Health-related quality of life prediction using the self-evaluation of negative symptoms scale (SNS) in patients with schizophrenia

Abstract

Background: Assessing health-related quality of life is essential to understand the subjective burden of disease. The self-evaluation of the negative symptoms scale (SNS) is a valuable tool for screening negative symptoms and has been validated in Lithuania. This study aimed to determine the predictive value of SNS for the quality of life in patients with schizophrenia. Methods: Patients with schizophrenia in a stable state (non-psychotic) were included in this study. Negative symptoms were evaluated using SNS and quality of life using the Short Form health survey questionnaire (SF-36). The area under the Receiver Operating Characteristic (AROC) was calculated for the total score of SNS and SF-36 subscores. Results: Total of 67 patients with schizophrenia were included in the study. The SNS total score showed moderate predictive value for quality of health related to vitality (AROC=0.749 +/- 0.061. p=0.001), social function (AROC=0.698 +/- 0.066, p=0.007) and mental wellbeing (AROC=0.809 +/- 0.053, p<0.001). Cut-off score of 17.5 predicted that the SF-36 mental wellbeing score would be<= 50 with a sensitivity of 83% and specificity of 65%. Cut off score of 16.5 predicted that the SF-36 vitality and social function scores would be <=50 with a sensitivity of 77% and 71% and specificity of 64% and 60% accordingly. Conclusion: SNS has the potential to predict health-related quality of life in patients with schizophrenia. Future research to support this is needed.