EBPP Sem 2 EPIDEMIOLOGY 2024/2025
Exam Questions Marking Scheme New
Update | A+ Rated
epidemiology - 🧠ANSWER ✔✔study of how often diseases occur in different
groups of people and why
two main questions in medicine - 🧠ANSWER ✔✔what causes a disease
how can we best treat a disease
three ways cases can be defined - 🧠ANSWER ✔✔statistical
operational
clinical
distinguish between statistical, operational, and clinical definitions of cases -
🧠ANSWER ✔✔statistical - perhaps someone who has a certain number of
standard deviations above the mean
operational - e.g. dividing myopia into high and low myopia
clinical- this definition will choose a criterion
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,major dividing line of study designs in epidemiology - 🧠ANSWER ✔✔major
dividing line is between:
observational studies or medical surveys (those which just measure level of
disease or condition, identify factors regarded as causal in the development of a
disease (risk factors), etc.)
intervention studies or experimental studies (those which test a new treatment
to see if it is effective.)
cross sectional studies - 🧠ANSWER ✔✔looks at health in a specific moment in
time
crude prevalence ratio - 🧠ANSWER ✔✔the number of cases divided by the size
of the population
specific prevalence ratio - 🧠ANSWER ✔✔prevalence in a sub population
prevalence v odds
e.g.
age 80-84 cataract 37, no cataract 40, total 77 - 🧠ANSWER ✔✔prevalence is
number w disease/total
odds is number w disease/ number without
Page 2 of 18
COPYRIGHT©JOSHCLAY 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER:
619652435. TERMS OF USE. PRIVACY STATEMENT. ALL RIGHTS RESERVED
, prevalence of cataract 37/77
odds of cataract is 37/40
what can odds ratio be used as a measure of - 🧠ANSWER ✔✔association
positive association and negative association odds ratio value - 🧠ANSWER
✔✔positive association between risk factor and disease - odds ratio greater
than one
negative association between risk factor and disease- odds ratio less than one
cohens rule of thumb for size of odds ratio and interpretation - 🧠ANSWER
✔✔+ve assosciation
1-1.45 small
around 3.5 medium
around 10 large
-ve association
0.69-1 small
around 0.3 medium
around 0.1 larger
Page 3 of 18
COPYRIGHT©JOSHCLAY 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER:
619652435. TERMS OF USE. PRIVACY STATEMENT. ALL RIGHTS RESERVED
Exam Questions Marking Scheme New
Update | A+ Rated
epidemiology - 🧠ANSWER ✔✔study of how often diseases occur in different
groups of people and why
two main questions in medicine - 🧠ANSWER ✔✔what causes a disease
how can we best treat a disease
three ways cases can be defined - 🧠ANSWER ✔✔statistical
operational
clinical
distinguish between statistical, operational, and clinical definitions of cases -
🧠ANSWER ✔✔statistical - perhaps someone who has a certain number of
standard deviations above the mean
operational - e.g. dividing myopia into high and low myopia
clinical- this definition will choose a criterion
Page 1 of 18
COPYRIGHT©JOSHCLAY 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER:
619652435. TERMS OF USE. PRIVACY STATEMENT. ALL RIGHTS RESERVED
,major dividing line of study designs in epidemiology - 🧠ANSWER ✔✔major
dividing line is between:
observational studies or medical surveys (those which just measure level of
disease or condition, identify factors regarded as causal in the development of a
disease (risk factors), etc.)
intervention studies or experimental studies (those which test a new treatment
to see if it is effective.)
cross sectional studies - 🧠ANSWER ✔✔looks at health in a specific moment in
time
crude prevalence ratio - 🧠ANSWER ✔✔the number of cases divided by the size
of the population
specific prevalence ratio - 🧠ANSWER ✔✔prevalence in a sub population
prevalence v odds
e.g.
age 80-84 cataract 37, no cataract 40, total 77 - 🧠ANSWER ✔✔prevalence is
number w disease/total
odds is number w disease/ number without
Page 2 of 18
COPYRIGHT©JOSHCLAY 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER:
619652435. TERMS OF USE. PRIVACY STATEMENT. ALL RIGHTS RESERVED
, prevalence of cataract 37/77
odds of cataract is 37/40
what can odds ratio be used as a measure of - 🧠ANSWER ✔✔association
positive association and negative association odds ratio value - 🧠ANSWER
✔✔positive association between risk factor and disease - odds ratio greater
than one
negative association between risk factor and disease- odds ratio less than one
cohens rule of thumb for size of odds ratio and interpretation - 🧠ANSWER
✔✔+ve assosciation
1-1.45 small
around 3.5 medium
around 10 large
-ve association
0.69-1 small
around 0.3 medium
around 0.1 larger
Page 3 of 18
COPYRIGHT©JOSHCLAY 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER:
619652435. TERMS OF USE. PRIVACY STATEMENT. ALL RIGHTS RESERVED
