"Tacklit"Tacklit: General Anxiety Disorder 7 (GAD-7) background and scoring
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GAD-7

General Anxiety Disorder 7 assessment

What is the GAD 7 assessment and what does it test for?

General Anxiety Disorder 7 assessment, usually shortened to GAD 7, is a self-administered easy-to-use questionnaire designed to measure the severity of certain anxiety disorders. The screening tool is able to decipher the presence of a clinically significant anxiety disorder including: General Anxiety Disorder, Panic Disorder, Social Anxiety Disorder and Post Traumatic Stress Disorder.

When should the GAD 7 be used?

The GAD 7 should be used to establish the presence of anxiety disorders using self reported symptoms experienced in the 2 weeks prior to the assessment. The effectiveness of the GAD 7 has been proven in outpatient settings. It should not be used to determine historical symptoms, acute psychosis, depression or suicidal symptoms. It can be used as a diagnostic tool alongside professional clinical assessment. It may be used to help medical professionals categorise anxious symptoms, or to deduce the pathway of treatment required for an individual.

The GAD 7 can also be used as a screening measure to monitor treatment outcomes, patient scores are likely to decrease with effective treatments.

How is the GAD 7 scored?

The GAD 7 is a 7 part questionnaire from which the patient chooses the most appropriate answer on a 4 point scale: 0 (not at all) to 3 (nearly every day). The lowest score possible is 0 and the highest score is 28. The relationship between scores and severity of anxiety is linear, meaning a low score equates to lower levels of distress and vice versa.

It is worth noting, some research has found the first 4 questions to be more heavily weighted towards a diagnosis than the final 3. In depth analysis of patient’s responses should accompany their raw final score calculation.

Answers and scores:

  • not at all: 0
  • several days: 1
  • more than half the days: 2
  • nearly every day: 3

Score Interpretation

When used as a screening tool, a cut-off score of 10 or higher indicates the need for further evaluation. This cut-off has a sensitivity of 89% and a specificity of 82% for generalised anxiety disorder.

General cut off points for severity markers are as follows:

  • 0-4: no anxiety disorder
  • 5-9: mild anxiety disorder
  • 10-14: moderate anxiety disorder
  • 15+: severe anxiety disorder

It has also been found to have moderate sensitivity and specificity for other anxiety related disorders when using a cut-off score of 8:

  • Panic Disorder: Sensitivity 74%, Specificity 81%
  • Social Anxiety Disorder: Sensitivity 72%, Specificity 80%
  • Post-Traumatic Stress Disorder: Sensitivity 66%, Specificity 81%

The use of the GAD 7 on women or during pregnancy may require further investigation using a cut off score of 7.

Evidence and research supporting the GAD 7

The GAD 7 is a widely used, well-validated and highly useful clinical measure of anxiety disorder symptoms. It has been validated for use in primary care and for use with the general population. It is favoured due to its brevity and excellence in predicting and grading anxiety related disorders. As with all outcome measures, it has limitations and should be used alongside other tools and professional clinical assessment.

There has been research done outlining the difference in diagnostic weighting of each question. Each patient's response and final score should be considered alongside exactly which questions they scored highly on. For example, the first 4 questions have been said to identify anxious disorders more so than the final 3 questions.

The GAD 7 is commended for its ability to highlight moderate to severe anxiety disorders but it is less reliable in those with mild symptoms and deeper professional evaluation should always accompany the completion of the GAD 7.

What questions does the GAD 7 ask?

  • Over the last 2 weeks, how often have you been bothered by any of the following problems?
  • Feeling anxious or on edge?
  • Not being able to stop or control worrying?
  • Worrying too much about different things?
  • Trouble relaxing?
  • Being so restless that it is hard to sit still?
  • Becoming easily annoyed or irritable?
  • Feeling afraid as if something awful might happen?

An optional extra question which is not counted in the final calculation is often:

Ask the patient: how difficult have these problems made it to do work, take care of things at home, or get along with other people? (Not at all/somewhat difficult/very difficult/extremely difficult)

This is a good indicator of the patient’s global impairment to accompany their final score.

References:

  • Swinson RP (2006) The GAD-7 scale was accurate for diagnosing generalised anxiety disorder. Evidence Based Medicine. 11(6):184
  • Spritzer RL, Kroenke K, Williams JB (2006) A brief measure for assessing generalised anxiety disorder: the GAD-7. Archives Intern Med. 166(1):1092-7
  • Kroenke K, Spitzer RL Williams JB (2007) Anxiety Disorders in primary care: prevelance impairment, comorbidity and detection. Annual of Intern Med. 146(5):317-25
  • Ruiz MA, Zamorano E, Garcia-Campayo J (2011) Validity of the GAD-7 scale as an outcome measure of disability in patients with generalised anxiety disorders in. Primary care. Journal of Affective Disorders. 128:277-286.
  • Jordan P, Shedden-Mora M and Lowe B (2017) Psychometric analysis of the Generalized Anxiety Disorder scale (GAD-7) in primary care using modern item response theory. PLoS ONE 12(8):e0182162
  • Lowe B (2008) Validation and standardisation of the Generalised Anxiety Disorder Screener (GAD-7) in the general population. Med Care. 46(3):266-74
  • Zhong QY, Gelaye B and Williams M (2015) Diagnostic Validity of the Generalised Anxiety Disorder - 7 (GAD-7) among pregnant women. PLoS ONE. 10(4):e0125096
  • Heinz A (2017) Psychometric evaluation of the Generalized Anxiety Disorder Screener GAD-7, based on a large German general population sample. Journal of Affective Disorders. 210:338-344.

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