Development and psychometric properties of a five-language multiperspective instrument to assess clinical decision making style in the treatment of people with severe mental illness (CDMS)

A participatory approach was chosen for instrument development which followed 10 sequential steps proposed in a current guideline of good practice for the translation and cultural adaptation of measures. Following item analysis, reliability, validity, and long-term stability of the CDMS were examined using Spearman correlations in a sample of 588 people with severe mental illness and 213 mental health professionals in 6 European countries (Germany, UK, Italy, Denmark, Hungary, and Switzerland).In both patient and staff versions, the two CDMS subscales “Participation in Decision Making” and “Information” reliably measure distinct characteristics of decision making. Validity could be demonstrated to some extent, but needs further investigation.Together with two other five-language patient- and staff-rated measures developed in the CEDAR study (ISRCTN75841675) – “Clinical Decision Making in Routine Care” and “Clinical Decision Making Involvement and Satisfaction” – the CDMS allows empirical investigation of the complex relation between clinical decision making and outcome in the treatment of people with severe mental illness across Europe.Decision-making in health care has been conceptualized as a process taking place between patient and health professional on a continuum between “paternalistic”, “shared”, and “informed” [1,2]. Shared decision making has received much attention in research and practice since its first mention 30 years ago [3]. Substantial evidence has accumulated in recent decades for clinical decision making in acute (e.g. heart attack, stroke) and long-term physical conditions (e.g. cancer and fibromyalgia) [4-10]. Shared decision making has been termed an ethical imperative [11] and is recommended in guidelines for the treatment of people with schizophrenia [12].However, knowledge about clinical decision making in the treatment of people with mental illness is still limited. Most importantly, apart from a few studies [13], little is known about the