Reliability of clinical ICD-10 diagnoses among electroconvulsive therapy patients with chronic affective disorders

Background and Objectives: Diagnostic reliability is of major concern both to clinicians and researchers. The aim has been to investigate the trustworthiness of clinical ICD-10 affective disorder diagnoses for research purpose. Methods: 150 ECT patients with chronic affective disorders were investigated. A standardized schema for basic anamnesis and the Operational Criteria Checklist for Psychotic and Affective Illness (OPCRIT) were used. The sensitivity, specificity, positive and negative predictive values of clinical affective disorder ICD-10 diagnoses and the formal agreement between clinical ICD-10, OPCRIT ICD-10 and DSM-IV diagnoses were determined using unweighted K-statistics. Results: The sensitivity, specificity, positive and negative predictive values of the clinical bipolar diagnoses was 0.55, 0.75, 0.42 and 0.84, respectively. The sensitivity, specificity, positive and negative predictive values of the clinical unipolar diagnoses was 0.79, 0.55, 0.77 and 0.58, respectively. The agreement between clinical ICD-10 and OPCRIT ICD-10 bipolar vs. non-bipolar diagnoses was low, K = 0.28. The agreement between clinical ICD-10 and OPCRIT ICD-10 unipolar vs. non-unipolar diagnoses was low, K = 0.35. The agreement between OPCRIT ICD-10 and DSM-IV diagnoses, on bipolar vs. non-bipolar disorders was high, K = 0.91, and the agreement on unipolar vs. non-unipolar disorders was fairly high, K = 0.78. Conclusions: This study demonstrates that the reliability of clinical ICD-10 diagnoses of affective disorders from chronic subjects with a history of ECT is problematic despite sample homogeneity on basic clinical, demographic and epidemiological parameters.