GAD-7 Anxiety Severity Calculator
GAD-7 Anxiety Severity Calculator
Score the seven GAD-7 items out of 21 against Spitzer’s published bands. At the cut-off of 10 the derivation cohort gave 89 per cent sensitivity and 82 per cent specificity — and a positive predictive value near one in five.
GAD-7 total
7 items, 0 to 21Nervous or on edge 2; cannot stop worrying 2; worrying about different things 1; trouble relaxing 1; restlessness 1; irritability 1; afraid something awful might happen 0
Scoring
Range 0 to 21 · bands at 5, 10 and 15 · screening cut-off 10 or more
- 89 and 82, at a cut-off of 10
- Spitzer, Kroenke, Williams and Löwe 2006: 2,740 adults at 15 primary care sites in the United States, 965 of them interviewed by telephone by a mental health professional using the generalised anxiety section of the Structured Clinical Interview for DSM-IV including its six-month duration criterion. A total of 10 or more “optimized sensitivity (89%) and specificity (82%)”
- the specificity is the weak number
- 82 per cent means 18 of every 100 people without the disorder score 10 or more. Against a prevalence of 5 per cent that is 171 false positives for every 44.5 true ones, a positive predictive value of 20.6 per cent. This is the figure a screening page should print and almost never does
- what the bands are for
- severity tracking and treatment-response monitoring. The thresholds at 5, 10 and 15 are a convention over round numbers, not diagnostic categories, and a score is not a diagnosis of generalised anxiety disorder
- a printed error in the source
- Table 2 of the 2006 paper gives the severe band as “5-21” where Table 3 and the text give 15 to 21. The 15 is right. It is recorded here because a reader checking this page against that table deserves to know which of the two is the misprint
Worked example
Nervous or on edge 2; cannot stop worrying 2; worrying about different things 1; trouble relaxing 1; restlessness 1; irritability 1; afraid something awful might happen 0
2 + 2 + 1 + 1 + 1 + 1 + 0 = 8 points
8 sits in the 5-to-9 mild band and below the cut-off of 10
Two more points anywhere crosses that cut-off, and the cut-off is the only boundary on this scale with diagnostic accuracy attached to it
Apply the derivation cohort's 89 per cent sensitivity and 82 per cent specificity at a prevalence of 5 per cent: of 1,000 people, 44.5 true positives against 171 false ones — a positive predictive value of 20.6 per cent
At 15 per cent the same pair gives 46.6 per cent. Four in five positives in the first line, and more than half in the second, do not have the disorder
The published bands, and what is attached to each
| Total | Spitzer 2006 Table 3 label | What is attached to it |
|---|---|---|
| 0 to 4 | Minimal | Nothing beyond the convention |
| 5 to 9 | Mild | Nothing beyond the convention |
| 10 to 14 | Moderate | The cut-off of 10: sensitivity 89 per cent, specificity 82 per cent for generalised anxiety disorder |
| 15 to 21 | Severe | Nothing beyond the convention. Table 2 of the same paper misprints this band as 5 to 21 |
What a GAD-7 of 10 or more is worth, by prevalence
| Prevalence of generalised anxiety disorder | Positive predictive value | Negative predictive value |
|---|---|---|
| 15 in 100 | 46.6 per cent | 97.7 per cent |
| 5 in 100 | 20.6 per cent | 99.3 per cent |
| Sensitivity used | 89 per cent (Spitzer 2006) | |
| Specificity used | 82 per cent (Spitzer 2006) |
Seven items, one derived cut-off, and a specificity that decides everything
The GAD-7 scores seven items from 0 to 3 over the last two weeks and runs from 0 to 21. Spitzer, Kroenke, Williams and Löwe published it in 2006 from 2,740 adults at 15 primary care sites in the United States, with 965 of them interviewed by telephone by a mental health professional using the generalised anxiety section of the Structured Clinical Interview for DSM-IV, including the six-month duration criterion. A total of 10 or more “optimized sensitivity (89%) and specificity (82%)”, and the paper put 5, 10 and 15 forward as the thresholds for mild, moderate and severe anxiety.
The specificity is the number that matters on a public page. Eighty-two per cent means 18 people in every 100 who do not have generalised anxiety disorder will score 10 or more. In a primary care population where perhaps 5 per cent have it, that produces 171 false positives for every 44.5 true ones — a positive predictive value of about 21 per cent. At a prevalence of 15 per cent it rises to about 47 per cent, still below half. Nothing about the instrument changes between those two figures; only who is being screened changes. A total of 10 or more is a reason to look further, and on its own it is more often wrong than right.
What the ordinal total does well is the thing it is least often used for. Repeated in the same person it tracks severity and treatment response, and a fall from 16 to 7 carries information that a single 7 does not. The band labels, by contrast, are a convention over round numbers: only the cut-off of 10 was derived, and the University of Washington’s scoring instructions describe it precisely as “a recommended cutpoint for further evaluation” rather than as a diagnostic threshold. Three of the seven items — restlessness, irritability and trouble relaxing — are also endorsed freely in depression, in chronic pain, in akathisia and in alcohol or benzodiazepine withdrawal, none of which the GAD-7 screens for, so a high total in a patient withdrawing from alcohol is telling you about the withdrawal.
