Epidemiological Paradigms: Adult Risk Factor Approaches
Epidemiological paradigms are examples or models of how things can be interpreted and explained. There are number of different paradigms but this section focuses on three epidemiological influences throughout life:
- Programming
- Adult risk factor approaches
- Life-course
2. Adult risk factor approaches
Theory & Evidence
The adult risk factor approach considers the aetiology of chronic disease to be primarily as a result of adult behaviours and risk factors such as diet, smoking, physical inactivity. The adult risk factor approach is therefore defined as the impact of behaviours, such as smoking, diet, exercise and alcohol consumption, on the onset and progression of diseases in adulthood. The theory is also known as the 'lifestyle approach'.
The approach was introduced after the 2nd World War when cardiovascular disease mortality rose sharply in Western Countries and targeting the adult diet and lifestyle was seen as key to both the management and prevention of many of the chronic diseases. Interventions introduced to address adult risk factors such as smoking, obesity, elevated blood pressure and cholesterol levels have been shown to have had major impacts on reducing chronic disease prevalence.
The model uses an integrated approach by controlling a small number of risk factors that may have a major impact on a large number of diseases because a number of chronic diseases have risk factors in common and many risk factors are relevant to more than one chronic disease. The approach is therefore considered to have greater efficiency than interventions aimed at disease specific approaches. The relative contributory effects of each risk factor are able to be assessed using multiple regression. Figure 1 demonstrates the common risk factor approach.
Adapted from Sheiham and Watt (2000) by Hannah Pheasant 2008.
The major risk factors for chronic diseases are smoking, poor diet (high in saturated fats and sugars, and low in fibre and fruit and vegetables), alcohol, physical inactivity, stress and control.
The major chronic diseases include obesity, cardiovascular disease, type 2 diabetes, cancers, respiratory disease, and mental illness.
Clustering of risk factors occurs when a number of risk factors for the major chronic diseases occur in the same individual. For example, a smoker is likely to drink more alcohol, have a worse diet and take less exercise than a non-smoker. The clustering of risk factors occurs in individuals and groups, particularly those at the lower levels of the social gradient.
Limitations
Although interventions tackling adult risk factors have had positive impacts on chronic disease prevalence, the approach fails to fully explain many of the geographical and social differentials in chronic disease risk. For example, the major chronic diseases have clear social class gradients such as cardiovascular disease, respiratory diseases, and type 2 diabetes. See British Heart Study. These differentials cannot be fully attributed to the intrauterine environment (i.e. programming) and therefore the observed social gradients in health suggests that health related behaviours are significantly related to social factors. The adult risk factor approach emphasises an individual's lifestyle as a cause and solution of health problems but ignores the broader determinants of health and therefore does not take account of the more complex social factors that are associated with an individual's behaviour and lifestyle.
© Hannah Pheasant 2008
