MII IG PRO
2027.0.0-ballot.1 - Germany

This page is part of the MII Implementation Guide PRO (v2027.0.0-ballot.1: 2027 Ballot 5) based on FHIR (HL7® FHIR® Standard) R4. This is the current published version in its permanent home (it will always be available at this URL). For a full list of available versions, see the Directory of published versions

GAD-7

Clinical Context

The GAD-7 (Generalized Anxiety Disorder Scale-7) is the standard instrument for screening for generalized anxiety disorder. Seven items capture the frequency of anxiety symptoms over the past two weeks on a four-point scale (0 = not at all, to 3 = nearly every day).

Scoring and interpretation (sum score 0–21, Spitzer et al. 2006):

  • 0–4: minimal anxiety
  • 5–9: mild anxiety
  • 10–14: moderate anxiety — further assessment recommended
  • 15–21: severe anxiety

Relationship to the PHQ family: the GAD-7 comes from the same authors as the PHQ-9 and shares its answer scale. The first two items form the GAD-2, and together with two PHQ-9 items they make up the PHQ-4 — the ultra-short screen for anxiety and depression. This is precisely why the items in the MII PRO module carry the linkIds of the shared PHQ-D block namespace (phq-phq5a…phq-phq5g) rather than an instrument-specific numbering: the same question should carry the same linkId across instruments.

FHIR Implementation

Language strategy: English as the primary language (the original per Spitzer et al. 2006), German texts as translations (PHQ-D, Löwe et al. 2002; validated in over 5,000 people from the German general population).

Questionnaire

Canonical URL: https://www.medizininformatik-initiative.de/fhir/ext/modul-pro/Questionnaire/mii-qst-pro-gad-7

Capabilities: Displayable, Collectable, Calculatable, Extractable, Domain-aligned

Implementation notes:

  • linkIds in the PHQ-D block namespace: phq-phq5a…phq-phq5g, score item phq-gad7-score-total.
  • Answer scale via the shared RuleSet Phq4PointFrequencyAnswerOptions — inline answerOption with the LOINC answer codes of list LL358-3 (LA6568-5…LA6571-9) and ordinal weights 0–3. The same scale as the PHQ-9.
  • Score calculation via FHIRPath: %resource.item.where(linkId.matches('^phq-phq5[a-g]$')).answer.value.weight().sum().
  • LOINC panel 69737-5, score item with LOINC 70274-6.

Item numbering: the ConceptMap mii-cm-pro-gad-7-linkids maps the conventional GAD-7 numbering (items 1–7) onto the canonical linkIds — a reading aid for taking over data from third-party systems.

The complete resource: Questionnaire definition.

Score Representation

  1. Calculated item in the QuestionnaireResponse (linkId: phq-gad7-score-total)
  2. Observation carrying the LOINC code 70274-6
  3. ObservationDefinition: mii-obsdef-pro-score-gad-7 — value range 0–21 {score}, higher = more pronounced anxiety

The four severity bands are documented as qualifiedInterval but not shipped as executable interpretation logic (see Scoring).

Not included: a PROMIS anxiety T-score conversion. Score conversions between instruments will be modelled as a CQL library rather than as a FHIRPath expression in the questionnaire.

License

GAD-7 © Pfizer Inc., developed by Spitzer, Kroenke, Williams and Löwe — freely available; no permission required for reproduction, translation, display or use. German version: PHQ-D (Löwe, Spitzer, Zipfel & Herzog 2002).

Sources

  • Spitzer RL, Kroenke K, Williams JBW, Löwe B. A brief measure for assessing generalized anxiety disorder: the GAD-7. Archives of Internal Medicine 2006;166(10):1092–1097. doi:10.1001/archinte.166.10.1092
  • Löwe B, Decker O, Müller S, et al. Validation and standardization of the Generalized Anxiety Disorder Screener (GAD-7) in the general population. Medical Care 2008;46(3):266–274. doi:10.1097/MLR.0b013e318160d093
  • Esser P, Hartung TJ, Friedrich M, et al. The Generalized Anxiety Disorder Screener (GAD-7) and the anxiety module of the Hospital and Depression Scale (HADS-A) as screening tools for generalized anxiety disorder among cancer patients. Psycho-Oncology 2018;27(6):1509–1516. doi:10.1002/pon.4681