One error in the source, recorded because a reader checking this page against the paper will meet it: Table 2 of the 2006 article prints the severe band as “5-21” where Table 3 and the text give 15 to 21. The 15 is the correct lower bound.
Attribution, as the instrument’s own notice requires. Developed by Drs Robert L. Spitzer, Janet B.W. Williams, Kurt Kroenke and colleagues, with an educational grant from Pfizer Inc. The published form carries “No permission required to reproduce, translate, display or distribute”, and that notice is the reason this page exists while no page here reproduces the AUDIT.
A total on this page is a number, not a diagnosis. These instruments quantify what a person reports, or what an observer records at one moment; a diagnosis rests on a clinical assessment that no questionnaire total stands in for. A low total does not exclude what the instrument screens for. No sensitivity quoted here is 1, every figure was measured in a published cohort rather than in the person in front of you, and someone who endorses nothing may still have the disorder. This page renders no dose, no medication, no treatment regimen and no disposition. It computes the published total and prints the published thresholds with the body that published each one; what follows from the number is a clinical decision this page does not make. Every cut-off, sensitivity, specificity and severity band here is printed with the cohort it was measured in, or with a statement that no source read for this page attaches one — because an instrument’s accuracy is a property of the population it was measured in and not of the instrument. If you are reading this about yourself and you are in distress or thinking about harming yourself, please contact your local emergency number or a crisis line now rather than treating a number as an answer: 999 or Samaritans on 116 123 in the UK and Ireland, 988 in the United States and Canada, or your local emergency service elsewhere.
Frequently asked questions
What is a high GAD-7 score?
The 2006 validation’s Table 3 bands the scale 0 to 4 minimal, 5 to 9 mild, 10 to 14 moderate and 15 to 21 severe. Those are a severity convention. The only derived boundary is the cut-off of 10, which carried 89 per cent sensitivity and 82 per cent specificity for generalised anxiety disorder in the derivation cohort.
How accurate is a GAD-7 of 10 or more?
Sensitivity 89 per cent and specificity 82 per cent in 2,740 primary care adults at 15 US sites, against a structured interview by a mental health professional in 965. Those figures give a positive predictive value of 20.6 per cent at a prevalence of 5 per cent and 46.6 per cent at 15 per cent.
Does a low GAD-7 mean a person is not anxious?
A low total does not exclude what the instrument screens for. No sensitivity quoted here is 1, every figure was measured in a published cohort rather than in the person in front of you, and someone who endorses nothing may still have the disorder. At 89 per cent sensitivity about one in nine people with generalised anxiety disorder scores below the cut-off, and the instrument was validated against generalised anxiety disorder specifically rather than against panic disorder, social anxiety or post-traumatic stress.
Can the GAD-7 be used to diagnose generalised anxiety disorder?
A total on this page is a number, not a diagnosis. These instruments quantify what a person reports, or what an observer records at one moment; a diagnosis rests on a clinical assessment that no questionnaire total stands in for. The instrument was validated against a structured interview that applied the full DSM-IV criteria including the six-month duration requirement, and a two-week questionnaire cannot establish a six-month criterion.
What is the GAD-2?
Items 1 and 2 of this instrument, scored 0 to 6, with a cut-off of 3 or more. At that cut-off it carried 86 per cent sensitivity and 83 per cent specificity for generalised anxiety disorder, and 65 per cent and 88 per cent for any anxiety disorder, in Kroenke and colleagues’ 2007 work.
Related calculators
References
- Patient Health Questionnaire (PHQ-9) and Generalized Anxiety Disorder 7-item scale (GAD-7), the combined published form as distributed by the North Dakota Department of Health and Human Services. Source of every item of both instruments in its exact wording, the four response options and their point values, the shared functional-impairment question, and the developer notice: “Developed by Drs. Robert L. Spitzer, Janet B.W. Williams, Kurt Kroenke and colleagues, with an educational grant from Pfizer Inc. No permission required to reproduce, translate, display or distribute, 1999.”
- Spitzer RL, Kroenke K, Williams JBW, Löwe B. A brief measure for assessing generalized anxiety disorder: the GAD-7. Arch Intern Med. 2006;166(10):1092–1097. Full text read: 2,740 adults at 15 primary care sites in the United States, with 965 interviewed by telephone by a mental health professional using the GAD section of the Structured Clinical Interview for DSM-IV including the six-month duration criterion; a cut-off of 10 or greater “optimized sensitivity (89%) and specificity (82%)”; and the severity bands of Table 3 — 0 to 4 minimal, 5 to 9 mild, 10 to 14 moderate, 15 to 21 severe. Note for a future author: Table 2 of the same paper prints the severe band as “5-21”, which is a misprint against Table 3 and against the paper’s own text.
- Instructions for scoring the GAD-7, University of Washington Department of Psychiatry and Behavioral Sciences. Source of the scoring text: “GAD-7 total score for the seven items ranges from 0 to 21”, “Scores of 5, 10, and 15 represent cutpoints for mild, moderate, and severe anxiety, respectively”, and “When screening for individual or any anxiety disorder, a recommended cutpoint for further evaluation is a score of 10 or greater”.
Not medical advice. For healthcare professionals and education. Reference intervals vary by laboratory and assay — always use your own laboratory's. Never base a dose or a treatment decision on this page alone. Full disclaimer at calcengines.com/disclaimer/