Table 1 Description of the 16 candidate variables
Candidate variable | Formation from baseline questionnaire | |
|---|---|---|
Headache characteristics | ||
Intensity of headache | Numerical rating scale (NRS) from 0 to 10 | |
Frequency of headache | Number of days with headache per week. 1–2 days/3–5 day/nearly every day | |
Duration of headache | 0.5–1 year/1–3 years/more than 3 years | |
Length of episodes | < 2 h/half day/whole day/day and night | |
Absence from school | 0/1–5/5–20/ > 20 days last year | |
Co-occurring symptoms | Summary index based on four binary items: nausea, vomiting, light sensitivity, and sound sensitivity | |
Migraine-tension-type | Continuous index based on severity and co-occurring symptoms (high values indicating migraine, low values tension type headache). Derived from previous analyses of the same cohort [17] | |
Variables identified from the literature | Relationship with headache | |
Age | Reported age in years | Headache prevalence rises with age and there is a significant increase in headache prevalence after age 12 [18, 19] |
Sport activity | "0 times”,”1–3 times", or " > 3 times" | Low physical activity is associated with recurrent headaches in adolescents [20,21,22] |
Screen time | “low”, “normal”, or “high” based on age-specific cut points for the self-reported screen time | A forward head posture, as often assumed in front of computers, has been associated with neck and shoulder pain [5, 23] |
Sleep duration | “low”, “normal”, or “high” based on age-specific cut points for the self-reported sleep duration | Poor quality of sleep is associated with headache in children [24,25,26] and this association is particularly evident in migraine [24]. Children with headache report more daytime symptoms of sleep disturbances, including fatigue, tiredness, and sleepiness [27]. Furthermore, excessive screen time may influence headache mediated by less sleep, and reduced sleep duration can be an indicator of an unhealthy lifestyle [28] |
Trauma experience | Summary index based on three items on lifetime trauma experience (no need for treatment, need for treatment, hospitalization) | The cervical spine is the most commonly injured region of the spine in young children [29, 30] and thus cervicogenic headache might be a consequence of cervical dysfunction |
History of concussion | Binary item on lifetime experience of concussions | In adults, headache associated with head injury is estimated to persist for 12 to 24 months after the injury in 20–30% [31] |
History of neck pain | Report of neck pain within the past year | The cervical spine is the most commonly injured region of the spine in young children [29, 30] and thus cervicogenic headache might be a consequence of cervical dysfunction |
Socioeconomic status | Income is here considered as a proxy for socioeconomic status: self-reported annual income in 8 categories (labelled in 1000 €) | Socioeconomically disadvantaged children are more prone to headache [32] |
Headache in the family | Presence of headache in the parents: “none”, “one parent “, or “both parents” | A history of headache in a first-degree family member has been reported in up to 72% of children with headache with a predominance of maternal headache[19, 25, 33, 34] |