finals quiz 1

• What are the two main types of epidemiologic studies?

  Descriptive and Analytical
• What is the primary focus of descriptive studies?

  To describe characteristics of groups
• What is the primary focus of analytical studies?

  To analyze why a group has characteristics
• What does a descriptive study assume about hypotheses?

  Assumes no hypothesis
• What does an analytical study assume about hypotheses?

  Assumes hypothesis
• What is the purpose of a descriptive study?

  To identify non-random variation in disease occurrence
• What are common sources of data for descriptive studies?

  Routinely collected data
• What is one use of descriptive studies?

  Trend analysis to describe disease patterns
• What are the types of descriptive studies?

  1. Ecologic (correlational studies)
  2. Case Reports
  3. Case Series
• What do ecologic studies measure?

  Characteristics representing entire populations
• What is an example of an ecologic study?

  Mortality from lung cancer & cigarette sales
• What is a limitation of ecologic studies?

  Cannot link exposure with disease at individual level
• What is the primary analytical feature of ecologic studies?

  Comparison of groups rather than individuals
• What do case reports document?

  Unusual medical occurrences
• What is the purpose of case series?

  To identify the presence of an epidemic
• What is the objective of analytical studies?

  To test a hypothesis
• What distinguishes cross-sectional studies from descriptive studies?

  Presence of comparison groups
• What is a key step in conducting a cross-sectional study?

  Choose study population
• What is the formula for prevalence proportion?

  $\frac{a + c}{a + b + c + d} \times 100$
• What does a prevalence ratio greater than 1 indicate?

  Exposure is positively associated with disease
• What is the interpretation of a prevalence odds ratio of 1.32?

  Alcohol drinkers have higher odds of liver cancer
• What is a limitation of cohort studies?

  Difficult to establish temporal relationships
• What is the definition of a cohort in epidemiology?

  A group sharing a common experience
• What is the purpose of risk difference analysis?

  To determine new cases due to exposure
• What does a relative risk of 1.39 indicate?

  Higher risk of disease among exposed group
• What are the advantages and limitations of cohort studies?

  Advantages:

  • Resource-efficient
  • Generalizable
  • No loss to follow-up

  
  

  Limitations:

  • Difficult to establish causality
  • Selection and response bias
  • Lacks information on past exposure
• What is the formula for cumulative incidence?

  $\frac{a + c}{a + b + c + d} \times 100$
• What does a cumulative incidence of 4.35% indicate?

  5 per 100 population had bacteuria
• What is the interpretation of a 27.86% attributable risk?

  New cases occurred due to OC use
• What is the significance of a prevalence of disease being low?

  PR will be close to POR
• What is the difference between PR and POR when prevalence is high?

  PR is greater than POR
• What type of diseases is PR preferred over POR?

  Chronic diseases with long-lasting risk factors
• What is the relationship between PR and POR when prevalence is low?

  They will be close in value
• What is the interpretation of a prevalence odds ratio of 6.54?

  Higher odds of disease in exposed group
• What is the significance of a null value of PR?

  Indicates no association with disease
• What does a PR of 1.31 suggest?

  Direct association with liver cancer
• What is the interpretation of a prevalence of 3.41%?

  1. 41% of males had liver cancer
• What does a prevalence odds ratio of 1.32 indicate?

  Higher odds of liver cancer in drinkers
• What is the interpretation of a prevalence ratio of 5.54?

  Higher risk of disease in exposed group
• What does a prevalence of 11.90% indicate?


  11.90% of the population had the disease