makers regarding the existing guidelines were considered. The second version of the guidelines clarified the level of data requirement ('must', 'recommended', 'preferred') based on the data availability, the information needs of the decision makers and the strength of the evidence. The recommended perspective economic studies should take has been modified and additional guidance has been provided on QALY measurement. Manuals for systematic reviews and indirect comparisons have been published, and a standardized reporting format for expert opinions has been added. Sections on preferred methods for evaluations, sensitivity analysis, modelling and time horizon have been elucidated. The revised guidelines clarify the expression of the recommendations, making them more user-friendly, and provide more specific guidance to improve the quality and comparability across submissions.
{"Chemical": []}