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Findings from RCT Grants

Long-term (6.5-Year) Impact of the PROSPER Youth Substance Abuse Prevention System on Medicaid-Covered Emergency Department Utilization

This well-conducted RCT follow-up found (i) no statistically significant effect on the average number of Medicaid-covered emergency department visits; and (ii) a statistically-significant 23% ($26 per youth) reduction in Medicaid-covered emergency department costs.

GranteePennsylvania State University. The full study report is linked here.

Description of the Intervention. This is a randomized controlled trial of Promoting School-community-university Partnerships to Enhance Resilience (PROSPER) – a program-delivery system in which universities partner with community teams to implement evidence-based programs for preventing youth substance abuse and other problem behaviors. Each participating community (i.e., town or small city) forms a community team of 8-12 people, which works with a state-level team of university researchers to select and implement (i) one evidence-based, family-focused program to deliver in 6th grade, and (ii) one evidence-based, school-level program to deliver in 7th grade. PROSPER’s cost per participating youth totals about $410-$440 over 6th and 7th grade when implemented in a typically-sized community of 25,000 residents.

Previous reports on this RCT have presented findings based on the original sample of 28 rural towns and small cities in Iowa and Pennsylvania (14 treatment and 14 control), containing a total of approximately 12,000 students who started 6th grade in 2002 or 2003. Those reports found that, at the 6.5-year follow-up (end of 12th grade), PROSPER produced (i) reductions of 10-35% in illicit drug use initiation by youth who were non-users in 6th grade (prior to program delivery), and (ii) moderate reductions in substance use for the full sample – non-users and users (e.g., 14% lower likelihood of past-month cigarette use).

Study Design. This project was a further analysis of the aforementioned RCT, which examined whether PROSPER reduced Medicaid utilization by the youth in the sample, as measured with administrative data from the Centers for Medicare and Medicaid Services. This analysis used a sample of 34,382 students, including the original sample of students (who started 6th grade in 2002 and 2003) plus all students in the 28 randomized communities who started 6th grade between 2005 and 2008.1 91% of the youth were white and 51% were enrolled in Medicaid during the follow-up period.

Impact on the Primary Outcomes. The new analysis found the following impacts on the study’s two primary pre-registered outcomes, measured over a period of approximately 6.5 years after random assignment (ages 12-18): (i) no significant effect on the average number of Medicaid-covered emergency department visits; and (ii) a statistically-significant 23% reduction in Medicaid-covered emergency department costs, which equates to $26 per youth. The dollar value of this cost reduction is modest because Medicaid-covered emergency department costs were low in both the treatment group (averaging $85 per youth) and control group (averaging $111 per youth).2

Study Quality. Based on a careful review, we believe the study’s analysis was well-conducted and produced valid findings.3

  1. 1

    The researchers were able follow the four additional cohorts of sixth grade students because almost all communities randomly assigned to receive PROSPER continued to implement it faithfully for an additional four years and no control communities took up the intervention.

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  2. 2

    The researchers hypothesize that one reason they found a significant effect on emergency department costs, but not on average number of emergency department visits, is that PROSPER was particularly effective in preventing more severe (and thus more costly) emergency episodes. One suggestive piece of evidence supporting this hypothesis is that the study also found statistically-significant effects on average number of Medicaid-covered inpatient visits (a reduction of 18%) and their associated costs (a reduction of 12%, or $16 per youth), both of which were secondary outcomes examined in the new analysis.

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  3. 3

    For example, the study had successful random assignment (as evidenced by highly similar treatment and control groups), no sample attrition (as outcome data were available for all youth in the sample), and valid analyses that were publicly pre-registered and accounted for the fact that communities, rather than individual youth, were randomly assigned.

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