Final answer:
It is false that case-control studies can provide a valid assessment of disease prevalence. These studies are designed to assess risk associations, while other study types like cohort studies are used to determine prevalence. Case-control studies, such as Doll and Hill's research on smoking, can show strong associations between exposure and disease incidence but not prevalence.
Step-by-step explanation:
It is false to claim that a typical case-control study can provide a valid assessment of disease prevalence. Case-control studies are designed to assess associations and calculate odds ratios rather than to measure prevalence, which is the proportion of a population affected by a disease at a specific point in time. Case-control studies compare individuals with the disease (cases) to those without the disease (controls) to quantify the relative risk associated with exposure to a certain factor, such as cigarette smoking.
Doll and Hill's landmark case-control study on smoking and lung cancer is a cornerstone example of how such studies can reveal strong associations between exposure and disease incidence. However, for establishing disease prevalence, other study designs, like cross-sectional or cohort studies, are more appropriate. Cohort studies, like the subsequent research by Doll and Hill involving British physicians, track subjects over time to measure incidence and can also contribute to prevalence data.
The false assertion regarding disease prevalence assessment aligns with the second part of the student's question, indicating that the risk difference associated with cigarette smoking is much higher for coronary heart disease. While this statement suggests that smoking significantly increases the risk, the type of study being referenced does not provide prevalence data. Epidemiological studies, both case-control and cohort, and their interplay significantly contributed to understanding health outcomes and the association of smoking with diseases such as lung cancer and coronary heart disease.