Factors affecting hospital length of stay: is substance use disorder one of them? A study in a Greek public psychiatric hospital.

Comorbidity of psychiatric disorder and substance use disorder (SUD) is very common. Clinical experience says that comorbidity increases inpatient length of stay. We aimed to discover which factors affect length of stay for inpatients at a psychiatric department in a specialized mental hospital in a Greek urban area, and specifically whether SUD is one of them. All patients admitted over a 12-month period were given the CAGE questionnaire and that part of the EUROPASI questionnaire dealing with substance use. This was followed by a diagnostic interview to establish the final diagnosis in accordance with the DSM-IV criteria. Following this, the patients' characteristics in conjunction with their average length of stay were all evaluated statistically. A total of 313 patients were assessed. Present substance use disorder was identified in 102 individuals (32.6%). The principal substances involved in addiction or abuse were alcohol, cannabis, benzodiazepines, and opiates. Patients differed as to their cooperation with the medication regime. On the other hand, there was no statistical difference regarding the number of hospitalisations. Psychopathology was not found to play a direct role, as no one diagnosis correlated with length of stay. The factors found to affect length of stay in this psychiatric department were the length of time they had been mentally ill and cooperation in taking medication. It appears that SUD is not one of the factors affecting length of stay.