Computerized adaptive testing in primary care: CATja

In this dissertation, research is described that has been conducted to develop an online test battery (named CATja) that supports general practitioners and mental health assistants (MHAs) in deciding which level of care suits their clients that experience diverse psychological complaints best. Would treatment in general practices be sufficient, or is referral to generalist or specialist mental health care required? For this, CATja generates a profile of complaints (e.g. depression) and strengths (e.g. emotional support). In order to incorporate the valuable experience, knowledge and wishes of the intended users, CATja has been developed in close collaboration with MHAs from the beginning.
The innovative feature of CATja is its adaptive character, making it very efficient in practice. Adaptive means that follow-up questions during test administration are tailored to answers given to preceding questions. After each answer provided, the extent to which a certain domain (e.g. fear) is present in a client is newly computed and it is determined which follow-up question yields most information given this level of fear. Questions that provide little information are skipped. One could say that 'the behavior' of a 'computerized adaptive test' (CAT, hence the name CATja), as it were, mimics the behavior of an experienced interviewer.
The first version of CATja includes five psychopathology domains: anxiety, depression, distress (general stress symptoms), and negative and positive symptoms of psychosis. In addition, MHAs can map the quality of clients’ social networks by use the domains emotional support and friendship. First results of our implementation study are promising.