GAD-2 Anxiety Screen Calculator
GAD-2 Anxiety Screen Calculator
Score the two GAD-2 items out of 6 against the cut-off of 3. The published figures differ for generalised anxiety disorder and for any anxiety disorder, and both sets are worked through a 2 × 2 here.
GAD-2 total
2 items, 0 to 6Nervous or on edge: more than half the days (2). Cannot stop or control worrying: several days (1)
Scoring
Range 0 to 6 · preferred cut-off 3 or more
- 86 and 83, or 65 and 88
- the first pair is for generalised anxiety disorder and the second for any anxiety disorder, both at a cut-off of 3 or more, from Kroenke and colleagues’ 2007 Annals of Internal Medicine study. Widening the target condition costs twenty-one points of sensitivity and buys five of specificity, exactly as it does on the PHQ-2
- the predictive value in primary care
- 21.0 per cent at a 5 per cent prevalence of generalised anxiety disorder and 47.2 per cent at 15 per cent, computed from the 86 and 83 pair. Four in five positives in the first line do not have the disorder, and the instrument cannot say which four
- a pre-screen, not a short version
- the GAD-2 is designed as a first stage that decides whether to ask the remaining five GAD-7 items. It carries no severity bands of its own, and a total of 6 is not a severe-anxiety finding — it is a positive pre-screen
- what the cohort could not establish
- the figures above come from the published report rather than from a cohort description this page could read in full: the source read for them gives the operating characteristics and the citation but not the sample size or the setting, and that gap is stated rather than filled
Worked example
Nervous or on edge: more than half the days (2). Cannot stop or control worrying: several days (1)
2 + 1 = 3 points, which reaches the preferred cut-off of 3 or more
Apply 86 per cent sensitivity and 83 per cent specificity at a 5 per cent prevalence of generalised anxiety disorder: of 1,000 people, 43 true positives against 161.5 false ones — a positive predictive value of 21.0 per cent
At 15 per cent the same pair gives 47.2 per cent
Switch target condition to any anxiety disorder, where the pair is 65 and 88: at a 20 per cent prevalence the positive predictive value is 57.5 per cent and at 8 per cent it is 32.0 per cent
Four numbers from two instruments' worth of published figures, and not one of them is a diagnosis
The same cut-off against two target conditions
| Target condition | Sensitivity | Specificity |
|---|---|---|
| Generalised anxiety disorder | 86 per cent | 83 per cent |
| Any anxiety disorder | 65 per cent | 88 per cent |
Positive predictive value at four prevalences
| Target and prevalence | Positive predictive value | Negative predictive value |
|---|---|---|
| Generalised anxiety disorder, 15 in 100 | 47.2 per cent | 97.1 per cent |
| Generalised anxiety disorder, 5 in 100 | 21.0 per cent | 99.1 per cent |
| Any anxiety disorder, 20 in 100 | 57.5 per cent | 91.0 per cent |
| Any anxiety disorder, 8 in 100 | 32.0 per cent | 96.7 per cent |
A two-item pre-screen, and four honest numbers
The GAD-2 is the first two items of the GAD-7 — feeling nervous, anxious or on edge, and not being able to stop or control worrying — scored 0 to 3 each over the last two weeks for a total of 0 to 6. The preferred cut-off is 3 or more. The operating characteristics come from Kroenke, Spitzer, Williams, Monahan and Löwe’s 2007 study in the Annals of Internal Medicine: 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.
The two pairs are the content of this page. They are the same two questions, asked of the same people, at the same cut-off, and they answer different questions: widening the target condition from generalised anxiety disorder to any anxiety disorder costs twenty-one points of sensitivity and buys five of specificity. The PHQ-2 does exactly the same thing with depression, which suggests the pattern is a property of short screens rather than of anxiety. A figure quoted without its target condition tells a reader nothing they can use.
Work either pair through a two-by-two table and the result is sobering in a useful way. On the 86 and 83 pair, at a 5 per cent prevalence of generalised anxiety disorder, a positive GAD-2 carries a positive predictive value of 21 per cent; at 15 per cent it carries 47 per cent. On the 65 and 88 pair for any anxiety disorder, the figures are 32 per cent at 8 per cent prevalence and 58 per cent at 20 per cent. All four are below 60 per cent. That is not a criticism: a pre-screen exists to decide whether to ask more questions, and its job is to miss almost nobody rather than to be right about everybody.
What a positive total means in practice, then, is that the remaining five GAD-7 items are worth asking. The GAD-2 has no severity bands of its own, and a total of 6 is a positive pre-screen rather than a severe-anxiety finding. One gap is worth stating rather than filling: the source read for the operating characteristics gives the pairs and the citation but not the sample size or the setting of the 2007 cohort, so this page names the study and does not describe a cohort it could not read.
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 positive GAD-2 score?
Three or more out of six. At that cut-off the published figures are 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.
Is the GAD-2 a short version of the GAD-7?
It is the first two items of it, and it does a different job. The GAD-7 bands severity at 5, 10 and 15; the GAD-2 has no severity bands at all and exists to decide whether to ask the other five items. A GAD-2 of 6 is a positive pre-screen, not a severe-anxiety finding.
Does a GAD-2 below 3 mean someone 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 65 per cent sensitivity for any anxiety disorder, roughly a third of those cases score below the cut-off. 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.
How much is a positive GAD-2 worth in primary care?
On the 86 and 83 pair, a positive carries a positive predictive value of 21.0 per cent at a 5 per cent prevalence of generalised anxiety disorder and 47.2 per cent at 15 per cent. Both are below half, and neither figure involves any change to the instrument.
Can the GAD-2 be scored alongside the PHQ-2?
They are routinely administered together as a four-item pre-screen, but their totals must not be added. Each has its own cut-off of 3 or more on its own 0-to-6 scale, and a combined total out of 12 has no published meaning, no cut-off and no validation.
Related calculators
References
- Generalized Anxiety Disorder 2-item scale (GAD-2), National HIV Curriculum, University of Washington. Source of the two items, the response values, the cut-off (“A score of 3 points is the preferred cut-off for identifying possible cases”), the operating characteristics at that cut-off — 86 per cent sensitivity and 83 per cent specificity for generalised anxiety disorder, 65 per cent and 88 per cent for any anxiety disorder — attributed to Kroenke K, Spitzer RL, Williams JB, Monahan PO, Löwe B. Anxiety disorders in primary care: prevalence, impairment, comorbidity, and detection. Ann Intern Med. 2007;146(5):317–325. Also carries the developer notice “No permission required to reproduce, translate, display or distribute”.
- 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.
- 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.”
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/