A comparison of two psychiatric service approaches: findings from the Consultation vs. Liaison Psychiatry-Study.

Background: Psychiatric comorbidities are common in somatically ill patients. There is a lack of data that can provide clear insights into substantial comparative advantages of different Consultation/Liaison Psychiatry (CLP) services.

Methods: The Consultation versus Liaison Psychiatry-Study collected and analyzed data of 890 primarily somatically ill hospital inpatients presenting with psychiatric symptoms in a prospective observational study design. One group was treated via a liaison-model (LM) with regular consultation hours, the other via an on-demand-model (ODM) with individually requested consultations.

Results: Five hundred forty-five LM and 345 ODM patients were compared. Patients in the LM were, on average, older compared to the patients of the ODM. The vast majority (90.8%) of individuals for whom a psychiatric consultation was requested came from internal medicine. The most common diagnoses were affective disorders (39.3%), organic mental disorders (18.9%), alcohol-induced mental disorders (11.3%) and reactions to severe stress/adjustment disorders (10.4%). Organic mental disorders were significantly more common in patients seen in the LM (24.0% vs. 10.3%, p < 0.001) while affective disorders were more frequently diagnosed in the ODM (46.6% vs. 34.8%, p = 0.001). Patients seen in the ODM were, on average, more severely affected compared to patients seen in the LM and required more extensive treatment. 16.3% of ODM patients were regarded as potentially suicidal; among these, 3.5% were acutely suicidal and 12.8% latently suicidal. Any form of further treatment was required by 93.0% of ODM patients compared to 77.8% in the LM. Pharmacological treatment with benzodiazepines, usually used as short-term treatment, was more frequently prescribed to patients seen in the ODM while patients seen in the LM were more often started on selective serotonin reuptake inhibitors, indicative of long-term treatment.

Conclusions: Patients in need of less acute treatment were considerably less common in the ODM. The data indicate a possible risk of such patients to remain unrecognized. A quasi-liaison model is recommended to be the best suitable and cost-effective way of providing psychiatric care to somatically ill patients with psychiatric comorbidities.