Der WHO Wellbeing Index (WHO-5) als Depressivitätsmaß

Der WHO-5 erfasst mit fünf Items psychisches Wohlbefinden, er dient auch als Screeninginstrument zur Erfassung depressiver Symptomatik. Wenige Studien untersuchten diesen Validitätsaspekt jedoch im klinischen Kontext. Ziel der vorliegenden Studie war es, die Messinvarianz des WHO-5 zwischen depressiven und nicht-depressiven Stichproben sowie Art und Spezifität des Zusammenhangs mit Skalen zur Erfassung der Depressionsschwere zu überprüfen. Insgesamt 414 Personen füllten den WHO-5 und das BDI-II aus. Aktuell erfüllten 207 Personen die DSM-IV-Kriterien einer Major Depression (SKID-I). Eine Teilstichprobe erhielt zusätzlich das Beck-Anxiety-Inventory (BAI) und wurde auf der Hamilton-Depression-Rating-Scale (HAM-D) und der Hamilton- Anxiety-Rating-Scale (HAM-A) durch trainierte Rater eingeschätzt. Der WHO-5 wies hohe Messinvarianz bezüglich des Vorliegens/Nichtvorliegens einer Major Depression auf. Er zeigte hohe negative Zusammenhänge mit selbst- und fremdeingeschätzter Depressivität (BDI-II, HAM-D), insbesondere bei milderer und moderater Symptomschwere und auch nach Kontrolle gleichzeitig bestehender Angstsymptomatik. Diese Ergebnisse unterstützen die Verwendung des WHO-5 als Depressionsmaß, zumindest im Bereich milder und mittlerer Depressionsschwere.

Measuring depression with a well-being index: Further evidence for the validity of the WHO Well-Being Index (WHO-5) as a measure of the severity of depression

BACKGROUND: In recent years, the WHO Wellbeing Index (WHO-5) has been used as a screening measure for depression. Nevertheless, research on the validity of this measure in the context of clinical depression is sparse. QUESTIONS: The aim of the present study was to investigate the measurement invariance of the WHO-5 across depressed and non-depressed individuals, as well as the shape and specificity of its relationship to measures of depression severity. METHOD: Of the 414 subjects who completed the WHO-5 and the Beck Depression Inventory-II (BDI-II), 207 had a diagnosis of a major depressive episode (MDE). A subsample also completed the Beck Anxiety Inventory (BAI) and was assessed by clinicians using the Hamilton Depression Rating Scale (HAM-D) and the Hamilton Anxiety Rating Scale (HAM-A). RESULTS: The WHO-5 demonstrated strong measurement invariance regarding the presence or absence of a current MDE. The WHO-5 showed a very high negative association with self- and observer-rated measures of depressive symptoms, especially in the range of mild to moderate symptoms. These associations were still substantial after controlling for measures of anxiety symptoms. LIMITATIONS: In addition to a diagnostic interview, only one measure for self- and observer-rated symptoms of depression was used. Furthermore, the observer-rated measure was only assessed in one subsample that exhibited a somewhat restricted range of depression severity. CONCLUSION: Although this index was originally designed as a measure of well-being, the results support the use of the WHO-5 in the context of depression research.

Factor Structure of the Neck Disability Index

BACKGROUND CONTEXT: The Neck Disability Index frequently is used to measure outcomes of the neck. The statistical rigor of the Neck Disability Index has been assessed with conflicting outcomes. To date, Confirmatory Factor Analysis of the Neck Disability Index has not been reported for a suitably large population study. Because the Neck Disability Index is not a condition-specific measure of neck function, initial Confirmatory Factor Analysis should consider problematic neck patients as a homogenous group. PURPOSE: We sought to analyze the factor structure of the Neck Disability Index through Confirmatory Factor Analysis in a symptomatic, homogeneous, neck population, with respect to pooled populations and gender subgroups. STUDY DESIGN: This was a secondary analysis of pooled data. PATIENT SAMPLE: A total of 1,278 symptomatic neck patients (67.5% female, median age 41 years), 803 nonspecific and 475 with whiplash-associated disorder. OUTCOME MEASURES: The Neck Disability Index was used to measure outcomes. METHODS: We analyzed pooled baseline data from six independent studies of patients with neck problems who completed Neck Disability Index questionnaires at baseline. The Confirmatory Factor Analysis was considered in three scenarios: the full sample and separate sexes. Models were compared empirically for best fit. RESULTS: Two-factor models have good psychometric properties across both the pooled and sex subgroups. However, according to these analyses, the one-factor solution is preferable from both a statistical perspective and parsimony. The two-factor model was close to significant for the male subgroup (p<.07) where questions separated into constructs of mental function (pain, reading headaches and concentration) and physical function (personal care, lifting, work, driving, sleep, and recreation). CONCLUSIONS: The Neck Disability Index demonstrated a one-factor structure when analyzed by Confirmatory Factor Analysis in a pooled, homogenous sample of neck problem patients. However, a two-factor model did approach significance for male subjects where questions separated into constructs of mental and physical function. Further investigations in different conditions, subgroup and sex-specific populations are warranted.