Aktuelle Validierungsdaten und Ergebnisse zur Prävalenzanalyse, prädiktiven Aussagekraft, klinischen Anwendbarkeit und Eignung zur therapeutischen Verlaufskontrolle der Hospital Anxiety and Deprssion Sclae (HADS) in der somatischen Medizin

Abstract

Aim of this dissertation is to investigate empirical data representing the psychometric properties and applications of the HADS in various fields of clinical somatic medicine. The Hospital Anxiety and Depression Scale (HADS) was designed as a screening tool in psychodiagnostics for use among patients in somatic medicine. By means of two subscales it covers anxious and depressive symptoms. It has no alternate diagnosis task but to act with their dimensional approach first as a pioneering instrument to conduct conspicuous results to secondary psychodiagnostics. Especially light and subtle psychological abnormalities shall be detected which play a well-documented role in the pathogenesis in many somatic diseases. The results of analysis of the quality criteria of the HADS can be seen as evidence of validity and reliability. The case identification results indicate in the majority of cases a satisfactory sensitivity and specificity, in the few studies showing significantly lower sensitivities and specificities methodological deficits in creating and validating international HADS versions could be responsible. The task of the HADS as a screening tool is not to reach perfected specifities or sensitivities. The choice of the cut-off values are still subject to fluctuations but you can define an orientation that in many cases a cut-off for both subscales (HADS-D / A) of ≥8 is appropriate. The investigations of the individual validity showed mostly satisfactory results. The correlation to other construct related methods corresponds in a medium to high context. The discriminative validity indicates that there consists a relatively high cross-correlation between the two HADS subscales. This should not be interpreted to the disadvantage of the HADS but can be explained by frequently occurring cases of comorbid anxiety and depression. The HADS also shows dependencies of age and gender. Recent studies show that the distribution of anxiety and depression in women and men is quite different. The up to now accepted above-average incidence of depressive disorders in women could not be confirmed in all studies and should be the basis for further studies. Factor analysis yielded in most cases a two-factor structure of the HADS. Nevertheless it represents a point of discussion as several studies also found a one- or three-factor structure. Even with the factorial validity having not yet been finally clarified at this point a number of recent publications confirm the two-factor structure. The examination of reliability of the HADS yielded good results and indicates a high internal consistency of the scale. The examination of the retest reliability speaks for acceptable stability of the HADS averages over defined periods of time. Follow-up studies on psychosocial and therapeutic interventions examine the sensitivity to change of the scale. In particular the study of Hinz et al. (2009) confirmes good results in change measurements of the HADS. In psychodiagnostics there is a special interest in comparing various screening tools. The HADS is frequently compared with other instruments such as the PHQ, the GHQ and BDI. The PHQ as a relatively new instrument poses a challenge regarding its possibilities and validity specially when detecting depressive episodes. It remains unclear whether this is an advantage in terms of therapeutic approaches or the prognosis. Nevertheless the HADS gains acceptance between other instruments and its position in psychodiagnostics is consolidated. There are a number of publications on the studies of HADS in different patient groups. Almost all fields of somatic medicine show results with the HADS. Cardiology and oncology patient groups are of particular attention. It can be assumed that about 10% -25% of cardiac patients have significantly higher scores on the HADS anxiety or depression scale (HADS-A/D ≥11). In oncologic patients you can expect up to 30% at the same cut-off. In addition to the purely epidemiological data in many studies correlations between somatoform disorders of different diseases and certain examined psychosocial criteria were investigated. On the one hand especially studies to determine mortality have shown high correlations with depression in cardiac patients. On the other hand those studies need to be mentioned which have shown a positive correlation between distinct somatic complaints, noticeable mental disorders and a corresponding limited quality of life of the patients. In addition the HADS finds increasing use in follow-up examinations during psychosocial or psychotherapeutic interventions or pharmacotherapeutic treatments. With research for new drug therapies intensifying and new drugs being administered to the patients the higher will be the interest in testing a treatment result or progress with the help of measurement methods. To all studies it is common to pursue the aim of establishing a psychodiagnostics in somatic medicine if there exists a presumption of a comorbid mental disorder and then to enable a necessary, intensive and individual further diagnosis and best possible therapy.