THE HENRY-FORD-HOSPITAL HEADACHE-DISABILITY-INVENTORY (HDI)

To quantify the impact of headache on daily living, we developed a 25- item headache disability inventory (HDI). The alpha version of the HDI (alpha-HDI) consisted of 40 items, each requiring a ''yes'' (four poi nts), ''sometimes'' (two points), or ''no'' (zero points) response bas ed on items derived empirically from case history responses of subject s with headache. From the alpha-HDI, we derived a 25-item beta version (beta-HDI) with the items subgrouped into functional and emotional su bscales. The internal consistency/reliability was strong, as was const ruct validity. The test-retest reliability for the beta-HDI was accept able for the total score and functional and emotional subscale scores. A 29-point change (95% confidence interval) or greater in the total s core from test-retest must occur before the changes can be attributed to treatment effects. The HDI is useful in assessing the impact of hea dache, and its treatment, on daily living.