Background: Little is known about how interventions motivate individuals to change multiple health risk behaviors. Self-determination theory (SDT) proposes that patient autonomy is an essential factor for motivating change.
Objective: An SDT-based intervention to enhance autonomous motivation for tobacco abstinence and improving cholesterol was tested.
Design: The Smokers' Health Study is a randomized multiple risk behavior change intervention trial.
Setting: Smokers were recruited to a tobacco treatment center.
Patients: A total of 1.006 adult smokers were recruited between 1999 and 2002 from physician offices and by newspaper advertisements.
Interventions: A 6-month clinical intervention (4 contacts) to facilitate internalization of autonomy and perceived competence for tobacco abstinence and reduced percent calories from fat was compared with community care. Clinicians elicited patient perspectives and life strivings, provided absolute coronary artery disease risk estimates,enumerated effective treatment options, supported patient initiatives,minimized clinician control, assessed motivation for change, and developed a plan for change.
Outcome measures: Twelve-month prolonged tobacco abstinence, and change in percent calories from fat and low-density lipoprotein-cholesterol (LDL-C) from baseline to 18 months. RESULTS- Intention to treat analyses revealed that the intervention significantly increased 12-month prolonged tobacco abstinence (6.2% vs 2.4%; odds ratio [OR]=2.7, P=.01, number needed to treat [NNT] =26), and reduced LDL-C (-8.9 vs -4.1 mg/dL; P=.05). There was no effect on percent calories from fat.
Conclusions: An intervention focused on supporting smokers'autonomy was effective in increasing prolonged tobacco abstinence and lowering LDL-C. Clinical interventions for behavior change may be improved by increasing patient autonomy and perceived competence.