The factor structure and psychometric properties of the Clinical Outcomes in Routine Evaluation – Outcome Measure (CORE-OM) in Norwegian clinical and non-clinical samples

Abstract

BackgroundThe Clinical Outcomes in Routine Evaluation - Outcome Measure (CORE-OM) is a 34-item instrument developed to monitor clinically significant change in out-patients. The CORE-OM covers four domains: well-being, problems/symptoms, functioning and risk, and sums up in two total scores: the mean of All items, and the mean of All non-risk items. The aim of this study was to examine the psychometric properties of the Norwegian translation of the CORE-OM.MethodsA clinical sample of 527 out-patients from North Norwegian specialist psychiatric services, and a non-clinical sample of 464 persons were obtained. The non-clinical sample was a convenience sample consisting of friends and family of health personnel, and of students of medicine and clinical psychology. Students also reported psychological stress. Exploratory factor analysis (EFA) was employed in half the clinical sample. Confirmatory (CFA) factor analyses modelling the theoretical sub-domains were performed in the remaining half of the clinical sample. Internal consistency, means, and gender and age differences were studied by comparing the clinical and non-clinical samples. Stability, effect of language (Norwegian versus English), and of psychological stress was studied in the sub-sample of students. Finally, cut-off scores were calculated, and distributions of scores were compared between clinical and non-clinical samples, and between students reporting stress or no stress.ResultsThe results indicate that the CORE-OM both measures general (g) psychological distress and sub-domains, of which risk of harm separates most clearly from the g factor. Internal consistency, stability and cut-off scores compared well with the original English version. No, or only negligible, language effects were found. Gender differences were only found for the well-being domain in the non-clinical sample and for the risk domain in the clinical sample. Current patient status explained differences between clinical and non-clinical samples, also when gender and age were controlled for. Students reporting psychological distress during last week scored significantly higher than students reporting no stress. These results further validate the recommended cut-off point of 1 between clinical and non-clinical populations.ConclusionsThe CORE-OM in Norwegian has psychometric properties at the same level as the English original, and could be recommended for general clinical use. A cut-off point of 1 is recommended for both genders.

A randomized controlled trial of a six-session cognitive behavioral treatment of emotional disorders in adolescents 14–17 years old in child and adolescent mental health services (CAMHS)

“…CORE has shown good psychometric properties [52,53]. A validation study on a Norwegian sample concluded that CORE-OM has the same psychometric properties as the English version [52,53]. The internal consistency for the CORE-OM total score in the present sample was excellent (Cronbach's α = .92).…”

“…Clinical Outcome in Routine Evaluation-Outcome Measure (CORE-OM) [51], Norwegian language version [52], was used as a secondary outcome measure for general symptom pressure and risk of suicide and self-harm and was distributed at enrollment and end of therapy. CORE-OM is a 34-item questionnaire with items using a 5-point Likert scale from 0 to 4, with higher scores indicating an increased symptom pressure.…”

“…Skre et al [52] suggested a cutoff point of 1 for discriminating between clinical and non-clinical populations. CORE has a reader interface age of 14 years in Norwegian adolescents [52] and can thus be applied in this sample. CORE has shown good psychometric properties [52,53].…”

“…CORE has a reader interface age of 14 years in Norwegian adolescents [52] and can thus be applied in this sample. CORE has shown good psychometric properties [52,53]. A validation study on a Norwegian sample concluded that CORE-OM has the same psychometric properties as the English version [52,53].…”

Comparison of psychiatric comorbidity in treatment‐seeking, opioid‐dependent patients with versus without chronic pain

“…A threshold of ≥ 34 was used to indicate clinical status . It has been validated in samples from the general population and in clinical samples . Its validity is yet to be assessed in opioid‐dependent populations, and the CORE‐OM is yet to be compared with ‘gold standard' diagnostic instruments, such as the Composite International Diagnostic Interview (CIDI); however, it is shown to have a strong positive correlation (0.75) with the GHQ .…”