The most important classification criteria defined by ISCED are typical age of entry into an educational program and theoretical program duration, together forming the cumulative duration of education at the end of the program.
Migraine patients with low socioeconomic status may have a risk of developing medication overuse headache, The duration of education was shorter in migraine patients with low income [43].
The average age of wives at first marriage was 22.0 years old, and the average duration of education was 5.4 years.
Our results make us skeptical in this regard: Even though ISCED offers the tools to distinguish between general and vocational education, for the same duration of education, equal complexity of content is assumed for vocational and general programs, and thus they are assigned to the same main ISCED level.
The head injury severity was classified according to the Head Injury Severity Scale (HISS) Reference category: Stable non-sufferer (absence of headache suffering in both surveys) Abbreviations: OR Odds ratio, CI Confidence interval aAnalyses are adjusted for age, sex, duration of education, daily smoking, CAGE score ≥ 1 and HADS-score.
Subsequently, we also added the following potential confounding factors retrieved from the HUNT2 dataset: duration of education (≤ 9, 10 12 and ≥13 years) as proxy for socioeconomic status, daily smoking (yes/no), total HADS score (categorized from a continuous variable into three categories with score ≤ 16, 17 21 and ≥22) and CAGE score (0 or ≥1).
The HUNT2 and HUNT3 surveys included many health-related items, and in the present study we used the following information about the participants in addition to headache status: age, sex, duration of education, smoking habits, total Hospital Anxiety and Depression Scale (HADS) score, self-reported health, BMI and CAGE score.
Mean duration of education was 8.9±2.2 years.
The mean duration of education in this group was 10.48 ± 2.76 years.
Compared with the women, the men had a significantly higher duration of education and were older.
Duration of education was significantly lower among migraine patients than healthy controls.
