Referral to aftercare following inpatient withdrawal treatment and readmission: retrospective chart review of patients with substance use disorders.

Aftercare following inpatient withdrawal treatment improves the prognosis and prevents future readmissions in patients with substance use disorders. According to the stepped care approach, the setting and intensity of aftercare should be adjusted to the patients' specific needs and resources. This study evaluated the real-life referral to different types of aftercare in Switzerland and the rate of inpatient readmission within a 1-year follow-up. All substance use disorder patients admitted for inpatient withdrawal treatment in a Swiss psychiatric hospital between January and December 2016 (n = 497) were included in this retrospective study. Clinical and sociodemographic characteristics were extracted from the electronic medical records and their impact on the likelihood of being referred to a particular type of aftercare (general practitioner, psychiatric outpatient care, psychiatric day clinic, inpatient rehabilitation programme) was evaluated. For each type of referral, we determined the readmission rate within one year after discharge. In the sample of substance use disorder patients (mean age 41 years; 69% male), alcohol use disorder was by far the most frequent substance use disorder. Most patients were referred to psychiatric outpatient care (39.8%), followed by a general practitioner (31.0%), inpatient rehabilitation (19.3%) and psychiatric day clinic (9.9%). Patient characteristics that point to an unfavourable course of disease, including higher symptom severity, history of more than two previous admissions, compulsory admission and treatment discontinuation, were associated with a higher likelihood to be referred to lower-level aftercare (general practitioner, psychiatric outpatient care), whereas patients with lower symptom severity, fewer than two previous admissions, voluntary admission and regular discharge were more likely to be referred to high-intensity aftercare (psychiatric day clinic, inpatient rehabilitation). The readmission rate after one year did not differ between the different settings of aftercare (range 40.4-42.9%). The findings of this study suggest that patients suffering from severe substance use disorders and/or from an unfavourable course of disease who would benefit from a more intensive aftercare setting, such as psychiatric day clinics or inpatient rehabilitation programs, might be under-treated, whereas patients with a rather favourable prognosis might similarly benefit from a less intensive treatment setting, such as psychiatric outpatient care. Regarding the comparable readmission rates, we recommend considering more efficient resource management by promoting stepped care approaches for substance use disorders and establishing standardised placement criteria in Switzerland.