Association between the timing of consultation-liaison psychiatry interventions and the length of stay in general hospital.

Background: Psychiatric comorbidities are frequent in patients admitted in general hospital and are associated with greater lengths of stay (LOS). Early consultation-liaison psychiatry (CLP) interventions may reduce the LOS but previous studies were underpowered to allow subgroup analyses and have generally not considered the severity of the condition for which patients were admitted ('disease severity').

Aims: To investigate the association between the timing of CLP interventions and LOS in a general hospital.

Method: We retrospectively included 4500 consecutive patients admitted in non-psychiatric wards of a university hospital between 2008 and 2016 who had a first CLP intervention. We used general linear models to examine the association between the referral time, defined as log(days before the consultation)/log(LOS), and log(LOS), adjusting for age, gender, year of admission, place of residence, main psychiatric diagnosis, admission to the intensive care unit (ICU), main physical condition and disease severity.

Results: Referral time was associated with log(LOS) (β = 0.31; <0.001), notably for older patients (β = 0.43; <0.001) and those admitted to the ICU (β = 0.50; <0.001), but not for those with psychotic disorders (β = -0.20; = 0.10). The association was confirmed when considering the expected LOS for each patient. For instance, for an expected LOS of 10 days, a CLP intervention on day 3 compared with day 6 was associated with a reduction of the actual LOS of 2.4 days.

Conclusions: Earlier CLP interventions were associated with a clinically significant shorter LOS in a large population even after adjusting for disease severity. Early CLP interventions may have benefits for both patients and health-related costs.