Evaluation of a print intervention aimed to improve healthy eating and physical activity among low educated women from various ethnic backgrounds.

Unhealthy nutrition and physical activity (PA) behaviors are prevalent among Dutch, Turkish and Moroccan women in the Netherlands, especially among those having a low socioeconomic status (LSES). Hence, there is a need for health promoting interventions to improve these behaviors among this specific target group. Computer-tailoring interventions were shown to be effective in improving a variety of health behaviors. Most of these interventions, however, do not account for the socioeconomic status and ethnic identity (EI) of the target groups. Therefore, two computer-tailored interventions aimed at improving dietary and PA behavior among adult Dutch, Turkish and Moroccan LSES women were developed. One intervention is tailored to cognitive variables and self-regulation processes, while the other is additionally tailored to EI, i.e. to which degree someone identifies with an ethnic group. This trial aims to evaluate the effects of these two interventions among women from the target group, aged between 20 and 65 years.
Both interventions will consist of a sequence of three brochures including written advice messages about two out of four goal behaviors: increased fruit consumption, increased vegetable consumption, decreased high-energy snack intake and/or increased physical activity. The messages of one intervention (intervention 1) are tailored to motivational factors, such as attitude and self-efficacy. The messages and lay-out of the other intervention (intervention 2) are additionally tailored to EI. This is achieved by using messages, colors, patterns and role models the participants can identify with.
The interventions will be evaluated in a randomized controlled trial with three study arms: intervention 1, intervention 2 and a control group receiving general information about the goal behaviors. 1000 LSES women of Dutch, Turkish and Moroccan origin aged between 20 and 65 years will be recruited for participation. Assessment moments will be at baseline, and at 1, 3 and 9 month follow-up (after having received the first brochure). Primary outcome-measures will be fruit consumption, vegetable consumption, high-energy snack consumption and physical activity level.
We received a declaration of the cETO in Heerlen (a commission that appraises the ethical respectability of scientific research) that this trial does not require MEC approval, as it does not come under the Dutch WMO law (i.e. the law that defines the rules concerning medical scientific research).

This trial aims to evaluate the effects of two computer-tailored print-delivered interventions aimed at improving dietary and PA behavior among adult Dutch, Turkish and Moroccan LSES women. One intervention is tailored to cognitive variables (Intervention 1), while the other intervention is additionally tailored to ethnic identity (EI), i.e. to which degree someone identifies with an ethnic group (Intervention 2). In order to evaluate the effectiveness of the interventions, they will be compared to a control group receiving an intervention that provides general, non-tailored advice.

The following hypotheses will be tested:

1. Both interventions will be more effective in improving healthy eating and physical activity than the control intervention providing general, non-tailored advice.
2. The effect sizes of intervention 2 will be larger than the effect sizes of intervention 1.
3. The intervention effects will be mediated by cognitive determinants of healthy eating and physical activity (awareness of own health behavior, attitude, self-efficacy, social support and intention).
4. Moderation of the intervention effects by socio-demographic factors will be explored (i.e. ethnicity, ethnic identity, age, living situation, number of children).
5. A process evaluation will be conducted to assess likability of the intervention.

T0: baseline measurement, about two weeks before start of the intervention

T1: 1 month post intervention

T2: 3 months post intervention

T3: 9 months post intervention

Intervention tailored on cognitive determinants only (intervention 1):

This intervention consists of tailored advice messages to improve two out of four behaviors among the participants: increased fruit consumption, increased vegetable consumption, decreased high-energy snack intake and/or increased physical activity. The messages are tailored to motivational factors, such as awareness of own behavior, attitude towards the behavior and self-efficacy to perform the behavior. Moreover, the intervention is tailored to self-regulation stages, such as goal setting and planning.



Intervention tailored on cognitive determinants and ethnic identity (intervention 2):

This intervention is identical to intervention 1, with the exception that it additionally provides ethnic identity (EI) tailoring. EI-tailoring implies that the intervention is not only tailored to motivational and self-regulation factors, but also to the participants’ EI. EI is defined as the degree to which someone identifies with a particular ethnic group. Eight EI categories will be distinguished. Advice messages of intervention 2 are adjusted by referring to food or cultural customs important in a particular EI category. The lay-out is adjusted by using certain colors, patterns and symbols which are common in the EI category. Moreover, matching role model are used conform each EI category (e.g. by using Turkish or Moroccan role models for participants from Turkish or Moroccan origin).

Control intervention:

The control intervention consists of general advice messages on two out of four behaviors: increased fruit consumption, increased vegetable consumption, decreased high-energy snack intake and/or increased physical activity. These messages will not be tailored to motivational and self-regulation factors, or to EI.



All three interventions:

All three of the interventions consist of 3 brochures: brochures 1 and 2 include advice about two of the four goals behaviors (e.g. brochure 1 about fruit and brochure 2 about physical activity). Brochures 1 and 2 will be handed out after the baseline measurement. Brochure 3 includes follow-up advice about the two behaviors from brochures 1 and 2, and will be handed out after the first follow-up measurement.