Epidemiology key terms measures
Download
1 / 25

Epidemiology Key Terms & Measures - PowerPoint PPT Presentation


  • 98 Views
  • Updated On :

Epidemiology Key Terms & Measures. Fran C. Wheeler, Ph.D School of Public Health University of South Carolina Columbia, SC 29208 (803) 777-5054 [email protected]

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Epidemiology Key Terms & Measures' - zack


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Epidemiology key terms measures
EpidemiologyKey Terms & Measures

Fran C. Wheeler, Ph.D

School of Public Health

University of South Carolina

Columbia, SC 29208

(803) 777-5054

[email protected]


Developed as part of an Enhanced AHEC Community Partnership for Health Professions Workforce and Educational Reform project funded by the Health Resource and Service Administration (HRSA)


Objectives
OBJECTIVES for Health Professions Workforce and Educational Reform project funded by the Health Resource and Service Administration (HRSA)

  • epidemiology and role as foundation for public health

  • common measures of disease frequency

  • strengths and weaknesses of study designs


Epidemiology
Epidemiology for Health Professions Workforce and Educational Reform project funded by the Health Resource and Service Administration (HRSA)

  • Study of distribution of determinants and antecedents of health and disease in human populations

  • Application of results to control of health problems


From hippocrates to john graunt
From Hippocrates for Health Professions Workforce and Educational Reform project funded by the Health Resource and Service Administration (HRSA) to John Graunt

  • Fifth century BCE, Hippocrates pointed to the need to understand the environment and the risks it posed to understand the experience of disease

  • 1662, John Graunt analyzed weekly reports of births and deaths in London, quantifying patterns of disease in the population


From william farr to john snow
From William Farr for Health Professions Workforce and Educational Reform project funded by the Health Resource and Service Administration (HRSA) to John Snow

  • 200 years later, Dr. William Farr was made responsible for medical statistics in the Office of the Registrar General for England and Wales

  • A mere 20 years later, John Snow completed his study of cholera


Modern experiences
Modern Experiences for Health Professions Workforce and Educational Reform project funded by the Health Resource and Service Administration (HRSA)

  • Evaluation of risk factors for chronic diseases using case controls

  • Long term population studies using cohorts

  • Design of clinical trials to evaluate interventions


Three essential components

Expected level for Health Professions Workforce and Educational Reform project funded by the Health Resource and Service Administration (HRSA)

Endemic

Sporadic

Epidemic

Pandemic

Three Essential Components

  • Disease distribution

  • Disease determinants

  • Disease frequency


Epidemiologic studies
Epidemiologic Studies for Health Professions Workforce and Educational Reform project funded by the Health Resource and Service Administration (HRSA)

  • Descriptive

  • Analytic


Descriptive studies
Descriptive Studies for Health Professions Workforce and Educational Reform project funded by the Health Resource and Service Administration (HRSA)

  • Frequency of occurrence of particular condition

  • Patterns of occurrence according to person, place and time


Analytic studies
Analytic Studies for Health Professions Workforce and Educational Reform project funded by the Health Resource and Service Administration (HRSA)

  • Observational studies

    • case-control studies

    • cohort studies

      • prospective

      • retrospective

  • Experimental studies


Case control study
Case Control Study for Health Professions Workforce and Educational Reform project funded by the Health Resource and Service Administration (HRSA)

Exposure

Disease

?

?

Key

Basis for selection of group for study

= present = absent


Prospective cohort study
Prospective Cohort Study for Health Professions Workforce and Educational Reform project funded by the Health Resource and Service Administration (HRSA)

Exposure

Disease

?

?

Key

Basis for selection of group for study

= present = absent


Retrospective cohort study
Retrospective Cohort Study for Health Professions Workforce and Educational Reform project funded by the Health Resource and Service Administration (HRSA)

Exposure

Disease

?

?

Key

Basis of selection of group for study

= present = absent


Analytic studies1
Analytic Studies for Health Professions Workforce and Educational Reform project funded by the Health Resource and Service Administration (HRSA)

  • Observational studies

  • Experimental studies

    • Intervention studies

    • Clinical trials


Basic presentation of results
Basic Presentation of Results for Health Professions Workforce and Educational Reform project funded by the Health Resource and Service Administration (HRSA)

All rates and ratios discussed can be calculated from this


Smoking and carcinoma of the lung
Smoking for Health Professions Workforce and Educational Reform project funded by the Health Resource and Service Administration (HRSA) and Carcinoma of the Lung


Interpreting results measurement errors

Bias for Health Professions Workforce and Educational Reform project funded by the Health Resource and Service Administration (HRSA)

information

selection

Confounding

extraneous factors

Effect modification

statistical interaction

Interpreting Results: Measurement Errors


Interpreting results cause effect relationship

Strength of the association for Health Professions Workforce and Educational Reform project funded by the Health Resource and Service Administration (HRSA)

Consistency

Temporality

Plausibility

Biological gradient

Interpreting Results: Cause-Effect Relationship


Measures of disease frequency
Measures of Disease Frequency for Health Professions Workforce and Educational Reform project funded by the Health Resource and Service Administration (HRSA)

  • Prevalence

  • Incidence


Prevalence

Prevalence= number of existing cases divided by total population

Visual examination survey

310 X 100 = 12.5%

2477

Prevalence



Incidence
Incidence population

  • Incidence = number of new cases in a given period of time divided by the total population at risk

    • Bacteremia among contraceptive users

      • 27/483 X 100 = 5.6%



Rates commonly used in epidemiology

Crude population

Category specific

Age adjusted

Rates Commonly Used in Epidemiology


ad