Devising and validating a headache diary in a series of patients with chronic daily headache from Colombia

objective: to devise and test the reliability and validity of a brief headache diary in a series of colombian patients with chronic daily headache. methods: the study was designed in five stages: selection of domains (group of patients and experts); initial devising of the items (writing group); identification of non-understandable items (n=20); assessment of internal consistency (n=100); assessment of validity and assessment of sensitivity to change during seven consecutive days (n=25, 175 observations). results: five domains were selected: headache presence, severity and length of pain, analgesics intake, and missing workdays. the headache diary is internally consistent (≈75% of rotated variance), correlates with the medical interview (spearman's rho and kendall's tau over 0.8 for each domain) and it has an adequate and stable sensitivity and specificity (82 to 96%). conclusions: this headache diary is a reliable and valid instrument and represents the most important features affecting colombian patients with chronic daily headache.