Background <p>Intensive Home Treatment (IHT) has been implemented as an alternative to inpatient psychiatric treatment for selected patients requiring acute care. While short-term reductions in inpatient utilization have been reported, evidence on long-term outcomes beyond 12 months—particularly regarding readmissions, treatment days, and broader psychiatric service use—remains limited. 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.</p> Methods <p>We conducted a retrospective propensity-score matched cohort study using routine clinical data from three psychiatric hospitals in Berlin, Germany. Patients receiving IHT were matched (1:1) to patients receiving IT based on age, gender, diagnosis, and prior service utilization. Outcomes included inpatient and combined readmissions (IT, IHT and day clinic), treatment days, time to readmission, and first-time use of the Psychiatric Outpatient Department (POD) over 36 months. Statistical analyses included binary logistic regression, Kaplan–Meier survival analysis with log-rank testing, and non-parametric tests.</p> Results <p>263 patients receiving IHT were matched to 263 patients treated with IT, with no statistical differences at baseline between groups. The IHT group had significantly lower inpatient readmission rates (41.1% vs. 55.5%, <i>p</i> = 0.001), fewer inpatient readmissions (mean 1.72 vs. 2.02, <i>p</i> = 0.005), and fewer inpatient days (48.5 vs. 51.7, <i>p</i> = 0.003) compared to IT over 36 months. Time to readmission was longer for IHT (median not reached vs. 610 days for IT, <i>p</i> = 0.001). Combined readmission rates (IHT + IT+day clinic) did not differ significantly (61.2% vs. 64.3%, <i>p</i> = 0.47). IHT patients were more likely to initiate for the first time a POD treatment (33.5% vs. 24.7%, <i>p</i> = 0.035) and had more IHT readmissions (mean 0.85 vs. 0.35, <i>p</i> &lt; 0.001).</p> Conclusions <p>In this selected cohort of patients deemed suitable for home-based acute care, IHT was associated with fewer inpatient readmissions and a longer time to inpatient readmission over a 36-month follow-up period. Overall acute psychiatric care use (inpatient + IHT) did not differ between groups, suggesting that IHT may not reduce overall acute care need but may shift care from inpatient settings toward home-based treatment.These findings should be interpreted cautiously given the non-randomized study design and the likelihood of residual selection bias. 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.</p> Trial registration <p>German Clinical Trials Register (DRKS), DRKS00036833. Registered May 21, 2025, <a href="https://www.drks.de/search/de/trial/DRKS00036833/details">https://www.drks.de/search/de/trial/DRKS00036833/details</a>.</p>