Grading of headache intensity. A proposal

Current severity (intensity) grading in headache is based upon a 4-grade category scale that includes the zero grade. For ordinary scientific and practical work, a low-sensitivity scale may suffice. However, in given instances, such grading may be insufficient; one might for instance need to know more exactly where the healthy state ends and where headache starts. This may in particular concern epidemiological studies and mass screening. The placement of the “divisory bar” will naturally have a clear impact on the prevalence of headaches, especially the mild ones such as tension-type headache. A 7-step scale is proposed with “excruciating headache” at the top (e.g. cluster headache and chronic paroxysmal hemicrania). Below the mild category of the IHS scale, two categories have been proposed: I, minimal unpleasantness, without any reduction of thriving and without procrastination; and II, discomfort/heaviness with reduction of thriving and procrastination. The bar for discriminating between the healthy state and a headache disorder with an impact upon social life should probably be put between categories I and II on the scale. In situations where increased sensitivity of intensity grading is desirable, such a scale may be useful. This scale has been extensively used during the Vågå study of headache epidemiology, where it has been easy to apply. Consistency tests showed acceptable reproducibility values.