Skip to main content

Table 2 Overall change in 30-day substance use (prevalence) before and six months after treatment (N = 497)

From: Therapeutic community drug treatment success in Peru: a follow-up outcome study

Type of Substance use Before Treatment 6 months after Treatment Difference3 Effect Size4
  Self reported1 Self or Family reported2 Self reported1 Self or Family reported2 Self reported1 Self or Family reported2 Self reported1 Self or Family reported2
Illegal Drug use 90% 91% 34% 43% 56%*** 49%*** 1.12 (Large) .98 (Large)
PCB (Coca Paste) use 62% 67% 22% 33% 40%*** 35%*** .82 (Large) .72 (Medium)
Cocaine use 30% 39% 8% 20% 22%*** 19%*** .52 (Medium) .48 (Medium)
Cannabis use 37% 45% 13% 24% 24%*** 21%*** .53 (Medium) .49 (Medium)
Alcohol use to intoxication 68% 72% 33% 42% 35%*** 31%*** .67 (Medium) .62 (Medium)
  1. Note: *p ≤ .05, **p ≤ .01, ***p ≤ .001; 1 Includes Self reported relapse (n = 497); 2 Self or Family indicated relapse (n = 573); 3Standard deviations may be calculated from percentages using the binomial approximation to the variance, where SD = (p(1 – p))2; 4Effect Size: Proportions converted to Cohen d statistic with a small effect size equals .20, a medium effect size equals .50, and a large effect size equals .80[73]
\