GHB: from knowledge about determinants to evidence-based health promotion interventions

1. Gjalt-Jorn Ygram Peters1 & Gerjo Kok1 (see handout for references and details) (this poster is available at http://ecstasyresearch.eu?q=posters) Introduction Method • Gamma hydroxybutyrate (GHB) use is increasing. • Therefore, evidence-based health promotion is desired. • This requires an evidence base  research question: • What are the determinants of GHB use? • We conducted an online survey in the Dutch dance scene • Data was collected in two waves which were 5 months apart t1: N = 3131 Februari-July 2006 Measures: determinants & GHB use t2: N = 1918 July-December 2006 Measures: GHB use Sample (n = 3131) Gender distribution: Age distribution: GHB prevalence at t1 50.4% female; 49.6% male Party frequencies: Education level distribution: 24.5% ever used; 75.5% never did 14.5% uses GHB; 85.5% does not 20.7% every 6 months or less; 25.0% every 4-6 months; 32.6% every 2-3 months; 15.6% monthly; 6.2% 52.4% lower; 47.6% higher education Belief-intention correlations GHB . . . Non-users (n = 2811) Diff. (q) GHB users (N = 303) r = .16 r = .13 R2 = .26 r = .16 r = .24 makes me excited/horny .18*** -.03 .21*** r = .11 r = .09 makes me happy .24*** -.11 .34*** Attitude Attitude Subjective norm Subjective norm Self-efficacy Self-efficacy makes my worries dissappear .07*** .00 .08 r = .31 β = .22 r = .22 β = .16 All participants r = .16 β = .07 r = .10 β = .05 r = .35 β = .33 r = .45 β = .39 helpt me be disinhibited .14*** -.03 .17** makes the world seem nicer .12*** .03 .09 helps me relax .25*** .03 .22*** d = 2.6 d = 2.4 Intention Intention GHB use GHB use is likely to make me go ‘out’ .21*** .02 .19*** (all p-values < .0001) (all p-values < .0001) eases socializing with people .14*** .01 .13* makes me feel tired .00 -.16** .16** makes me hungry -.05* .27*** -.30*** is healthier than ecstasy .30*** -.16* .43*** R2 = .16 is healthier than alcohol .27*** -.11 .37*** is dangerous .16*** .09 .07 is easy to obtain -.04* .01 -.06 has a positive image .11*** .23*** -.12* Only non-users is easy to overdose on .00 -.04 .04 enhances sex .22*** -.10 .31*** causes a hangover .26*** -.13* .38*** is used unhealthily by many people .05** .01 .04 Discussion & conclusions • Intention strongly predicts GHB use • Initially, is appears we understand 26% of GHB use intention • However, seperate analyses show: • We understand only 16-17% of intention • Different determinants for non-users’ and users’ intention • Expectancy-based beliefs predict intention weakly/moderately • Expectancy-based beliefs predict intention differentially • Future research: • Need for qualitative studies into reasons for GHB use • Maintain distinction between non-users and users R2 = .17 r = .09* r = .21 r = -.03* Attitude Subjective norm Self-efficacy Only GHB users r = .11* β = .03* r = .01* β = -.06* r = .41 β = .40 d = 1.4 Intention GHB use (all p-values < .01, except * not significant) GHB: from knowledge about determinants to evidence-based health promotion interventions