de Vet Emely, de Nooijer Jascha, de Vries Nanne K, Brug Johannes
Department of Health Education and Promotion at the Universiteit Maastricht, Maastricht, The Netherlands.
Am J Health Promot. 2005 Mar-Apr;19(4):278-85. doi: 10.4278/0890-1171-19.4.278.
To examine associations between decisional balance, self-efficacy, fruit intake, and stage of change transition from precontemplation and contemplation with cross-sectional and longitudinal methods.
A longitudinal cohort study with the use of electronic questionnaires was conducted. Three measurements were analyzed cross-sectionally, and the two intervals between the measurements were analyzed longitudinally.
A random sample of 1500 individuals from an existing Dutch Internet panel resulted in a cohort of 735 individuals. Of the cohort, 648 (response rate 88%), 592 (response rate 81%), and 570 (response rate 78%) respondents completed questionnaires at the start of the present study (T1), 53 days after T1 (T2), and 106 days after T1 (T3), respectively.
Mean age was 37.5 years, 51% were women, and 57% ate less than the recommended intake of 250 g of fruit per day.
Questionnaires included items measuring stage of change, factors favoring (pros) or working against (cons) behavior change, and self-efficacy. A food frequency questionnaire was used to assess fruit intake.
Logistic regression analyses showed that pros, fruit intake, and self-efficacy predicted forward stage transition from precontemplation. Self-efficacy predicted forward stage transition from contemplation. Cons did not predict stage transitions. Results from longitudinal analyses were similar to cross-sectional results, except for self-efficacy: no differences between early stages in self-efficacy were found, whereas self-efficacy predicted these early stage transitions.
Within the limitations posed by the sampling frame, results provided support for the Transtheoretical Model, although determinants might not always be stage specific.
