Transtheoretical Model Intervention for Adherence to Lipid-Lowering Drugs

Abstract

An estimated 60% of individuals prescribed lipid-lowering medications are nonadherent. Failure to adhere increases morbidity, mortality, healthcare utilization, and healthcare costs. This study examined the effectiveness of a population-based, individualized Transtheoretical Model (TTM) expert system intervention to improve adherence and increase exercise and diet in a randomized 18-month trial involving 404 adults. Compared to usual care, treatment participants who started in a pre-action stage were significantly more likely to be in the Action and Maintenance (A/M) stages for adherence at end of treatment (55.3% versus 40%, z = 2.11, p < 0.05, h = 0.31) and at 18-months (56% versus 37.8%, z = 2.38, p < 0.01, h = 0.36). The treatment group scored significantly better on two measures of adherence at six and 12 months post-treatment (all p < 0.05, odds ratios [OR] 1.49-3.67). Among those who began in A/M, treatment participants were significantly more likely to remain in A/M at 18 months (85.2% versus 55.6%, z = 2.63, p < 0.01, h = 0.67). Those receiving treatment were significantly more likely to progress to A/M for exercise and dietary fat reduction (43.3% versus 24.7% for exercise, and 24.7% versus 12.5% for diet). TTM expert system interventions can have a significant impact on entire populations for adherence. Results for dietary fat and exercise suggest covariation of treatment effects.

Validating stage of change measures for physical activity and dietary behaviors for overweight women

“…37 Such an approach not only allowed for tests of hypothesized stage differences at several points among the five stages, but also tests differences in behavior between pre-action stages and the action and maintenance stages, which has often served as the point of between-group comparisons in previous studies. [38][39][40] The distribution of individuals across stages of change for a health behavior varies by the nature of the population. Broad population-wide surveillance derived from proactive (for example, random digit dialing), sampling methods can provide estimates of the proportion who have reached a health behavior recommendation and proportion who could benefit by changing, and also their level of motivation to change.…”

Transtheoretical Model-based multiple behavior intervention for weight management: Effectiveness on a population basis

“…Questions may be raised about why the control group did as well as they did, a finding that has emerged in other population-based intervention studies (e.g., Johnson et al, 2006;Evers et al, 2006). A leading hypothesis is that individuals assigned to the control group received much more than "usual care."…”

“…A second study demonstrated that TTM interventions had significant effects at 24 months on four behaviors: smoking, dietary fat, sun exposure, and mammography (Prochaska et al, 2005). Johnson et al (2006) reported that, when paired with fully tailored interventions for lipid-lowering medication adherence, stage-matched interventions had significant effects on physical activity and dietary fat reduction.…”

Multiple health behavior change research: An introduction and overview

“…Further, among smokers in the three trials, treatment of one or two coexisting risk factors (diet and/or sun exposure) did not decrease the effectiveness of smoking cessation treatment, and treatment for the co-existing factors was effective as well. A fourth population-based, stage-based, expert system intervention targeting individuals with high cholesterol reported significant effects on lipid medication adherence, physical activity, and dietary fat reduction (Johnson, et al, 2006). A fifth population-based trial, targeting weight management, smoking, stress, and inactivity demonstrated significant effects at 6-months follow-up for a repeated stage-based expert system intervention or three motivational interviewing counseling sessions relative to a health risk assessment with brief feedback condition (J. O.…”