Prevalence and correlates of cognitive impairment among patients with schizophrenia attending psychiatry outpatient clinics at Teaching hospital – Karapitiya

Abstract

INTRODUCTION AND OBJECTIVES: Cognitive impairment is considered a core feature of schizophrenia. This study was designed to estimate the prevalence of cognitive impairment among patients with schizophrenia, to assess the degree of impairment in individual cognitive domains and to identify its sociodemographic and clinical correlates in a Sri Lankan setting. METHODS: A sample of 140 diagnosed patients with schizophrenia was selected from the psychiatry outpatient clinics at Teaching Hospital, Karapitiya. Their cognitive functions were assessed using Addenbrooke’s Cognitive Examination – III Sinhala version (ACE-III-S). Participants who scored below 85.5 in ACE-III-S were categorized as having significant cognitive impairment. Multiple linear regression analysis was conducted to assess correlates with level of significance measured at p = 0.05. RESULTS: In this sample, 89.3% of the participants scored below ACE-III-S cut-off (95% CI [84.09,94.47]). Statistical comparison of proportions of the sample which had impairment in each cognitive domain (attention 60%, memory 65.7%, fluency 55%, language 61.4%, and visuospatial skills 63.6%) did not show a significant difference. The final model of regression analysis showed that patients with shorter duration of formal education (p = <0.001), longer duration of illness (p = <0.001) and higher dose of antipsychotics (p = 0.034) had higher cognitive impairment. CONCLUSION: Nearly nine out of ten people with schizophrenia suffer from significant cognitive dysfunction. The evaluated cognitive domains have been affected equally. The results of this study emphasize the importance of introducing routine cognitive assessment protocols, improving facilities available for cognitive rehabilitation and more frequent review of antipsychotic medications.