In a medical information system, with respect to a plurality of kinds of medical databases, a plurality of search items included in a search query inputted by a user are sorted in accordance with search divisions, and thereby divided into a finding report search query and a specimen test query. By using these queries, the corresponding databases are searched independently, and individual search results obtained therefrom are combined to generate a combined search result. The individual search result is assigned with an individual score in accordance with the matching degree with the search item. In combining the individual search results, a relevancy score is assigned. The search results are ranked and combined in descending order of the scores. This requires only one issuance of a search execution order without the need to perform a search operation a plurality of times, in order to obtain a desired search result.