| Term | Definition |
|
epidemiology |
study of the distribution, determinants of disease frequency in terms of morbidity, injury, disability, mortality |
|
cumulative incidence (a.k.a. risk) |
new cases in a population over a given time period |
|
medical surveillance |
collation, collection, interpretation and analysis of disease data, with dissemination to those who need to know to take action |
|
Person-to-person |
causal agent spread from one person to another (e.g. Tuberculosis --> isolation, treatment of cases) |
|
case fatality |
deaths / cases (proportion, or percentage) |
|
censored |
follow-up ended before end of study (patient quits, or lost to follow-up) |
|
case-control study |
(analytical study) compare people with disease to those without (assess exposure, and determine risk of disease - odds ratio) |
|
point prevalence |
number of existing cases in population at given point in time |
|
descriptive epidemiological studies |
hypothesis generating |
|
John Graunt |
Columbus of Statistics |
|
Ecological fallacy |
aggregrate traits do not necessarily apply to individual cases |
|
screening |
detecting disease when individual is asymptomatic |
|
clinical trials |
take eligible subjects and randomize, categorize, analyze |
|
mesothelioma |
cancer caused by asbestos exposure |
|
Health Status Registry |
measures birth defects in BC children |
|
Bernardo Ramazzini |
father of occupational health (identified lead poisoning in potters; postures) |
|
3 types of disease spread |
person-to-person; zoonosis; common source |
|
3 types of descriptive studies |
case report/case series; correlational (ecological); cross-sectional surveys of individuals |
|
Ignas Semmelweiss |
recognized that handwashing could reduce peripeural mortality |
|
Incidence rate |
rapidity of new cases |
|
risk |
likelihood that exposure will lead to disease |
|
survival rate |
number living / number with disease |
|
cross-sectional studies (prevalence surveys) |
best for chronic degenerative diseases, with no clear onset and long latency |
|
confounding factors |
other factors preventing a true cause/effect relationship in correlational studies |
|
attack rate |
number ill / number exposed |
|
epidemiologists focus on: |
human populations and non-experimental observations |
|
3 benefits of surveillance |
identifying outbreaks, causes, strategies to prevent spread |
|
cohort study |
(start with exposure) people without disease classified by exposure and monitored |
|
survival time |
time from diagnosis to death |
|
Hippocrates |
father of medicine (disease environment, not supernatural) |
|
James Lind |
considered atmospheric environment of sailors (scurvey) |
|
Koch |
determined diseases caused by living organisms |
|
William Farr |
compiler of statistics (foundation for the ICD) |
|
John Snow |
linked cholera with drinking water |
|
infectious diseases |
leading killers until late 19th century |
|
chronic diseases (long latency) |
increasing in recent years |
|
eco-epidemiology |
linking environment with human health |
|
measures of disease frequency |
ratio, count, proportion, percentage, rate |
|
rate (crude rate) |
cases / population at risk in time period (x100,000) |
|
incidence density |
new cases / person-time of observation |
|
birth rate |
live births / population (x1000) |
|
fertility rate |
live births / women 15-44 (x1000) |
|
infant mortality rate |
infant deaths / live births (x1000) |
|
maternal mortality rate |
deaths / live births (x100,000) |
|
person data |
collected by census (age, gender, race, education, occupation, income, marital status) |
|
place data |
international, national, regional, local |
|
time data |
seasonal fluctuations, time trends |
|
endemic rate |
usual rate of occurrence |
|
epidemic rate |
increase over endemic rate |
|
pandemic |
global epidemic |
|
latent period |
time between exposure and S&S |
|
migration studies |
study roles of genetics and environment |
|
Correlational studies (ecological studies) |
compare disease to factor of interest (in entire populations; quick and inexpensive) |
|
case report (case series) |
description of experiences of singe patient (or group of patients with similar diagnosis) |
|
3 agencies collecting data |
CIPHS, BCCDC, Health Status Registry |
|
SEER |
surveillance, epidemiology and end results (USA Cancer data) |
|
mortality rate |
incidence / mortality (% of incidence rate) |
|
ICD |
international classification of disease (WHO) |
|
underlying cause |
main cause (no death without it) |
|
3 limitations of death certificates |
little physician training, only 1 underlying cause of death, artificial changes in patterns with changes in classifications |
|
death among young people |
greater loss of life expectancy |
|
PYLL |
person years of life lost |
|
surveillance of risk factors |
characterize patterns of risk factor distribution (person, place, time) |
|
BRFSS |
behavioural risk factor surveillance system |