HLTH 501 Biostatistics Study
Guide t=with 100% correct
answers
Point prevalence (PP)
=number of persons with disease/number of persons examined at
baseline
Risk difference (RD)
=PPexposed-PPunexposed;
CIexposed-CIunexposed;
IRexposed-IRunexposed
Cumulative Incidence (CI)
=number of persons who develop disease during a specified
period/number of persons at risk at baseline
Population Attributable Risk (PAR)
=PPoverall-PPunexposed/PPoverall;
CIoverall-CIunexposed/CIoverall;
IRoverall-IRunexposed/IRoverall
Odds ratio (OR)
=PPexposed/(1-PPexposed)//PPunexposed/(1-PPunexposed);
CIexposed/(1-CIexposed)//CIunexposed/(1-CIunexposed)
relative risk (RR)
=PPexposed/PPunexposed;
CIexposed/CIunexposed
incidence rate (IR)
=number of persons who develop disease during a specified
period/sum of the length of time during which persons are disease
free
,Standard deviation (s)
mean (x)
median for odd
The best numerical summaries for dichotomous, ordinal, and
categorical variables are relative frequencies.
True
Two types of medical devices used for knee replacement are being
studied to see if the type of knee replacement used affects the rate
of infection for a specific bacterial infection. The infection rate for a
specific bacterial infection after surgery for device A is 0.0043. The
rate for the same bacterial infection is 0.0121 for device B. How
does the risk of developing the bacterial infection in individuals
using device B compare to the risk of developing the bacterial
infection in individuals using device A?
Individuals using device B are 2.814 times more likely to develop
the bacterial infection of interest than individuals using device A.
Confounding is usually a major issue in cohort studies.
True
The population attributable risk is usually expressed as a
percentage and ranges from 0% to 100%.
,True
The Cumulative incidence is computed as the number of persons
who develop a disease during a specified period over the number of
persons examined at baseline
False
A nested case-control study is a specific type of case-control study
that is usually designed from a cohort study.
True
A design that is a very detailed report of the specific features of a
particular participant or case is known as?
Case report
Calculate the mean blood glucose level for a study measuring the
blood glucose levels of 10 individuals whose blood glucose readings
were as follows: 88, 97, 101, 104, 104, 107, 109, 117, 121, and 147.
109.5
Which type of study design can assess temporal relationship?
A cohort study
In a study, some patients were not followed for a total of 10 years.
Some suffered events (i.e., developed coronary artery disease
during follow-up), whereas others dropped out of the study. The
following table displays the total number of person-years of follow-
up in each group.
Number with Coronary Artery Disease
Total Follow-Up (years)
High Blood Pressure medication
16
3200
Placebo
28
2750
The incidence rate of coronary artery disease in patients receiving
the new medication (High Blood Pressure medication) is
approximately:
, 5 per 1000 person-years
The applicability of the research results to a specific population
obtained from a biostatistics study is best determined by which of
the following?
The inclusion and exclusion criteria of the study
A study that is conducted at a single point in time is known as:
A cross-sectional study
The median of a group of individuals' BMIs whose BMIs are 20.47,
21.92, 23.32, 23.41, 25.7, and 30.1 is approximately 24.15.
False
The term clinical means that the study involves people.
True
The best measure of central tendency for systolic blood pressure
readings obtained from a population of 7 individuals whose systolic
blood pressure readings were 101, 104, 108, 109, 111, 112, and 160
is the mean.
False
1,000 people are enrolled in a 10-year cohort study. At the start of
the study, 100 have diagnosed CVD. Over the course of the study, 80
people who were free of CVD at baseline develop CVD. What is the
cumulative incidence at 10 years?
0.089
Incidence of disease is the proportion of individuals with the
condition (disease) at a single point in time
False
Clinical trials are regulated in the United States by the
Environmental Protection Agency.
False
The measure of uncertainty in a biostatistician's calculation of a
particular outcome that may result from using a subset of the
population to estimate the actual likelihood of the event occurring
in the population as a whole is referred to by what statistical term?
