“…Overall, 10 (59%)18 22 23 25–27 29 32–34 of the 17 included studies evaluated the prevalence of sick leave or work absenteeism, while 4 (24%) studies reported the average number of sick leave days (table 1). 22 23 26 34 Absenteeism was obtained from self-constructed questionnaires in eight studies,22 25–27 29 32–34 five were self-administered,25 27 29 32 33 two were face-to-face interviews22 26 and one conducted weekly telephone interviews 34.…”