Lecture 17 Cross sectional studies Flashcards
descriptive epidemiology definition
distribution of health-related
states or events in specified populations…”
Analytic epidemiology definition
determinants of health-related states or events in specified populations…”
what is descriptive epidemiology?
- ‘Person, place and time’
- Observational
- What
- Who
- Where
- When
what is Analytic Epidemiology?
• Associations: exposures and outcomes • Causation • Observational or intervention studies
• Why
What is a cross-sectional study?
Measures exposures and/or outcomes at one point in time
What do we mean by a ‘point in time?’
A particular date eg (14 August 2019)
A specific event eg (visit to doctor, retirement)
A specific period of time eg (in the past 12 months)
Some examples of cross-sectional studies
New Zealand Health Survey
Census of Populations and Dwellings
Youth 2000 National Youth Health and Wellbeing Survey Series
why are Cross sectional studies used?
Describe Prevalence of exposures or health conditions in a population
Compare prevalence amongst different groups in a population
What do cross-sectional studies measure?
Prevalence: the proportion of a defined population who have a disease at a point in time
Prevalence is affected by
incidence AND duration
What are cross-sectional studies used for?
To describe:
Prevalence of exposures or health conditions in a population
E.g. What is the prevalence of osteoarthritis in NZ?
To compare:
prevalence amongst different groups in a population
E.g. what is the prevalence of osteoarthritis in NZ for people of different ages?
To compare:
Compare repeated studies over time
E.g. Has the prevalence of smoking changed over time among high school students?
To generate hypotheses:
E.g. Which factors are associated with low back pain among nurses?
To plan:
health services
E.g. Population of Nelson Marlborough DHB Population by age 2015/16
Recap: Cross-sectional studies measures
exposures and/or outcomes at one point in time
prevalence (affected by incidence and duration)
Recap: Cross-sectional studies used to
describe prevalence
compare prevalence
generate hypotheses
plan (e.g. health service delivery)
GATE frame
Graphic Appraisal Tool for Epidemiological studies:
Gate frame used for
Describe main elements of epidemiological study