Exploring the item sets of the Recovering Quality of Life (ReQoL) measures using factor analysis

Purpose This paper presents two studies exploring the latent structure of item sets used in the development of the Recovering Quality of Life mental health outcome measures: ReQoL-10 and ReQoL-20. Method In study 1, 2262 participants completed an initial set of 61 items. In study 2, 4266 participants completed a reduced set of 40 items. Study 2 evaluated two formats of the questionnaires: one version where the items were intermingled and one where the positively worded and negatively worded items were presented as two separate blocks. Exploratory and confirmatory factor analyses were conducted on both datasets where models were specified using ordinal treatment of the item responses. Dimensionality based on the conceptual framework and methods effects reflecting the mixture of positively worded and negatively worded items were explored. Factor invariance was tested across the intermingled and block formats. Results In both studies, a bi-factor model (study 1: RMSEA = 0.061; CFI = 0.954; study 2: RMSEA = 0.066; CFI = 0.971) with one general factor and two local factors (positively worded questions and negatively worded questions) was preferred. The loadings on the general factor were higher than on the two local factors suggesting that the ReQoL scale scores can be understood in terms of a general factor. Insignificant differences were found between the intermingled and block formats. Conclusions The analyses confirmed that the ReQoL item sets are sufficiently unidimensional to proceed to item response theory analysis. The model was robust across different ordering of positive and negative items

Standard set of patient-reported outcomes for personality disorder

Purpose The purpose of the article is to present standard set of outcomes for people with personality disorder (PD), in order to facilitate patient outcome measurement worldwide. Methods The International Consortium for Health Outcomes Measurement (ICHOM) gathered a multidisciplinary international working group, consisting of 16 experts, including clinicians, nurses, psychologists, methodologists and patient representatives, to develop a standard set of outcome measures for people with PD. The Delphi method was used to reach consensus on the scope of the set, outcome domains, outcome measures, case-mix variables and time points for measuring outcomes in service users. For each phase, a project team prepared materials based on systematic literature reviews and consultations with experts. Results The working group decided to include PD, as defined by International Classification of Diseases 11th revision (ICD-11). Eleven core outcomes and three optional outcomes across four health domains (mental health, behaviour, functioning and recovery) were defined as those relevant for people with PD. Validated measures for the selected outcomes were selected, some covering more than one outcome. Case-mix variables were aligned to other ICHOM mental health standard sets and consisted of demographic factors and those related to the treatment that people received. The group recommended that most outcomes are measured at baseline and annually. Conclusion The international minimum standard set of outcomes has the potential to improve clinical decision making through systematic measurement and comparability. This will be key in improving the standard of health care for people with PD across the world