Illicit use of prescription stimulants in the college population: Theory-based instrument development and examination

Background: The illicit use of prescription stimulants (IUPS) is a critical Public Health problem in the college population. The goal of this project was to better incorporate the use of health behavior theory to explain, predict, and ultimately, prevent the behavior. Methods: The study, guided by the Theory of Triadic Influence (TTI), included five phases of research completed at one university located in the Pacific Northwest: 1) Measurement development via a systematic review of the IUPS literature, 2) Instrument review by five health and measurement professionals, 3) Group interviews with six college students, 4) Pilot testing using test-retest methodology with 39 college students, and 5) A paper-based campus study using one-stage cluster sampling (N = 520 students in 20 classrooms, eligible student response rate = 96.30%). Nested logistic regression analyses and structural equation modeling (SEM) were used on responses from the phase V sample to test study hypotheses. Results: The Behaviors, Expectancies, Attitudes and College Health Questionnaire (BEACH-Q) had demonstrated reliability (i.e. internal consistency and stability) and validity (i.e. face, content, and predictive). The prevalence of IUPS during college self-reported by the phase V undergraduate student sample was 25.58%. Nested logistic regression and SEM illustrated the multi-etiological nature of IUPS. Discussion: The developed measure was theory-driven, broadly defined IUPS, and was psychometrically strong. IUPS was prevalent on the campus under investigation, as one in four undergraduate students had engaged in the behavior during college. The findings also suggest that prevention and intervention plans should be multifaceted in nature.