The Hamburg-Hannover Agitation Scale (H2A): Development and validation of a self-assessment tool for symptoms of agitation.

Background: Agitation has long been underestimated as a symptom occurring across psychiatric disorders. While several instruments exist for highly specific clinical target groups (e.g., dementia, traumatic brain injury), no tool captures agitation in a broader range of psychiatric patients. The Hamburg-Hannover Agitation Scale (H2A) has been designed to satisfy this demand. This study concentrated on the development and validation of the scale in a psychiatric and a healthy control sample.

Methods: The H2A was developed, tested in an expert sample, and revised. The German version was validated in a study involving two clinical institutions. Patients (n = 180) completed the H2A and several other questionnaires in order to test for congruent and discriminant validity. Healthy subjects (n = 685) completed the H2A only. The H2A was translated into English.

Results: The H2A showed very satisfying quality criteria (reliability, selectivity, item difficulty) and regression analysis demonstrated the H2A's ability to distinguish between subjects with a psychiatric diagnosis and healthy subjects with or without psychiatric record. Factor analysis revealed a three-factorial structure representing a physiological/somatic, a mental and a mixed ('psychophysiological') dimension of agitation.

Limitations: Although validation showed promising quality criteria and predictive value of the H2A, calibration tests with bigger and more balanced sample sizes are necessary.

Conclusions: Agitation has become more clinically relevant as a symptom occurring in various affective disorders, yet its assessment is limited. The H2A was developed in order to meet this need. Validation of the H2A revealed very satisfactory item and scale quality criteria promoting its utility.