Table 1 Headache diagnoses by available data according to the International Classification of Headache Disorders (ICHD)
ICHD classification criteria | Available data |
|---|---|
Migraine | |
A. At least five attacks fulfilling criteria B–D | Since all the children had weekly headaches, we assumed the criterion of five attacks to be fulfilled for everybody |
B. Headache attacks lasting 2–72 h | Our data contains one corresponding item with the answer options: “Less than 2 h”, “2 h up to half a day”, “The whole day”, “All day and all night”. If one of the three latter was chosen, we considered the criterion to be fulfilled |
C. Headache has at least two of the following four characteristics: | Headache has at least two of the following three available characteristics: |
1. Unilateral location | The variable “location” did not directly include a distinction between unilateral and bilateral location. Migraine in children under 18 years are often bilateral. However, we chose to explore if the definition for adults was suitable for children and therefore regarded the criterion as fulfilled, if the answer option “one side of the head” or “behind one eye” was chosen |
2. Pulsating quality | Unfortunately, we did not have a variable on the quality of the headache. Hence, this criterion was ignored |
3. Moderate to severe pain intensity | The children rated their pain intensity on the numerical rating scale from 0 to 10. This was then categorized into mild (0–4), moderate (5–6) and severe pain (7–10) |
4. Aggravation by or causing avoidance of routine physical activity (e.g. walking or climbing stairs) | The only relevant variable for this criterion was “Aggravated by sports”. The criterion was assumed to be fulfilled if the answer was “yes” |
D. During headache at least one of the following: | |
1. Nausea and/or vomiting | Corresponding items were available and used |
2. Photophobia and phonophobia | Corresponding items were available and used |
Frequent episodic tension-type headache | |
A. At least 10 episodes of headache occurring 1–14 days/month on average for > 3 months (≥ 12 and < 180 days/year) and fulfilling criteria B–D | The children were having weekly headaches hence we assumed this criterion to be fulfilled |
B. Lasting from 30 min to seven days | The response options for the question on the duration distinguished only between ‘less than 2 h’ and ‘above 2 h’. Hence, less than 30 min was not an option, and this criterion was ignored |
C. At least two of the following four characteristics: | Headache has at least two of the following three available characteristics: |
1. Bilateral location | We did not have a location named ‘bilateral’, but we regarded the criterion as fulfilled if the answer option named ‘the whole head’ was used |
2. Pressing or tightening (non-pulsating) quality | Unfortunately, we did not have a variable on the quality of the headache. Hence this criterion was ignored |
3. Mild or moderate intensity | The children rated their pain intensity on the numerical rating scale from 0 to 10. This was then categorized into mild (0–4), moderate (5–6) and severe pain (7–10) |
4. Not aggravated by routine physical activity such as walking or climbing stairs | The criterion was assumed to be fulfilled if the answer to “Aggravated by sports” was “no” |
D. Both of the following: | |
1. No nausea or vomiting | Corresponding items were available and used |
2. No more than one of photophobia or phonophobia | Corresponding items were available and used |