(18)In order to ensure adaptation to changes to the UN COICOP, to amend the list of items regulated by implementing acts by adding items in order to take account of technical developments in the statistical methods and based on the evaluation of pilot studies, and to modify the list of sub-indices of ECOICOP that Member States are not required to produce in order to include games of chance in the HICP and the HICP-CT, the power to adopt acts in accordance with Article 290 TFEU should be delegated to the Commission. It is of particular importance that the Commission carry out appropriate consultations during its preparatory work, including at expert level. The Commission, when preparing and drawing up delegated acts, should ensure a simultaneous, timely and appropriate transmission of relevant documents to the European Parliament and to the Council.