HLTH 501 BIOSTATISTICS PRACTICE EXAM
2026 QUESTIONS WITH ACCURATE ANSWERS
◉ True or False? The wash-out period is included in a crossover trial
so that any therapeutic effects of the first treatment are removed,
prior to the administration of the second treatment. Answer: True
◉ A novice researcher noted that during summertime there is a
positive association between the increase in ice cream sales and the
increase in the number of drownings; however, there is no logical
explanation for why ice cream sales would be responsible for the
increased incidence of drowning. What phenomenon likely explains
this type of observation? Answer: Confounding
◉ A number of patients have been admitted to a particular hospital
with similar symptoms and the cause of the illness is unknown.
Which type of study design would be most helpful in determining
the cause of the illness? Answer: A case series
◉ True or False? An active-control trial is the best option for
researchers hoping to test a newly devised therapy for a life-
threatening illness among individuals with the illness, when a
previously devised treatment is available for the illness. Answer:
True
,◉ The minimization of bias and confounding in clinical trials is
obtained through the use of which of the following? Answer:
Randomization of study participants to make groups comparable in
all respects
◉ True or False? The public health department in a particular
county with 157,237 residents has documented 629 cases of HIV;
157 individuals were diagnosed in the past year. Thus, the
cumulative incidence for HIV in this particular county is
approximately 0.1. Answer: False
◉ True or False? An absolute difference calculation is ideal when
calculating the risk difference between two categorical variables.
Answer: True
◉ Longitudinal cohort studies that produce data measured in
person-time are particularly subject to which of the following forms
of statistical anomaly? Answer: Type one censoring
◉ Assuming 320,000 individuals develop Lyme disease each year,
what is the attributable risk for the cumulative incidence of Lyme
disease that comes from tick bites, if 300,000 of the new cases
reported each year come from tick bites? Answer: 93.75%
◉ True or False? Relative risk is an ideal form of measurement for a
retrospective study design because it allows researchers to recruit
, both individuals with the outcome of interest and individuals
without the outcome of interest, then match individuals from each of
the respective groups to individuals of the other group in order to
determine if a specific exposure caused the outcome of interest.
Answer: False
◉ True or False? A group of 250 women over the age of 40 are
recruited for a study to determine the effects that calcium has on
bone health. Half of the participants are given a calcium supplement
and the other half are given a placebo. If 13 women on calcium
develop osteomalacia and 27 women on the placebo develop
osteomalacia, the relative risk for developing osteomalacia for
women over 40 on a calcium supplement is 0.48 when compared to
those women not taking a calcium supplement. This indicates that
taking calcium has no effect on the population of interest's health
because the relative risk is less than 1.0. Answer: False
◉ A disease that has a low prevalence but high incidence rate is best
described as which of the following types of diseases? Answer: A
contagious acute illness
◉ Which statistical property make odds ratios the ideal
measurement for case-control studies? Answer: Its insensitivity to
variance
2026 QUESTIONS WITH ACCURATE ANSWERS
◉ True or False? The wash-out period is included in a crossover trial
so that any therapeutic effects of the first treatment are removed,
prior to the administration of the second treatment. Answer: True
◉ A novice researcher noted that during summertime there is a
positive association between the increase in ice cream sales and the
increase in the number of drownings; however, there is no logical
explanation for why ice cream sales would be responsible for the
increased incidence of drowning. What phenomenon likely explains
this type of observation? Answer: Confounding
◉ A number of patients have been admitted to a particular hospital
with similar symptoms and the cause of the illness is unknown.
Which type of study design would be most helpful in determining
the cause of the illness? Answer: A case series
◉ True or False? An active-control trial is the best option for
researchers hoping to test a newly devised therapy for a life-
threatening illness among individuals with the illness, when a
previously devised treatment is available for the illness. Answer:
True
,◉ The minimization of bias and confounding in clinical trials is
obtained through the use of which of the following? Answer:
Randomization of study participants to make groups comparable in
all respects
◉ True or False? The public health department in a particular
county with 157,237 residents has documented 629 cases of HIV;
157 individuals were diagnosed in the past year. Thus, the
cumulative incidence for HIV in this particular county is
approximately 0.1. Answer: False
◉ True or False? An absolute difference calculation is ideal when
calculating the risk difference between two categorical variables.
Answer: True
◉ Longitudinal cohort studies that produce data measured in
person-time are particularly subject to which of the following forms
of statistical anomaly? Answer: Type one censoring
◉ Assuming 320,000 individuals develop Lyme disease each year,
what is the attributable risk for the cumulative incidence of Lyme
disease that comes from tick bites, if 300,000 of the new cases
reported each year come from tick bites? Answer: 93.75%
◉ True or False? Relative risk is an ideal form of measurement for a
retrospective study design because it allows researchers to recruit
, both individuals with the outcome of interest and individuals
without the outcome of interest, then match individuals from each of
the respective groups to individuals of the other group in order to
determine if a specific exposure caused the outcome of interest.
Answer: False
◉ True or False? A group of 250 women over the age of 40 are
recruited for a study to determine the effects that calcium has on
bone health. Half of the participants are given a calcium supplement
and the other half are given a placebo. If 13 women on calcium
develop osteomalacia and 27 women on the placebo develop
osteomalacia, the relative risk for developing osteomalacia for
women over 40 on a calcium supplement is 0.48 when compared to
those women not taking a calcium supplement. This indicates that
taking calcium has no effect on the population of interest's health
because the relative risk is less than 1.0. Answer: False
◉ A disease that has a low prevalence but high incidence rate is best
described as which of the following types of diseases? Answer: A
contagious acute illness
◉ Which statistical property make odds ratios the ideal
measurement for case-control studies? Answer: Its insensitivity to
variance
