Published online by Cambridge University Press: 16 April 2020
Develop a cross-cultural translation, Swedish to Spanish, of TOOL questionnaire - a previously validated instrument to assess the impact of adverse effects (AE) on the health utilities and health related quality of life (HRQoL) in patients with schizophrenia and bipolar disorder.
TOOL questionnaire has 8 attributes and 4 levels per domain: mood (anxiety and depression), function capabilities, and AE frequently associated with antipsychotics (fatigue-weakness, weight gain, stiffness-tremor, physical restlessness, sexual dysfunction, and vertigo-nausea). Firstly, 4 independent translators carried out the forward-backward translations. Next, draft version was reviewed by an experts panel (5 psychiatrists & 1 GP specialized in HRQoL) and tested in 40 stable patients (20 schizophrenic & 20 bipolar). Comprehension and importance (C/I) of each item were evaluated by a Likert scale ranging from 0 (lowest level) to 4 (highest level).
3 items should be modified to facilitate comprehension: mood, physical restlessness and vertigo-nausea. However, C/I of items mean scores were respectively: mood (3.50/ 2.37); function capabilities (2.58/ 2.03); fatigue-weakness (3.58/ 2.55); weight gain- (3.75/ 2.87); stiffness-tremor (3.65/ 2.61); restlessness (3.37/ 2.62); sexual dysfunction (3.39/ 2.51) and vertigo-nausea (3.56/ 2.44). Only 2 patients (5%) were unable to complete the questionnaire. Internal consistency was high (Cronbach α= 0.87) and neither item ceiling nor floor effects were found.
The Swedish TOOL questionaire was culturally adapted into Spanish. Psychometric analyses are needed to validate this measure in Spain. A multtiatribute utility fuction should be estimated to evaluate AE by using a patients"centered perspective.