We conducted a cross-sectional study with a school-based sample whereby a questionnaire was distributed to primary and middle schoolchildren aged 7-16 years in governmental schools in Kuwait. Equal boys and girls schools were randomly selected from two major governorates in Kuwait; Al-Farwaniyah, the most densely populated with a total of 50263 students and farther away from the center of the State of Kuwait, and Hawally, which is more urbanized and central in location with a total of 30909 students in primary and middle schools. These two governorates were chosen to cover the geographic diversity of Kuwait.
Population of Interest
Study population included Kuwaitis schoolchildren aged 7-16 years.
Sample Size
According to the information from Kuwait Ministry of education in academic year 2018/2019, the number of Kuwait students in primary and middle schools is 231927. Of those, 126542 (54.56%) are girls and 105385 (43.44%) are boys. Hence, the sample size was calculated and determined to be 950 using a special formula based on reported prevalence of headache from previous national and international epidemiological studies, which is around 54.4% and of migraine, 9.1% [13-14]. Then, the sample was increased by 20% to overcome the problem of non-response and missing data. Five hundred complete questionnaires were obtained from Al-Farwaniyah governorate, number of population is 230,573. \Number of population in Hawally governorate is 221553 and 591 complete questionnaires were obtained from Hawally schools. Kuwait population is complex in its infrastructure. Each governorate predominates in terms of the peoples’ cultures, nationality, and backgrounds. For example, one governorate may predominate with bedouin Kuwaities or ‘nomads’ who are distinct from their fellow urbanized Kuwaities even in terms of diseases as it is considered to be a fact that most bedouins engage in consanguineous marriages (e.g first degree cousins) which can produce genetic and other forms of diseases not found in those who do not have inter-familial marriages. Since governmental schools are purely comprised of Kuwaiti students, we could not rely solely on Farwaniyah governorate as it is the biggest amongst the rest, instead, Hawalli was needed to nullify that form of selection bias. We clarified and highlighted this in red color in the manuscript.
Survey and Sampling
Representative random sample of school classes was selected, stratified by grade (3rd, 5th, 7th, 9th), and school type (school for boys and schools for girls). So, the final selection of schools and school classes that were idensified for this study covered age spectrum from childhood through adolescence and reflected Kuwaiti students of schools appropiately. All children and adolescents within these selected classes were included, except for those who refused to participate, were non-Kuwaiti nationals, has history of medical or neurological disease or were absent on the day of the survey. Of 1485 questionnaires that were distributed, 1089 students completed the questionnaire with a respondent rate of 73.4% . Kuwaiti governmental schools are free of charge and thereby only recruit Kuwaiti students. This is purely based on the Kuwaiti regime. Since governmental schools are unified in nearly all aspects, we could not resort to privately owned schools which operate with vast diversity from one another. We clarified and highlighted this in red color in the manuscript. Figure 1 displays the flow chart.
Study Tools
The survey used Lifting the Burden, Headache-Attributed Restriction, Disability, Social Handicap and Impaired Participation (HARDSHIP) questionnaire that was translated into Arabic [15]. The Child HARDSHIP for children aged 6–11 years and Adolescent HARDSHIP questionnaire for adolescents aged 12– 17 years were used in this study. The HARDSHIP questionnaire has already demonstrated validity and acceptability in multiple languages and cultures including the Arabic Language. This questionnaire questions including sociodemographic, screening and diagnostic questions and enquiries into burden in various domains and quality of life. The last part of the questionnaire included questions on the use of healthcare system in the past, medication use, and Headache-Attributed Lost Time Index questionnaire. Burden questions referred to the numbers of days missed from school, leaving school early or with impaired everyday activities due to headache, within the previous four weeks. Data were obtained from the children and adolescents themselves after explanation of the questions by physician of the study team. Prior to presenting the questionnaires, a brief explanation was made to clarify the objectives in simple terms as the population in Kuwait is slightly weary prior to conducting any questionnaire and may, more commonly than not, refuse the questionnaire if they felt it were to be to intrusive. When they reach a proper level of understanding we tend to have a good turnover rate. They were told about the confidentiality of their answers and their importance and that human subjects were not to be utilized for the purpose of the study. The students received the questionnaires and discussed it with their parents and on the second day one of the investigator team sit with the student to fill in the questionnaire. Questionnaire distribution and data collection were organized and conducted by physician supervisors during a school class as a paper-pencil version. To collect study data, well trained physicians conducted face to face interviews using Child and Adolescent HARDSHIP questionnaires
Diagnosis of headache
Diagnoses were performed by HARDSHIP algorithm) applying ICHD-3 beta criteria [16-17]. Following the section on personal details and demographic data, a question was introduced: “In the last year, have you had a headache that was not part of another illness?” Participants who responded with “no” were classified as headache-free; those who responded with “yes” were asked whether their headache episodes were of one or more types. If the child reported more than one type of headache, subsequent questions targeted the most bothersome headache type. For diagnose of headache type, we asked questions about headache frequency and duration, headache characteristics, associated symptoms and use of acute medication. We separated those reporting headache days for 15 or more, and diagnosed propable medication over use headache (pMOH) when acute medication was used on 10 or more days/ month. For headaches on less than 15 days/month we applied diagnostic criteria, in order, for definite migraine, definite tension type headache (TTH), probable migraine and probable TTH. Participants with headache who fell into none of these categories were categorized as “unclassifiable headache”. In the analysis, definite migraine and probable migraine were grouped as migraine, and definite TTH and probable TTH as TTH.
Quality Assurance and Validity
The team leader reliably stored all completed questionnaires at the end of each day. Errors were corrected by discussing them with the interviewer and a revisit was arranged if discrepancies could not be corrected. The team leader monitored and assisted researchers on a regular basis to resolve any problems and to review the completed questionnaires.
Duration of the Project
The fieldwork was carried out over a period of 3 months from 1/10/2018 till 1/1/2019.
Ethics
Ministry of health and ministry of Education in Kuwait approved the study. Participants was given a simple explanation about the aim of the study being considered an ethical issue. Written informed consent was obtained from all participants and their parents before the questionnaire was distributed. The participants were granted the right to decline participation at any time during data collection. All data were protected in accordance with the ethical guidelines of the Council for International Organizations of Medical Sciences and the principles in the Declaration of Helsinki [18-19].
Data Analysis
We used IBM SPSS Statistics 20.0. Completed questionnaire data and double check of all data was made, with inconsistencies reconciled by reference to the original documents. Error rate of 1.9 % was identified. One year prevalence for primary headache disorders as percentages with 95% CIs. Adjusted prevalence for gender and school stage according to the participation of the Kuwaiti students was reported. Duration of headache was recorded as continuous data in hours. Headache frequency was recorded in days over the preceding 3 months, and typical headache intensity on a verbal rating scale (“not bad,” “quite bad,” and “very bad”). We used proportions, 95% CIs, means, and SDs to summarize the distributions of variables and chi-square, for significance of differences. P < 0.05 was considered as statistically significant.