Introduction: in the course of the research, the investigators will develop a decision-support system (comorbidity-DSS) consisting (1) a knowledge base (KB) consisting of (a) computer-interpretable clinical guidelines for type 2 diabetes and 2 other diseases from: obstructive pulmonary disease, osteoporosis, hypertension, and osteoarthritis; and (b) an ontology of relevant general medical knowledge that could complement (a) in order to propose non conflicting treatment options not mentioned in the clinical practice guidelines; and (2) an algorithm that matches the KB with a patient's data set to identify the guidelines-based recommendations applicable for the patient and their interactions and which proposes ways to mitigate conflicting interactions (e.g., suggesting to select intervention A.2 (instead of A.1) from guideline A and intervention B.3 (instead of B.1) from guideline B together with an action B' mentioned in the general medical knowledge, because these interventions are not conflicting yet A.3 fulfills the same goals as intervention A.1 and intervention B.3 + B' together fulfill the same goal as B.1).