Study
Killias and colleagues (2010) used a randomized controlled trial to evaluate the impact of the Canton of Vaud (CV) community supervision program. The implementation of the CV program was evaluated to determine whether inmates assigned to participate in the program had lower rates of reconviction compared with those assigned to short custodial sentences.
Following notification of their eligibility for the program, inmates who contacted the Swiss Correctional Service were interviewed. If found suitable according to certain criteria (such as aptitude, absence risks, sufficient motivation), they were informed about the community service options available and random assignment procedures. All interested parties were required to fill out a primary questionnaire.
During the interview process, participants were randomly assigned to community service (treatment group) or to prison (control group) by random numbers; the odds were 5 to 2 (community service versus prison, respectively) according to the expected demand and available resources. Prior to random assignment, some participants were purposely selected for community service rather than prison by the officer in charge of the program. This group was limited to 25 percent (36 participants) of all eligible participants to reduce resistance to random selection and to eliminate manipulation of the selection process. Those in the community service group were assigned to many different jobs, while those randomly assigned to short custodial sentences were usually incarcerated full time and therefore had a homogenous experience.
Originally, from 1993 to 1995, 141 defendants agreed to participate in the CV program and be sentenced to short-term imprisonment (no longer than 14 days). Of this group, 100 were randomly assigned to community service and 41 to prison. As a result of the loss of some study participants, the final sample included 36 participants who were purposely selected for the community service group (and were analyzed separately to protect the study’s internal validity), 80 participants who were randomly assigned to the community service group (treatment group), and 38 participants who were randomly assigned to short-term incarceration in prison (control group).
More than 2 years after they performed community service or served a short custodial sentence, 159 participants were contacted and asked to fill out a questionnaire on their current life and work circumstances. Those who returned the anonymous questionnaire were offered a check for 20 Swiss francs (approximately $14 US). Not all participants completed the second questionnaire; however, the analysis suggested no significant bias between those who filled out the second questionnaire and those who did not. Sixty-five percent of the treatment group, 51 percent of the control group, and 53 percent of the selected group returned the second questionnaire. Conviction records and police files for all three groups were also used for analysis.
Of the participants in this randomized controlled trial, 9 nine percent were women, the average age was 35 years, and 73 percent were Swiss nationals. Less than half of the participants were fully employed. Fifty-eight percent were convicted for a traffic offense, 22 percent for a criminal code offense, and 18 percent for a drug offense.
Three follow-up periods were included in the analysis: 5 years after program participation, a second 5- year period after participation, and an overall observation period of 11 years. Data analysis included chi-squared tests.