A margin of error
Guide t=with 100% correct
answers
Point prevalence (PP)
=number of persons with disease/number of persons examined at
baseline
Risk difference (RD)
=PPexposed-PPunexposed;
CIexposed-CIunexposed;
IRexposed-IRunexposed
Cumulative Incidence (CI)
=number of persons who develop disease during a specified
period/number of persons at risk at baseline
Population Attributable Risk (PAR)
=PPoverall-PPunexposed/PPoverall;
CIoverall-CIunexposed/CIoverall;
IRoverall-IRunexposed/IRoverall
Odds ratio (OR)
=PPexposed/(1-PPexposed)//PPunexposed/(1-PPunexposed);
CIexposed/(1-CIexposed)//CIunexposed/(1-CIunexposed)
relative risk (RR)
=PPexposed/PPunexposed;
CIexposed/CIunexposed
incidence rate (IR)
=number of persons who develop disease during a specified
period/sum of the length of time during which persons are disease
free
,Standard deviation (s)
mean (x)
median for odd
The best numerical summaries for dichotomous, ordinal, and
categorical variables are relative frequencies.
True
Two types of medical devices used for knee replacement are being
studied to see if the type of knee replacement used affects the rate
of infection for a specific bacterial infection. The infection rate for a
specific bacterial infection after surgery for device A is 0.0043. The
rate for the same bacterial infection is 0.0121 for device B. How
does the risk of developing the bacterial infection in individuals
using device B compare to the risk of developing the bacterial
infection in individuals using device A?
Individuals using device B are 2.814 times more likely to develop
the bacterial infection of interest than individuals using device A.
Confounding is usually a major issue in cohort studies.
True
The population attributable risk is usually expressed as a
percentage and ranges from 0% to 100%.
,True
The Cumulative incidence is computed as the number of persons
who develop a disease during a specified period over the number of
persons examined at baseline
False
A nested case-control study is a specific type of case-control study
that is usually designed from a cohort study.
True
A design that is a very detailed report of the specific features of a
particular participant or case is known as?
Case report
Calculate the mean blood glucose level for a study measuring the
blood glucose levels of 10 individuals whose blood glucose readings
were as follows: 88, 97, 101, 104, 104, 107, 109, 117, 121, and 147.
109.5
Which type of study design can assess temporal relationship?
A cohort study
In a study, some patients were not followed for a total of 10 years.
Some suffered events (i.e., developed coronary artery disease
during follow-up), whereas others dropped out of the study. The
following table displays the total number of person-years of follow-
up in each group.
Number with Coronary Artery Disease
Total Follow-Up (years)
High Blood Pressure medication
16
3200
Placebo
28
2750
The incidence rate of coronary artery disease in patients receiving
the new medication (High Blood Pressure medication) is
approximately:
, 5 per 1000 person-years
The applicability of the research results to a specific population
obtained from a biostatistics study is best determined by which of
the following?
The inclusion and exclusion criteria of the study
A study that is conducted at a single point in time is known as:
A cross-sectional study
The median of a group of individuals' BMIs whose BMIs are 20.47,
21.92, 23.32, 23.41, 25.7, and 30.1 is approximately 24.15.
False
The term clinical means that the study involves people.
True
The best measure of central tendency for systolic blood pressure
readings obtained from a population of 7 individuals whose systolic
blood pressure readings were 101, 104, 108, 109, 111, 112, and 160
is the mean.
False
1,000 people are enrolled in a 10-year cohort study. At the start of
the study, 100 have diagnosed CVD. Over the course of the study, 80
people who were free of CVD at baseline develop CVD. What is the
cumulative incidence at 10 years?
0.089
Incidence of disease is the proportion of individuals with the
condition (disease) at a single point in time
False
Clinical trials are regulated in the United States by the
Environmental Protection Agency.
False
The measure of uncertainty in a biostatistician's calculation of a
particular outcome that may result from using a subset of the
population to estimate the actual likelihood of the event occurring
in the population as a whole is referred to by what statistical term?
A margin of error
