M124. ASSOCIATION OF CHRONIC PHYSICAL MULTIMORBIDITY WITH THE EFFICACY OF TREATMENT IN DIFFERENT SCHIZOPHRENIA SPECTRUM DISORDERS
Authors: Filipčić Igor , Filipčić Ivona Šimunović , Bajić Žarko 
Published: May 2020

Abstract

Background
Patients with schizophrenia spectrum disorders (SSD) have higher prevalence of chronic physical illness (CPI) and a substantially reduced life expectancy compared with the general population. Despite the increasing amount of research in this area, the effect on psychiatric treatment outcome is still not clear. Some research reported significant associations between several CPIs and different SSD treatment outcomes, whereas the remaining study did not. The objective of the current study is to assess differences in the association of the number of CPI with the overall number of psychiatric rehospitalization in specific SSD diagnosis.

Methods
We conducted a cross-sectional study of 354 patients diagnosed with SSD (ICD10): 135 schizophrenia, 71 acute and transient psychotic disorder, 57 schizoaffective disorder, 68 unspecified unorganic psychosis, 23 other (persistent delusional disorder, schizotypal disorder). The primary outcome was the association of the number of CPI with the number of psychiatric rehospitalization since the diagnosis, as the surrogate outcome for the treatment success, adjusted for the time from diagnosis, age, and gender of participants.

Results
Mean number of CPI adjusted for the time from diagnosis, age, and gender was not significantly nor clinically relevantly different between particular SSD diagnosis (F(5,345)=0.70; p=0.620). It was 1.7 in schizophrenia, 1.5 in acute and transient psychotic disorder, 1.4 in schizoaffective disorder, 1.8 in unspecified unorganic psychosis, 1.0 in persistent delusional disorder and 1.9 in schizotypal disorder. The mean number of CPI adjusted for the same three potential confounders was significantly different between particular SSD diagnosis (F(5,345)=2.78; p=0.018). It was 6.7 in schizophrenia, 3.8 in acute and transient psychotic disorder, 7.3 in schizoaffective disorder, 4.8 in unspecified unorganic psychosis. However, the association of the number of CPI with the psychiatric rehospitalizations, adjusted for the previously stated three confounders, was significant and clinically relevant only in participants diagnosed with schizophrenia. In these participants, an increase of one CPI was associated with the 2.3 (95% CI 1.2 to 3.5) more psychiatric rehospitalizations (p&lt;0.001). In participants diagnosed with other specific SSD the association of the number of CPI was not significantly associated with the number of psychiatric rehospitalizations. Moreover, on this particular sample level, it was negative, meaning that more CPI was associated with the lower number of psychiatric rehospitalization in all other SSD except in the case of unspecified nonorganic psychosis.

Discussion
In this cross-sectional study, we observed that the hypothesis of the effect of the number of CPI on the SSD treatment outcomes is valid only in the case of schizophrenia. Further research is needed to clarify whether additional psychological distress is related to the additional burden of multimorbidity.