Reliability and Validity of the Short Version of Udvalg for Kliniske Undersogelser in Antipsychotic Treatment.

The aim of this study was to develop a reliable and valid short version of the Udvalg for Kliniske Undersogelser (UKU) to efficiently evaluate the side effects of antipsychotics in patients with schizophrenia. This multi-site study included 10 hospitals, which included 331 inpatients and outpatients diagnosed with schizophrenia. UKU, Clinical Global Impression-Severity (CGI-S), Personal and Social Performance (PSP) and dosage of paliperidone were collected. The predictive validity of the UKU-short version, as well as that of the CGI-S, PSP and paliperidone dosages, was analyzed using structural equation modeling (SEM), latent growth models (LGM), and confirmatory factor analysis to test its content and construct validity. The UKU-short included nine-items of sedation, reduced sleep, rigidity, tremor, akathisia, headache, reduced salivation, constipation and orthostatic dizziness, and has good construct and content validity over time. Confirmatory factor analysis showed good construct validity, with the psychic, neurological and autonomic side effect dimensions having correlations between 0.60 and 0.71. The predictive validity of the short-version UKU for psychiatric symptoms (CGI-S), quality of life (PSP) and dosage showed that the effects of drug dosage were negligible, and only neurological side effects were associated with psychiatric symptoms and quality of life. The UKU-short showed good content, construct and predictive validity. It is a more time-efficient instrument than the original UKU. This study only included patients treated with paliperidone, larger scale studies is needed to validate the UKU-short in detection of side effects in routine clinical practice to prevent non-adherence in patients with schizophrenia.