Primary care consultation liaison and the rate of psychiatric hospitalizations: a countrywide study in Chile.

Objectives: To assess the quality of consultation liaison across all primary health care centers in Chile, and its potential relationship with the psychiatric hospitalization rate.

Methods: We carried out a countrywide ecological cross-sectional study on 502 primary health centers in 275 municipalities (87.3% of total primary health centers in Chile) during 2009. We characterized the presence of consultation liaison using four criteria: availability, frequency, continuity of participants, and continuity across care levels. We also created a dichotomous variable called "optimal consultation liaison" for when all four criteria were met. A quasi-Poisson regression model was used to estimate the rate of hospitalization due to different psychiatric disorders, adjusting by population attributes.

Results: Of the primary health centers, 28.3% of them had had optimal consultation liaison during the preceding year, concentrated in the poorest and richest municipalities. Continuity of care was the criterion that was met least often (38.3%). The presence of optimal consultation liaison at the municipal level was associated with fewer psychiatric discharges, with the following incidence rate ratios and 95% confidence intervals (CIs): schizophrenia, 0.65 (95% CI: 0.49-0.85); other psychoses, 0.68 (95% CI: 0.52-0.89); and personality disorders, 0.66 (95% CI: 0. 49-0.89). Municipalities with optimal consultation liaison showed 2.44 fewer total psychiatric discharges per 10 000 inhabitants, although without reaching statistical significance (-0.85 to 5.70).

Conclusions: Using a nationally representative sample, we found that consultation liaison in primary care was associated with having fewer psychiatric hospitalizations. More studies are required to understand the role of each component of consultation liaison.