Using the INTERMED complexity instrument for a retrospective analysis of patients presenting with medical illness, substance use disorder, and other psychiatric illnesses.

Background: The financial and treatment challenges of complex patients must be addressed with adequate assessment and evaluation. The INTERMED complexity instrument (INTERMED) has been developed for this purpose, but to date has not been used retrospectively. The current study represents a retrospective validity investigation of INTERMED with patients with substance use disorder comorbid with other psychiatric and medical conditions (triple diagnoses). Such patients were expected to generate high complexity scores on the INTERMED instrument.

Methods: Information on 66 patients with triple diagnoses was submitted to the INTERMED complexity grid. These data were subjected to cluster analysis and other analytic procedures.

Results: Total INTERMED scores reflected elevated complexity for patients with triple diagnoses. As a group, they represented a single cluster of complex patients.

Conclusions: The validity of the INTERMED complexity assessment was corroborated in relation to retrospective data. In addition to elevations in the biological domain that hospital personnel typically confront, findings related to coping deficiencies and problems in living conditions were noteworthy in requiring comprehensive interventions.