Spanih Validation of TOOL Questionnaire: A New Instrument to Assess Quality of Life in Patients with Schizophrenia and Bipolar Disorder

Abstract

Objective:

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.

Methods:

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).

Results:

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.

Conclusions:

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.