Using theory to plan appropriate interventions: cancer prevention for older Hispanic and non-Hispanic white women

Research on cancer prevention among Hispanics and non-Hispanic whites (Anglos) has focused on identifying differential barriers they encounter. Although the information has been helpful in adapting traditional interventions for Hispanic clients, changes have not generally been theory-based. This research explores the applicability of value-expectancy theory, which holds that the likelihood of taking action is a function of the perceived value of the goal and the expectancy of achieving it, with 26 Anglo and 24 Hispanic women. Value was operationalized as perceived effectiveness, and expectancy as perceived difficulty of adopting 11 specific recommended behaviours. Likelihood of adopting or maintaining the behaviour in the coming year was the dependent variable. Subjects used a direct ratio scaling method, magnitude estimation, to give estimates of the variables. Substantial variation in likelihood was explained in both groups (adjusted R2 = 0.49 for Anglos and 0.53 for Hispanics), but only difficulty was significant for both Anglo and Hispanic groups. The relationship between difficulty and likelihood was curvilinear, with likelihood decreasing rapidly as difficulty increased slightly. Results suggest the theory can be used to develop interventions for both groups and that these should focus on decreasing the individual's perceived difficulty of adopting and maintaining cancer prevention activities.