Construction of a migraine-tension-type-index
nausea/vomiting, headaches, phonophobia, headache, migraine, tension-type-headache, photophobia, nausea, vomiting
MIGRAINE, TENSION-TYPE HEADACHE, TENSION TYPE HEADACHE
Instead of applying an existing categorization, it is possible to use our data to investigate whether the distinction between migraine and tension-type headache also makes sense in children, and to explore whether our data can suggest a more diverse way to categorize headaches than the traditional categorization. If there is evidence for this, it might be possible to develop an index helping to identify those children who can be assigned definitely to one type and to evaluate the degree of either migraine or tension type headache in children with mixed headaches.According to the ICHD, migraine and tension-type-headache differ with respect to severity, co-occurring symptoms (nausea/vomiting, photophobia and phonophobia), relation to routine physical activity, and location. As pointed out above, closely corresponding information was available in our data. Consequently, we explored the correlation among these variables to check, whether corresponding dimensions were identifiable and tried to combine the emerging dimensions into one index. We approached this step by inspection of association measures (Pearson correlation, Odds ratios) for each pair of variables. We used a factor analysis with varimax rotation to identify latent variables/dimensions. To summarize the information from several variables into one index, the first principal component score was used. In this score, the weights of each variable are chosen in the way maximizing the variance of the resulting score.The following variables were included in this analysis:Aspects of severity: Intensity, frequency, length of headache episode, duration of headache prior to entering the project, the use of medicine and number of days absent from school.Co-occurring symptoms: nausea, vomiting, phonophobia, photophobiaAggravation: Physical activityLocation of headache