GAD-7

Owned by Paul Macey (admin)
Last updated: Nov 25, 2019
2 min read

Summary

GAD - generalized anxiety disorder; GAD measures anxiety symptoms, and is used as screening tool

Max score: 21

Cutoff: 8 (inclusive)

Ranges: 5 mild, 10 moderate, 15 severe (inclusive)

Cutoffs inclusive.

Details

The GAD-7 score is calculated by assigning scores of 0, 1, 2, and 3, to the response categories of 'not at all', 'several days', 'more than half the days', and 'nearly every day', respectively, and adding together the scores for the seven questions.

Scores of 5, 10, and 15 are traditionally taken as the cut-off points for mild, moderate and severe anxiety, respectively. When used as a screening tool, further evaluation is recommended when the score is 8 or greater; this was changed from 10 originally - see below.


Using the threshold score of 10, the GAD-7 has a sensitivity of 89% and a specificity of 82% for GAD. It is moderately good at screening three other common anxiety disorders - panic disorder (sensitivity 74%, specificity 81%), social anxiety disorder (sensitivity 72%, specificity 80%) and post-traumatic stress disorder (sensitivity 66%, specificity 81%).[3]

However, a meta analysis in 2016 showed a cutoff of 8 had suitable sensitivity and specificity for GAD. ( [sensitivity: 0.83 (95% CI 0.71-0.91), specificity: 0.84 (95% CI 0.70-0.92)] although cutoff scores 7-10 also had similar pooled estimates of sensitivity/specificity)[4].


From : https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5093940/


GAD-7 is scored by a frequency scale from 0 to 3 for each item and is also most commonly totalled to give a score between 0 and 21. It was validated against other health measures and against an MHP interview. A clinical cut-off of 10 was identified against the MHP interview diagnosing generalised anxiety disorder (GAD) with a sensitivity of 89 % and a specificity of 82 % [2]. However, a later study [25] evaluated GAD-7 as a broader instrument to test for any anxiety disorder and determined an acceptable AUC of 0.86. From this AUC, a lower cut-off of 8 for any anxiety disorder was recommended, which gave a sensitivity of 77 %, a specificity of 82 % and a positive likelihood ratio of 4.4. This lower cut-off was the one adopted by IAPT to sit alongside that for the PHQ-9 ([3] p22).


The GAD-7 originates from Spitzer RL, Kroenke K, Williams JB, et al; A brief measure for assessing generalized anxiety disorder: the GAD-7. Arch Intern Med. 2006 May 22;166(10):1092-7. GAD-7 © Pfizer Inc. all rights reserved; used with permission.

Further reading & references

  1. Swinson RP; The GAD-7 scale was accurate for diagnosing generalised anxiety disorder. Evid Based Med. 2006 Dec;11(6):184.
  2. Spitzer RL, Kroenke K, Williams JB, et al; A brief measure for assessing generalized anxiety disorder: the GAD-7. Arch Intern Med. 2006 May 22;166(10):1092-7.
  3. Kroenke K, Spitzer RL, Williams JB, et al; Anxiety disorders in primary care: prevalence, impairment, comorbidity, and detection. Ann Intern Med. 2007 Mar 6;146(5):317-25.

  4.  Plummer 2016 Screening for anxiety disorders with the GAD-7 and GAD-2: a systematic review and diagnostic metaanalysis