Epidemiology of Coronary Heart Disease Flashcards
Define epidemiology.
The study of the distribution and determinants of health- related states or events in specified populations and the application of this study to the control of health problems.
Identify the main stages of an epidemiological approach (and identify the type of approach required for each).
1) Describe the health status of a population: descriptive study (describe by time, place and person)
2) Understand the natural history of a condition: longitudinal studies
3) Identify causes of medical problems: observational studies (cohort, or case-control)
4) Act/Evaluate medical and health promoting interventions: Randomized Controlled Trials. Can monitor (routine data, observational studies) or intervene (experimental studies)
Identify the broader determinants of health.
Social environment
Physical environment
Genetic endowment
Define numerator and denominator in the context of epidemiology.
Numerator
• clinical condition (e.g. who has made the diagnosis, how, on what criteria, ICD10 code etc)
Denominator
• Who makes up the ‘population at risk’
What proportion of all deaths in males does coronary heart disease account for ?
14%
Describe coronary heart disease in terms of time, place and person.
Time: Decrease in mortality rate from CHD in the UK over the years
Place: Different UK counties have different mortality rate from CHD
Person: (Person related attributes including risk factors)
Define age standardized rate.
” Two populations with the same age-specific mortality rates for a cause of death will
have different overall death rates if the age distributions of their populations are different. Agestandardized
mortality rates adjust for differences in population age distribution by applying the
observed age-specific mortality rates for each population to a standard population.é
Identify risk factors of CHD (the factors making up the “person” aspect of the descriptive stage of epidemiology).
• Un-modifiable: – Age – Sex – Genetic factors --Race and ethinicity
• Modifiable:
– Personal risk factors (HABITS) (e.g. smoking, high blood pressure, high blood cholesterol, diabetes, physical inactivity, obesity,)
– Social risk factors (HOUSEHOLD) (e.g. employment, income, culture)
– Environmental risk factors (HABITAT) (e.g. deprivation, housing, pollution)
Describe the main steps of disease progression (i.e. natural history of the disease).
- Disease Onset
- Symptoms
- Seek Care
- Diagnosis
- Treatment
- Outcome (cure, control disability, death)
Define what is meant by a longitudinal study. Provide an example of a longitudinal study in relation to CHD.
“Data is gathered for the same subjects repeatedly over a period of time”
E.g. “ survival curves for all-cause death, according to the presence of angina or ischaemic changes on an electrocardiogram (ECG) in men (in West of Scotland)”
Define what is meant by cohort study.
• Select people without an outcome
• Classify according to an exposure
• Follow-up
– Prospective (The investigators design the questions and data collection procedures carefully in order to obtain accurate information about exposures before disease develops in any of the subjects. After baseline information is collected, subjects in a prospective cohort study are then followed “longitudinally,” i.e. over a period of time)
– Retrospective (conceived after some people have already developed the outcomes of interest. The investigators jump back in time to identify a cohort of individuals at a point in time before they have developed the outcomes of interest, and they try to establish their exposure status at that point in time. They then determine whether the subject subsequently developed the outcome of interest.)
• Compare RISK of disease in exposed and unexposed
What is a risk factor according to the Framingham Study ?
Aspect of ... • personal behaviour • life style • environmental exposure • genetic trait
which on the basis of epidemiological evidence…
• is associated with a health-related condition
• considered important to prevention
Identify the main types of ‘risk factor’.
• Marker of Risk
– associated with the probability of disease but not causal
• Causal Risk Factor (Determinant) – associated and causal
• Modifiable Risk Factor
– causal and can be modified by intervention
Describe the main features of the Framingham study.
-Cohort Study
-Objective: Identify the common factors or characteristics that contribute to CVD by following its development over a long period of time in a large group of participants who had not yet developed overt symptoms of CVD or suffered a heart attack or stroke
-Subjects: Males and Females from Framingham Massachusetts, aged 30 and 62
- Extensive physical examinations and lifestyle interviews were conducted
• Subjects have continued to return to the study every two years for a detailed medical history, physical examination, and laboratory tests
Define ASSIGN score.
“ASSIGN is a cardiovascular risk score which uses risk factors (including social deprivation) to calculate CV risk”
