In recent years, the increasing volume and complexity of data, especially in domains like healthcare, has emphasized the need for improved use of data to extract valuable insights, that can positively impact society in multiple perspectives (e.g., economic, societal, life quality). The importance of data integration has grown, since the combination of multiple datasets can drastically enhance the value of analysis, compared to individual dataset analysis. However, significant challenges remain, including compatibility issues among data sources and lack of standardization, restricting the full potential of such analyses. This manuscript explores the purpose and importance of data integration, focusing on the healthcare domain. A methodology is proposed, outlining the steps for harmonizing and integrating diverse datasets to ensure consistency and compatibility. This aims to enable advanced analysis, resulting in more accurate outcomes than those derived from using a single dataset alone.