Scale descriptor selection for Taiwan-version of questionnaire of World Health Organization quality of life

Objectives: This study is to select appropriate descriptors for Taiwan-version of World Health Organization quality of life questionnaire (WHOQOL) Methods: WHOQOL consists of four kinds of response scales: capacity, frequency, intensity, and evaluation. Each response scale has five ordinal descriptors including two anchors at extreme levels and three intermediates. We invited experts to decide the two anchors for extreme levels, and then selected 156 outpatients and healthy persons from 10 hospitals in Taiwan to place each descriptor on a 10 centimeter line according to where they think each descriptor ties in relation to the two anchors. Results: Five most appropriate Chinese descriptors were 'Completely not', 'A little', 'Moderately', 'Very' and 'Completely' for capacity; 'Never', 'Seldom', 'Half', 'Very often' and 'Always' for frequency; 'Completely not', 'Slightly', 'Moderately', 'Very much' and 'Extremely' for intensity; and 'Extremely dissatisfied', 'Dissatisfied', 'Moderately satisfied', 'Satisfied' and 'Extremely satisfied' for evaluation. Test-retest reliability was moderate on the average but varied among descriptors. However, there were no differences between their mean values of test and retest. Conclusions: These selected descriptors are suitable for Taiwan-version of WHOQOL and other use of health profile assessment of quality of life.