They have a hard time categorising it".
The first part of the book, therefore, spends an inordinate amount of time categorising different kinds of anti-Semites and anti-Semitisms (I counted 22 sub-categories in Chapter One).
Workforce participation was based on an item assessing employment status, with 'unemployed' and 'not in the labour force' categorised as non-participation and employed 'full-time' or 'part-time' categorised as participation.
First, using a similar method reported in other studies [ 6, 7] occupational sitting time was categorised into tertiles of low (<360 minutes/day) moderate (360-420 minutes/dand, and high sitting time (421-840 minutes/day).
Self-reported time in bed, awakening time and bedtime were assessed for each adolescent by asking, "What time did you usually go to bed and wake-up last week?" The responses for awakening time were categorised as ≤5:00, 6 00, 7 00, 8 00 and ≥9 00 and the responses for bedtime were categorised as ≤21 00, 22 00, 23:00, 24:00, 1 00 and ≥2 00; numbers represent the military time of day.
In Northern Ireland, the majority of family holidays taken during term time are categorised as an unauthorised absence.
Alcohol consumption was determined as frequency of drinking alcohol per time unit, categorised into none or ≤1 time/month, 2 4 times/month or ≥2 times/week.
Asbestos exposure was further assessed by frequency of exposure, defined as the percentage of working time exposed (categorised as 1 5, 5 30 or >30%), and intensity of exposure (categorised as low, medium or high).
When cumulative length of use and call time were categorised into quartiles according to distribution among the controls for each tumour type, as shown in Table 2, no increasing trend was found in risks of glioma, meningioma, or pituitary adenoma.
