Language-related differential item functioning between English and German PROMIS Depression items is negligible.

To investigate differential item functioning (DIF) of PROMIS Depression items between US and German samples we compared data from the US PROMIS calibration sample (n = 780), a German general population survey (n = 2,500) and a German clinical sample (n = 621). DIF was assessed in an ordinal logistic regression framework, with 0.02 as criterion for R -change and 0.

Using Patient Health Questionnaire-9 item parameters of a common metric resulted in similar depression scores compared to independent item response theory model reestimation.

Objectives: To investigate the validity of a common depression metric in independent samples.

Study Design And Setting: We applied a common metrics approach based on item-response theory for measuring depression to four German-speaking samples that completed the Patient Health Questionnaire (PHQ-9). We compared the PHQ item parameters reported for this common metric to reestimated item parameters that derived from fitting a generalized partial credit model solely to the PHQ-9 items.

[Review Model for the Assessment of Psychometric Instruments--Recommendations of the German College of Psychosomatic Medicine (DKPM)].

Objectives: Psychometric instruments are commonly applied in psychotherapeutic research and care for the baseline assessment of symptoms, the planning of therapeutic interventions, the assessment of the longitudinal course of symptoms and outcomes of therapeutic interventions as well as quality management of care. Psychometric properties as well as economic aspects should be considered in the selection of specific instruments. It is assumed that users of psychometric instruments face a great variety of instruments and related information.

Assessing somatic symptom burden: a psychometric comparison of the patient health questionnaire-15 (PHQ-15) and the somatic symptom scale-8 (SSS-8).

Objective: The Patient Health Questionnaire-15 (PHQ-15) is a frequently used questionnaire to assess somatic symptom burden. Recently, the Somatic Symptom Scale-8 (SSS-8) has been published as a short version of the PHQ-15. This study examines whether the instruments' psychometric properties and estimates of symptom burden are comparable.

Standardization of depression measurement: a common metric was developed for 11 self-report depression measures.

Objectives: To provide a standardized metric for the assessment of depression severity to enable comparability among results of established depression measures.

Study Design And Setting: A common metric for 11 depression questionnaires was developed applying item response theory (IRT) methods. Data of 33,844 adults were used for secondary analysis including routine assessments of 23,817 in- and outpatients with mental and/or medical conditions (46% with depressive disorders) and a general population sample of 10,027 randomly selected participants from three representative German household surveys.

Health-related quality of life, depression, and anxiety in patients with autoimmune hepatitis.

Background & Aims: Improving health related quality of life (HrQoL) in patients with chronic diseases such as autoimmune hepatitis (AIH) should be a major treatment goal. However, little is known on the HrQoL in patients with AIH, and the topic is not given attention in current practice guidelines. We therefore conducted a single center study evaluating HrQoL in 103 consecutive outpatients with AIH.

[Computer adaptive tests in medicine].

Measurement of Patient-reported Outcomes (PRO) still lacks behind clinical standards. Most established tools are also either too burdensome or too imprecise to be used in clinical practice. Item Response Theory (IRT) methods and Computer Adaptive Tests (CAT) promise to overcome these shortcomings.

Impact of cross-calibration methods on the interpretation of a treatment comparison study using 2 depression scales.

Background: Many questionnaires assessing depressive symptoms are available. Most of these questionnaires are constructed based on classical test theory, making comparisons of individual scores difficult. Item response theory (IRT) allows the comparison of scores from different instruments.

A 4-item measure of depression and anxiety: validation and standardization of the Patient Health Questionnaire-4 (PHQ-4) in the general population.

Background: The 4-item Patient Health Questionnaire-4 (PHQ-4) is an ultra-brief self-report questionnaire that consists of a 2-item depression scale (PHQ-2) and a 2-item anxiety scale (GAD-2). Given that PHQ-4, PHQ-2, and GAD-2 have not been validated in the general population, this study aimed to investigate their reliability and validity in a large general population sample and to generate normative data.

Methods: A nationally representative face-to-face household survey was conducted in Germany in 2006.