Determinants of Behavioral Intention to Change Sexual and Reproductive Health Practices Among Adolescents: A Hierarchical Multiple Linear Regression Analysis

Abstract

Conventional and web-based sexual and reproductive health (SRH) interventions are increasingly used with adolescents, yet their comparative effectiveness and underlying mechanisms remain unclear. This study compared the two formats and examined the Theory of Planned Behavior (TPB) constructs as predictors of changes in intention to adopt health-protective SRH practices (including contraceptive use, service utilization, and parent–child communication) among Malaysian adolescents. A randomized controlled trial allocated adolescents to conventional or web-based SRH education. Intention-to-change behavior towards sexual and reproductive health scores was assessed at baseline, 1 month, and 3 months; change scores were modeled using hierarchical linear regression, including intervention type, sociodemographic factors, and TPB-related changes in knowledge, attitude, subjective norm, control beliefs, perceived power, and perceived control. The conventional intervention produced significantly higher intention-to-change scores at 1 and 3 months, with moderate-to-large effects. In regression analyses (N = 209), Model 1 (type + demographics) significantly predicted change in intention (adjusted R² = .074), with only intervention type significant. Model 2 (adding TPB change scores) improved the fit (adjusted R² = .120; ΔR² = .069, p-value = .014), with perceived power positively and control beliefs inversely associated with change in intention; intervention type was no longer significant. Adolescents in the conventional group showed a larger and more sustained increase in intention to change their SRH behaviors than those in the web-based group, an effect that appeared to operate through changes in underlying psychosocial factors such as control beliefs and perceived power.