| Nonlinear Dynamics, Psychology, and Life Sciences, Vol. 17, Iss. 3, Jul, 2013, pp. 385-403 @2013 Society for Chaos Theory in Psychology & Life Sciences Intention to Use Condom, Cusp Modeling, and Evaluation of an HIV Prevention Intervention Trial Abstract: Adolescents are at particularly high risk to acquire HIV infection;
increasing the likelihood of condom use is an effective measure to reduce the
risk of such infections. Challenges in assessing actual condom use behavior among
early adolescents render the precursor measure, intention to use condoms, an
appealing alternative. While analyzing data from a randomized controlled trial
to evaluate a theory-based intervention program to promote condom use among early adolescents,
we observed a modest effect with regard to condom use intention when the
linear analytical approach was used. If intention, as a measure of the readiness
to perform a behavior, also contains a nonlinear discrete component, it would be
more appropriately modeled using a nonlinear approach. In this study, data from a
randomized controlled trial (N=1360) were analyzed using the cusp catastrophe method
with HIV knowledge and condom skills as the asymmetry variables and condom use self-efficacy
as the bifurcation variables. Findings from concurrent and
longitudinal modeling analyses indicated a much better fit of the cusp model (R2 = 0.85);
AIC and BIC were one-fourth that of than the linear (R2 lt; 0.10) or the logistic model (R2 lt; 0.15).
Receipt of the intervention as an asymmetry variable was significantly predicted condom use
intention but did not as a bifurcation variable. In conclusion, adolescent intentions to
use a condom contain both a continuous process and a discrete process and can better be
modeled with cusp catastrophe methods. A much greater program effect is likely from the
same prevention intervention if additional measures are taken to foster sudden changes in
condom intention. Keywords: behavioral intention, cusp modeling, HIV/AIDS, Bahamian youth, condom use |