From Narcis.nl :" Patients with substance use disorder (SUD) are frequently suffering from co-occurring somatic disorders, increasing the risk of mortality. Somatic health care utilization (sHCU) often remains unknown to the physician during SUD treatment. This paper analyses sHCU and associated costs among patients in SUD treatment compared to matched, non-substance dependent controls. METHODS: Health care utilization data on 4972 SUD patients were matched to 19,846 controls by gender, birth year and ethnic origin. Subcategories of patients were formed based on SUD and on co-morbid psychiatric disorder. Data on sHCU during the year prior to the last treatment contact (the 'index date') for both patients and their matched controls were extracted from a health insurance database. RESULTS: Patients had a higher sHCU (with increased associated costs) than controls, especially when alcohol dependence was involved. In particular, sHCU for cardiovascular, respiratory, infectious diseases, injuries and accidents was increased among patients. However, the use of preventive medication, such as lipid-lowering drugs, is lower among SUD patients. Co-morbidity of psychiatric disorders led to further increase of sHCU, whereas patients with comorbid non-affective psychotic disorder (NAPD) showed lower sHCU and costs. CONCLUSION: Patients with SUD overall have a high sHCU, associated with high costs. There are indications that SUD patients have less access to preventive medication. Patients with comorbid NAPD are at risk of possible underutilization of somatic health care. Furthermore, we conclude that these larger administrative databases allow for comparisons between various diagnostic categories."