Intro to epidemiology Flashcards
what is epidemiology
-emphasizes increase inquiry of disease states and events in an objective, scientific, and controlled manner
-Screening, utilizing interventions, and preventing bad health outcomes in the community
-Good health outcomes decreases morbidity and mortality in the population; increases life expectancy, quality of life, economic efficiency, and positive social changes
-The study of the prevalence and incidence of disease frequency in human populations and the application of this study to control health problems
human population
-group of people with common characteristic such as residence, age, gender
prevalence
-how is disease distributed throughout population
-person- age, sex
-place- urban, US states, near incinerator
-time- june, annual, decade
-The proportion of persons within a population who have the condition of interest is referred to as prevalence.
epidemiology is based on 2 fundamental assumptions
-1. Human disease does not occur at random; there are factors which can increase or decrease the likelihood of disease
-2) The factors can be identified by systematic investigation of populations or subgroups within populations
incidence rate
measures the rapidity with which newly diagnosed cases of a disease develop
types of prevalence
-Point prevalence: the number of cases at a specific point in time.
-Period prevalence: the number of cases over a defined period.
-Lifetime prevalence: the proportion of individuals who have been affected by a disorder at any time during their lives
current issues in epidemiology
-Vaping
-Drug abuse (opiates, alcohol)
-Air quality
-Firearms
-Mental health Issues
-PTSD
-Social Media
-Caretaker fatigue
-Obesity
sample
subgroup of the whole affected population (all patients with flu in Old Westbury as opposed to all of New York State)
mean
average; obtained by adding up all the numbers and dividing by the total (N) of numbers
median
center number in the ordered sequence of data points
mode
the number which occurs most often in a sequence
Ex: 2, 3, 5, 9, 10, 11, 12, 14, 28, 28, 34, 54, 88
sampling error
natural variability, not caused on purpose. Ex-If conducting a study on capacity of school buses for middle school-not all 4-6 graders weigh the same or have similar height. Can be mitigated by increasing sample size. (unbiased)
selection bias
the sample was not chosen randomly for the study, but the researcher inadvertently had a bias. Ex-a researcher has more female patients in the group receiving a promising medication because they reminded him of his mother who was ill
validity
the accuracy of a test. The test measures accurately the information sought by the researcher.
reliability
repeated administration of the test leads to the same result
independent variable
the one that influences the change (the one being manipulated). Usually graphed on the horizontal axis
-The independent variable causes a change in the dependent variable
dependent variable
is the result of applying the independent variable (the one being studied). Usually graphed on the vertical axis
range
-difference between highest and lowest value
standard deviation
the spread of the data being observed. The range in a normal bell curve: 1 standard deviation 68%, 2 SD 95%, 3 SD 99%
nominal data
categories in name only (blood type, eye color), has no particular order
ordinal data
has a particular order (pain scale from 1-5)
interval data
clear order, data points which will have a mean, mode, or median, can lead to more precise measurements
statistical significance
a result which is less likely due to chance. However, it does not mean it is clinically significant
sub-discipline of epidemiology
-disease- cancer, cardo, infectious
-exposure- environmental, genetic, nutrition
-population- clinical, geriatric, pregnant
epidemiology helps answer questions
-Is the rate of drunk driving accidents increasing?
-What was the cause of the hepatitis outbreak?
-Who is most likely to get the flu?
-Do cell phones cause brain tumors?
-Is echinacea effective in treating the common cold?
-Are cardiac rehabilitation programs worthwhile?
-Does tamoxifen prevent breast cancer in women at high risk?
-Does vaccination cause seizures?
-Do certain genes put people at higher risk for diabetes
sequence of epidemiologic investigations
-suspect exposure influences disease occurrence
-form specific hypothesis about exposure disease assoc
-conduct epidemiologic study to measure relationship
-judge whether assoc is valid and causal, considering -> accumulated evidence, chance, bias, confounding, + and - of study design
-eval preventions and tx
hypothesis
-A testable statement that tries to explain a set of observations and can be tentatively rejected (or not rejected) through scientific research
-2 criteria:
-1. Hypotheses are statements that project the expected association between two or more measurable variables
-2. Hypotheses carry clear implications for testing stated relations
hypotheses are important for
-Advancing epidemiologic research
-Guiding study design, variable selection, sample selection, data analyses, and interpretation of results
null hypothesis
-ex. vaping does not cause seizures
-null hypothesis is a statement saying there is no relationship
-there is no relationship between vaping and seizures
-there is no significant difference
alternative hypothesis
-there is a significant difference
-ex. vaping does cause seizures
-there is a relationship
