p (1-p) (1) Inside: (p) 2 n: is the sample size 36 Z2 1-/2 Is a reliability coefficient, taking a value of 1, 96 (with a reliability of 95%), p = 0, 04; Community prevalence rates of previous studies The greatest variance of the study compared with the actual, = 0, 2 Thus (p = 0, 04, = 0, 2) instead of (1) we have: n = 2.304 As the commune has over 5.000 adults / 1 commune.