Doelgroepsegmentatie in de primaire preventie van cardiovasculaire ziekten

Profiles of target groups (target group segmentation) in the primary prevention of cardiovascular disease (CVD), can lead to an effective target group-directed approach in health education. Objectives in this thesis are: 1) To identify demographic and socioeconomic characteristics of such target groups. 2) To find personal and environmental determinants of preventive health behavior, which are useful as guidelines for intervention.Segmentation was performed on the basis of health behavior regarding cardiovascular risk factors like inadequate nutrition habits, smoking, obesity, and physical inactivity. Using linear discriminant analysis we examined for each of these life-style habits, which of a series of characteristics discriminated between the target group and a preventive group. This multivariate technique yields the independent contribution of a determinant by controlling for confounding.Data have been collected through a cross-sectional survey about knowledge, attitude and behavior regarding cardiovascular risk factors among the Dutch population in the age of 18 to 64 years. The study was carried out in 1978 by interviewing a national, stratified random sample of 889 men and 1,062 women. All participants were personally interviewed at their homes according to a partially structured questionnaire.Chapter 1 describes determinants of health and cardiovascular risk, in particular the role of life-style. Also the use of primary prevention and target group segmentation are discussed.In Chapter 2 we studied the interrelationship of different life-style habits. Although some risk habits were associated, the results did not suggest systematic clustering: a combination of three or four risk habits in one person did not occur more often than one would expect on the basis of probability. Because of the high prevalence of multiple risk habits and their cumulative effect on CVD risk, health education on a prudent life-style is still to be recommended. Segmentation identified as target group: men, with low level of education and occupation. Dissemination of knowledge and attitude change through audiovisual mass media can stimulate preventive health behavior.In Chapter 3 those individuals are characterized with dietary habits that were thought to increase CVD risk. Comparison with a group with a desirable food consumption pattern by means of discriminant analysis indicated that the target group included more men, in the age of 18 to 44 years, from large families and in the lower socioeconomic strata. According to the target group's preference, nutrition education methods should include audiovisual mass media as well as group counseling or face-to-face instruction directed at young families. Educational objectives are: increasing knowledge (composition of food products and meals), stimulating motivation for change and learning personal skills (food selection and preparation of wholesome meals).Chapter 4 deals with the dietary history recall method that evaluated the quality of the food consumption pattern. The questionnaire focussed on nutrients considered as important in a diet aiming at prevention of CVD: fats, polyunsaturated fats, simple carbohydrates, cholesterol, dietary fiber, and alcohol. To assess the preventive value of the diet, a food scoring system based on the criteria of a prudent diet was constructed. The rationale behind the scoring procedure was that frequent use of foods which are optimal from a preventive point of view leads to a high score.The method was validated on quantitative seven-day-record data and seems to be applicable in nutrition education programs. For the analysis in Chapter 3 the upper 30 percent of the nutrition score distribution was labeled desirable and the lowest 30 percent as undesirable food consumption pattern.In Chapter 5 results are presented of the relationship between body mass index (BMI) and sociodemographic and life-style characteristics. Because of the U-shaped relationship with overall mortality, BMI was introduced as continuous variable in a linear regression to avoid an arbitrarily chosen reference group.In both sexes, a strong positive association was found with age and a negative one with level of education. Irrespective of own level of occupation and education women with high familial social class had a lower BMI. Sedentary living was positively related to overweight in women. Among men an inverse relationship was revealed for unemployment and a U-shaped pattern for smoking: non-smokers and heavy smokers had the highest BMI. No effects were identified for alcohol consumption and leisure time physical activity. An inventory of opinions relating to dietary habits and physical exercise may be useful for therapy.The differences of smokers, who failed in one or more cessation attempts of at least one month and ex-smokers - those who quitted at least a year ago - are reported in Chapter 6. This contrast was studied because the increase of non-smokers in the Netherlands in the seventies was hardly the consequence of a rise in the number of ex- smokers.The profile of the failing quitter could aid to give up the smoking habit successfully. Failing attempts were associated with men, younger age (18-34 year), a low educational level and divorced/widowed status. The fact that several univariate differences disappeared in a multivariate model, was in agreement with other findings of intercorrelation among smoking predictor variables e.g., tobacco consumption, number of inhalers, alcohol intake, skipping breakfast, obesity and leisure-time physical inactivity. These and other findings may be useful to design more effective smoking cessation programs.In Chapter 7 we identified those individuals who did not exercise regularly in leisure time. Sixty minutes per week engaging in sports or its equivalents in cycling (75 min/week) or walking (90 min/week) were cut-off points in classifying active and inactive subjects. Inactivity was defined as limited or not regular practice of any activity. Those who regularly participated in at least two activities and exceeded the time limits were classified as active.After adjustment for sedentary living, independent determinants of the target group were older age (55-64 yr), lower educational attainment and large families. Therefore programs promoting physical fitness, stimulating motivation, and encouraging social support, should address older people and large families.Chapter 8 includes a general discussion and guidelines for health education. Sources of bias (selection, information, and confounding bias) that may affect the validity of the results, the choice of the contrasts for segmentation, and the importance of multivariate analysis are discussed.Our study with its shortcomings is placed in a framework for planning of health education in solving health problems. For target group-directed educational programs, we gave guidelines for contents and methods and arguments to prefer a 'population-strategy' over a 'high-risk-strategy' in a prevention policy.Finally we dealt with a topic of discussion in health education: to advise or to inform the public.