Intro to epidemiology Flashcards
what is epidemiology
study of distribution and determinants of health events an health related factors in specified populations and the application of this knowledge to plan and evaluate strategies to prevent or manage disease in population
what are the objectives of epidemiology
history of disease community diagnossis measure risk assessment, evaluation, research complete clinical picture identification of syndromes determine the cause of disease
Give examples of epidemiological measuresd
measure of frequency (prevalence, incidence)–>measures of association (odds ratio)->measures of impact (attributable risk)
How to calculate measures of frequency (incidence rate and prevalence date
Incidence rate=(total no. new cases during given time period/total population at risk during same time period)100^n
Prevalence rate=(all new and pre-existing cases of a specific disease during given time period/total population during the same period)10^n
How to calculate risk ratio (cumulative incidence ratio) in measures of association
Cumulative incidence in case/cumulative incidence in control
What is used to measure potential impact and what calculation is used
attributable risk=((incidence exposed-incidence unexposed)/incidence exposed)*100
obtained is the % of occasions when outcome is attributed to exposure
Types of epidemiological investigations and its applications
descriptive: patterns of disease occurence, by person, time and place, easily accessible data
Application-vital stats, periodic surveys, comparisons, program planing, hypotheses generating, future research
Analytiical: disease etiology, resource intensive, comparison groups
Application-determinants of disease, hypotheses testing, modes of transmission
Epidemiological study designs and its concerns
Experimental: RCT (manipulation, control, randomisation, blinding) Concerns=unethical
Observational: cohort study, case control study, crosss sectional study (non experimental, non controlled, natural grouping, time, doesn’t interfere/manipulate) Concerns=confounding, selection bias, measurement errorrs
What kind of epidemiological study errors can you get
Selection bias (self selection=volunteers tend to be different, non response=some participants might refuse to answer, attrition=unequal loss of participants, selective survival) Information bias (reporting bias, flase positives/negatives, errors and omissions in medical records) Confounding (differences in age, gender health status)
