Exploring bias in the measurement of health and social functioning of adults with severe mental health problems due to time, age, and gender

.The Health of the Nation Outcomes Scale (HoNOS) is a measure of health and social functioning of people with severe mental illness. The main aim of this project is to explore the ‘measurement invariance’ of HONOS over time, age and sex – in other words, to explore if people with the same trait levels in behaviour, impairment, symptoms, and/or social functioning receive different scores in HoNOS, just because of their age, gender or time point (biased scores).