Short communication: Persistent socio-economic inequality in frequent headache among Danish adolescents from 1991 to 2014.

BACKGROUND: The association between socio-economic status (SES) and headache among adolescents is an understudied issue, and no study has examined whether such an association changes over time. The aim was to examine trends in socio-economic inequality in frequent headache among 11- to 15-year-olds in Denmark from 1991 to 2014, using occupational social class (OSC) as indicator of SES. METHODS: The study applies data from the Danish part of the international Health Behaviour in School-aged Children (HBSC) study. HBSC includes nationally representative samples of 11-, 13- and 15-year-olds. This study combines data from seven data survey years from 1991 to 2014, participation rate 88.6%, n = 31,102. We report absolute inequality as per cent difference in frequent headache between high and low OSC and relative inequality as odds ratio for frequent headache by OSC. RESULTS: In the entire study population, 10.4% reported frequent headache. There was a significant increase in frequent headache from 8.0% in 1991 to 12.9% in 2014, test for trend, p < 0.0001. This increasing trend was significant in all OSCs. The prevalence of frequent headache was significantly higher in low than high OSC, OR = 1.50 (95% CI: 1.34-1.67). This socio-economic inequality in frequent headache was persistent from 1991 to 2014. CONCLUSION: There was a significant and persistent socio-economic inequality, i.e. increasing prevalence of frequent headache with decreasing OSC. The association between socio-economic position and headache did not significantly change over time, i.e. the statistical interaction between OSC and survey year was insignificant. SIGNIFICANCE: The prevalence of frequent headache among adolescents increases with decreasing SES. This socio-economic inequality has been persistent among adolescents in Denmark from 1991 to 2014. Clinicians should be aware of this social inequality.

Discussion groups with parents of children with cerebral palsy in Europe designed to assist development of a relevant measure of environment.

BACKGROUND: An instrument to measure environmental factors relevant to physically impaired children is being developed in a European context. Preliminary work in England had identified some potentially important themes. Further inquiry was needed to identify issues important in other European countries. OBJECTIVE: To inform the content of a questionnaire relevant to the environment of children with cerebral palsy (CP) living in Europe. DESIGN: A qualitative study using discussion groups. PARTICIPANTS: Parents of 28 children with CP from five countries; Denmark, France, Italy, Ireland and Sweden. One discussion group was held in each country with an average of seven parents per group. RESULTS: The four themes identified in the preliminary work done in England were strongly confirmed across Europe - namely: Mobility, Transport, Support by and to parents, and Attitudes of individuals and institutions towards children. Two new themes identified in the discussion groups were Bureaucracy and Access to information about rights and entitlements. CONCLUSIONS: The environmental factors that cause concern to parents of children with CP are similar across Europe. A prototype environmental questionnaire has been developed based on these findings. The environmental questionnaire is in use in a study in nine European centres.

The Danish Cerebral Palsy Registry. A registry on a specific impairment.

Cerebral palsy (CP) is the commonest disabling impairment in childhood, with a prevalence of 2-3 per 1000 live births. The Danish Cerebral Palsy Registry is a research registry that contains cases of CP from birth year 1925 and has estimated the birth prevalence since 1950. Data on children with CP are collected from paediatric departments and one special institution for disabled children. The children are included by a child neurologist and an obstetrician, and information on pregnancy, birth, neonatal period, impairments and demographic data on the child and mother are registered in a standard form. The uptake area is eastern Denmark, covering about 50% of the population, but the rest of Denmark is planned to be included from 2001. The Registry is large, well established and validated, and the definitions and collection procedures have not changed through several decades. It therefore has great research potential. Birth prevalence is estimated continuously, and changes over time are analysed and correlated with pre- and perinatal conditions. A correlation between increased survival of preterm babies and an increased prevalence was found previously, and a decreased prevalence in very preterm infants was later associated with less use of mechanical ventilation. A study correlating CP and maternal infection is ongoing. Collaboration between 14 European CP registries allows the true differences in prevalence between different countries to be studied. Linkage to other individually based registries in Denmark will allow the social consequences of CP to be described.