Midterm Review Flashcards
of new cases of disease during a specified time interval {divided by} Population at risk at the start of the time interval
Incidence proption
What are synonyms for incidence proportion?
Attack rate, risk, probability of developing disease, cumulative incidence
of new cases among contacts {divided by} (total number of contacts)
secondary attack rate
of new cases of disease during a specified time interval {divided by} time each person was observed summed together
Incidence rate, aka person-time rate
of current cases at a certain point in time/total population at the time
point prevalence
of current cases at a certain point in time/ avg population
period prevalence
total # of deaths during a given time interval/mid-interval population
crude death rate, aka crude mortality rate
of deaths assigned to a specific cause during a given time interval/ avg population
cause-specific mortality rate
of deaths assigned to a specific cause during a certain time interval {divided by} the total # of deaths from all causes in the same time frame
proportionate mortality
of deaths assigned to a specific cause during a given time interval {divided by} # of new cases of same disease during that time
Death-to-case ratio
of deaths among children <28 days old in a certain time interval {divided by} # of live births in that time
neonatal mortality rate
of deaths among children 28-364 days old during a certain time interval {divided by} # of live births during that same time
postneonatal mortality rate
of deaths among children < 1 year during a given time interval / # of live births during that time
infant mortality rate
of deaths assigned to pregnancy-related causes during a given time interval / # of live births during that time
maternal mortality rate
of deaths in a particular age group / total # of people in the age group
age-specific mortality rate
of deaths males OR females / total # of males OR females
sex-specific mortality rate
of people infected / # of people exposed
infectivity
of people who develop clinically apparent disease / # of people infected
pathogenicity
of people who die / # of people who develop clinically apparent disease
virulence
(# case in exposed/total # exposed) - (#cases unexposed/total # unexposed)
Attributable Risk % (AKA attributable risk reduction ARR)
of events in control group/total # of control participants
Control Group Rate/Risk (CGR)
of events in experimental group/total # of experimental participants
Experimental Group Rate/Risk (EGR)
Control Group Rate (CGR) - Experimental Group Rate (EGR)
Attributable Risk Reduction
EGR/CGR
Relative Risk
1) (CGR-EGR)/CGR
2) 1-(EGR/CGR)
3) 1-RR
*Note: all 3 formulas should give you the same result
Relative Risk Reduction (RRR)
The study of the distribution and determinants of health-related states or events in specified populations and the application of this study to control of health problems
Epidemiology
The cause of a disease
Etiology
Action taken to prevent the development of a disease in people who do not have the disease Examples: Vaccines, healthy behaviors, etc.
Primary Prevention
Identifying people in whom a disease process has already begun but who have not yet developed clinical signs or symptoms of the disease (preclinical phase) Examples: Cancer screening, mammograms, etc.
Secondary Prevention
Preventing complications in those who have already developed signs and symptoms of an illness and have been diagnosed (those in the clinical phase of illness) Examples: Cancer treatment, physical therapy, etc.
Tertiary Prevention
form of disease characterized by signs and symptoms
Clinical disease
Signs and symptoms have not developed. Includes preclinical, subclinical, persistent, and latent disease.
Nonclinical (inapparent) disease
Disease is not clinically apparent but is destined to progress to clinical disease
Preclinical disease
Disease is not clinically apparent and is not destined to become clinically apparent. Diagnosed by serologic response or culture of the organism
Subclinical disease
The habitual presence of a disease within a given geographic area
Endemic
The occurrence in a community or region of a group of illnesses of similar nature, clearly in excess of normal expectancy and derived from a common or a propagated source
Epidemic
type of exposure where cases arise from the same exposure; Example: food poisoning outbreak from bad chicken at a buffet
Common-vehicle exposure
The resistance of a group of people to an attack by a disease to which a large proportion of the members of the group are immune
Herd immunity
The interval from infection to the time of onset of clinical illness. Often measured as the time from exposure until the onset of clinical disease as it is difficult to determine the exact time of infection.
Incubation period
A graph used to characterized the two primary types of outbreaks (common source and propagated). The y-axis is the number of cases and the x-axis is the date of onset each case patient. Note not all epidemics are common source or propagated- for example with some zoonotic or vector borne diseases.
Epidemic curve
The ongoing systematic collection, analysis, and interpretation of health data essential to the planning, implementation, and evaluation of public health practice closely integrated with the timely dissemination of these data to those who need to know
Epidemiologic surveillance
Surveillance in which available data on reportable disease are used, or in which disease reporting is mandated or requested by the government or the local health authority, with the responsibility for the reporting often falling on the health care provider or district health officer. Provider initiated; less resource intensive. Also known as ‘passive reporting’
Passive surveillance
Who initiates passive surveillance?
providers
A system in which staff are specifically contact providers or others to carry out a surveillance program. Often more accurate than passive. Health-department initiated; more resource intensive
Active surveillance
Who initiates active surveillance?
Health departments
Incidence calculated using a period of time during which all of the individuals in the population are considered to be at risk for the outcome.
Cumulative incidence proportion
The sum of the units of time that each individual was at risk and was observed. Often expressed in person-months or person-years.
Person-time
The number of affected persons present in the population at a specific time divided by the number of persons in the population at that time, aka proportion of the population is affected by the disease at that time
Prevalence
Percentage of people who have a certain disease die within a certain time after the disease was diagnosed
Case fatality
A standard population is used in order to eliminate the effects of any differences in age between two or more populations being compared. Most commonly used method.
Direct age adjustment
Used when numbers of deaths for each age-specific stratum are not available or in an occupationally exposed population.
Indirect age adjustment
Changes seen are attributable to the characteristics of the particular ‘cohort’ under study, not the variable being studied.
Cohort effect
Any empirical observation, whether systematically collected or not.
Evidence
A theory of knowledge that holds that the justification or reason of a belief is determined by the quality of the believer’s evidence for the belief
Evidentialism
System of rating the quality of evidence and strength of recommendations that is explicit, comprehensive, and increasingly adopted by guideline organizations. Four levels (very low-high).
GRADE (Grading of Recommendations Assessment, development, and Evaluation)
These clinical questions are about physiology, pathology, epidemiology, and general management and are often asked by clinicians in training. The answers to background questions are often best found in textbooks or narrative review articles.
Background questions
These clinical questions are more commonly asked by seasoned clinicians. They are questions asked when browsing the literature (e.g., what important new information should I know to optimally treat my patients?) or when problem solving (e.g., defining specific questions raised in caring for patients and then consulting the literature to resolve these problems)
Foreground questions
Patient, Intervention, Comparison, Outcome. A method for answering clinical questions
PICO framework
Determining the effect of interventions on patient-important outcomes (symptoms, function, morbidity, mortality, and costs)
Therapy (foreground clinical questions)
Ascertaining the effects of potentially harmful agents (including therapies from the first type of question) on patient-important outcomes
Harm (foreground clinical questions)
In patients with a particular clinical presentation, establishing the frequency of the underlying disorders
Differential diagnosis (foreground clinical questions)
Establishing the power of a test to differentiate between those with and without a target condition or disease
Diagnosis (foreground clinical questions)
includes many study designs that are not randomized such as cohort or case control studies where the exposure to the intervention or disease is not controlled by the researcher
Observational studies
A method having established or widely accepted accuracy for determining a diagnosis that provides a standard to which a new screening or diagnostic test can be compared
Reference standard/Criterion Standard
The extent to which study results are subject to systematic error.
Risk of bias
