Amanda Watson, Anna Timperio, Helen Brown, Kylie D Hesketh
Process evaluation of a classroom active break (ACTI-BREAK) program for improving academic-related and physical activity outcomes for students in years 3 and 4
BMC public health
rose g department epidemiology london school hygiene tropical medicine keppel street london wc1e 7ht uk sick individuals sick populations international journal epidemiology 1985143238 aetiology confronts two distinct issues determinants individual cases determinants incidence rate exposure necessary agent homogeneous within population casecontrol cohort methods fail detect identify markers susceptibility corresponding strategies control highrisk approach seeks protect susceptible individuals population approach seeks control causes incidence two approaches usually competition prior concern always discover control causes incidence