Impact of headache on young people in a school population

Setting

The study was undertaken in three schools in Exeter, UK. Exeter has a population of 119 600, of whom 5800 children are in the target group (aged 12–15 years). The city is of average socioeconomic status, lying on the 48th centile of the England and Wales Index of Multiple Deprivation (IMD). The IMD contains seven domains of deprivation that are available at a small area level and is a proxy for socioeconomic status.16

Statistics

The power calculation was based on a pilot study of 100 pupils in a school that was not used in the survey. It was estimated that for a 95% confidence level to identify a 10% (standard deviation [SD] 2%) population rate of the variable of interest (the percentage of participants that had headache more frequently than once a week), a sample size of 737 participants would be needed.

Measures

The disease-specific measure was the Pediatric Migraine Disability Assessment Score (PedMIDAS). This is a validated instrument that measures the impact of headache-related quality of life in terms of days in the previous 3-month period where headache has had a total or partial impact on school or home life.17 The generic measure was the Pediatric Quality of Life Inventory (PedsQL4), the most widely used generic measure in paediatric practice.18 It has been validated in UK school children,19 and also for use in headache.20

Data collection

Students completed an anonymous questionnaire in school tutorial groups. Questionnaires that were incomplete or that did not conform to the defined marking schema were rejected. It was not possible to follow up the estimated 6% of students who were absent on the day of study. After an initial introduction, students completed questionnaires independently without further assistance to prevent bias in the results.

Summary of main findings

The study demonstrated high levels of headache morbidity. Twenty per cent of the study population reported headache on one or more occasions a week, with an impact on functioning at home or school over 12 days in a 3-month period. Of note, those that had a high impact, defined here as those participants with a headache frequency of two or more times a week (10% of the population), had an impact of headache on 16.8 days in the previous 3-month period and a generic quality of life score lower than that of children with asthma, diabetes, or cancer.

The direction of causality of the relationship described is not known. The current understanding of headache sits within a biopsychosocial framework.22 The interplay between headache, anxiety, depression, somatisation, and quality of life is complex and likely to be bidirectional. Therefore increased frequency of headache may have an impact on lower quality of life or headache may be the result of psychosocial factors, which are a cause of poor quality of life.

Strengths and limitations of the study

There is an emerging consensus that for chronic health conditions both generic and disease-specific health-related quality of life measures should be used when measuring the impact of a condition in paediatric practice.23 This is the first study that compares validated disease-specific and generic measures with frequency of headache in a school population.

The research described headache as a symptom and made no attempt at establishing a diagnosis. Although diagnostic screening questionnaires are available, the difficulties of making headache diagnoses, particularly in children, are well recognised.24 Although a validated instrument was used to measure headache impact, it must be acknowledged that recall may be unreliable when compared with diary measurement. It was not possible to follow up the estimated 6% of students who were absent on the day of study. Some of these absences may have been due to headache, which could underestimate the impact described.

Comparison with existing literature

Two population studies have reported on PedMIDAS. A Turkish study found that 9.7% of a school population had migraine, with an average PedMIDAS score of 9.9 for boys and 11.5 for girls.25 Thirty-two per cent of the children had already been diagnosed with migraine. The current authors have previously described a high-impact group of 3% of a primary care practice population with an average PedMIDAS score of 23.4.26

There have been no adequately powered studies describing the generic impact on quality of life of children. One small study of 31 children using the Short Form-36 found significant reductions across six of the eight domains. A study in a specialist paediatric headache centre found an average PedsQL4 score of 72.27

Implications for clinical practice

This study has identified a reduced quality of life and impact of functioning in headache sufferers in a school population. Other childhood problems such as asthma and diabetes have both a lower prevalence and a lower impact on quality of life than headache, yet receive considerable attention. The needs of many children with headache may be unmet.26

In an adult population, headache sufferers do not consult their doctors, patients may not receive the correct diagnosis, and even when a correct diagnosis is made, effective treatment may not be given.28 These problems are likely to be more prominent in a paediatric population, where individuals are less able to articulate their problems and seek attention. GPs are well placed to identify and manage this unmet need.