Intensive Home Treatment compared to Inpatient Psychiatric Treatment: A 36-Month Follow-Up of a Propensity-Score Matched Retrospective Multicenter Cohort Study

Background: Intensive Home Treatment (IHT) has emerged as an effective alternative to inpatient care for acute psychiatric crises, reducing hospital admissions in the short term. However, long-term outcomes beyond 12 months remain understudied, particularly regarding readmissions, cumulative treatment days, and broader psychiatric service utilization. This study evaluates the 36-month effectiveness of IHT compared to inpatient treatment (IT) in routine care, focusing on readmission rates, treatment days, and outpatient service engagement Methods A retrospective matched cohort study was conducted using electronic health records from three psychiatric hospitals in Berlin, Germany. Patients receiving IHT were propensity-score matched (1:1) to IT patients based on age, gender, diagnosis, and prior service use. Outcomes included inpatient/combined readmissions, treatment days, time to readmission, and first-time us of the Psychiatric Outpatient Department (POD) over 36 months. Statistical analyses employed logistic regression, survival analysis (Cox model), and non-parametric tests. Results 263 patients receiving IHT were propensity-score matched to 263 patients treated with IT with no statistical differences at baseline. The IHT group had significantly lower inpatient readmission rates (41.1% vs. 55.5%, p = 0.001), fewer inpatient readmissions (mean 1.72 vs. 2.02, p = 0.005), and fewer inpatient days (48.5 vs. 51.7, p = 0.003) compared to IT. Time to readmission was longer for IHT (median not reached vs. 610 days for IT, p = 0.001). Combined readmission rates (IHT + IT + day clinic) did not differ significantly (61.2% vs. 64.3%, p = 0.47). IHT patients were more likely to initiate for the first time a POD treatment (33.5% vs. 24.7%, p = 0.035) and had more IHT readmissions (mean 0.85 vs. 0.35, p < 0.001). Conclusions IHT demonstrates sustained long-term benefits, reducing inpatient readmissions and prolonging readmission-free periods over 36 months. While overall psychiatric service utilization was similar between groups, IHT facilitated greater engagement with outpatient rather than inpatient care. Findings support IHT as a viable, sustainable alternative to IT, particularly in urban settings, with potential to rebalance care toward community-based services. Limitations include restricted generalizability to rural areas and lack of clinical symptom data. Further multi-centre studies are needed to confirm these results regarding long-term effects across diverse healthcare systems. Trial registration: German Clinical Trials Register (DRKS), DRKS00036833. Registered Mai 21st 2025, https://www.drks.de/search/de/trial/DRKS00036833/details