WGU D221 – Healthcare Research and
Statistics Exam Questions With Correct
Answers (Verified Answers) Plus
Rationales| 2026/2027 Q&A | Instant
Download Pdf.
1. Which statement best describes the primary purpose of evidence-
based practice in healthcare?
A. To replace clinical judgment with statistical formulas
B. To ensure all healthcare decisions are based exclusively on research
studies
C. To integrate the best available evidence with clinical expertise and
patient preferences
D. To eliminate variation in patient care
Answer: C. To integrate the best available evidence with clinical
expertise and patient preferences
Rationale: Evidence-based practice combines three major components:
the best available research evidence, the clinician's professional
expertise, and the patient's values, preferences, and circumstances.
Research evidence informs decisions but does not replace clinical
judgment or individualized patient care.
, 2. A researcher wants to determine whether a new patient-
education program reduces hospital readmissions compared with
the existing education program. Which type of research question
is this?
A. Descriptive
B. Comparative
C. Exploratory
D. Historical
Answer: B. Comparative
Rationale: A comparative research question examines differences
between two or more groups, interventions, treatments, or conditions.
Here, the researcher is comparing readmission outcomes between
patients receiving the new education program and those receiving the
existing program.
3. Which characteristic is most important when evaluating the
reliability of a measurement instrument?
A. It produces consistent results when measuring the same
phenomenon
B. It always produces statistically significant findings
C. It has a large sample size
D. It eliminates all researcher bias
Answer: A. It produces consistent results when measuring the same
phenomenon
,Rationale: Reliability refers to the consistency or stability of a
measurement. A reliable instrument should produce similar results
when the same construct is measured under similar conditions.
Reliability does not necessarily mean that an instrument accurately
measures the intended construct; that concern relates to validity.
4. A researcher randomly assigns patients to either a new
medication or a placebo and then compares outcomes. What type
of study is this?
A. Case study
B. Cross-sectional study
C. Randomized controlled trial
D. Correlational study
Answer: C. Randomized controlled trial
Rationale: A randomized controlled trial (RCT) involves assigning
participants to intervention and control groups using randomization.
RCTs are particularly valuable for evaluating cause-and-effect
relationships because randomization helps balance potential
confounding variables between groups.
5. Which variable is considered a nominal-level variable?
A. Patient satisfaction rated from 1 to 10
B. Body temperature in degrees Celsius
C. Blood type
D. Number of hospital admissions
, Answer: C. Blood type
Rationale: Nominal variables classify observations into categories
without an inherent order or ranking. Blood type categories such as A,
B, AB, and O are nominal. Satisfaction ratings are typically ordinal,
temperature is commonly treated as an interval variable, and number of
admissions is a ratio variable.
6. A hospital researcher records the number of falls experienced by
each patient during hospitalization. What type of variable is the
number of falls?
A. Nominal
B. Ordinal
C. Continuous
D. Discrete
Answer: D. Discrete
Rationale: A discrete variable consists of countable values, usually
whole numbers. Patients can experience 0, 1, 2, or 3 falls, but not 1.5
falls. Therefore, the number of falls is a discrete quantitative variable.
7. Which measure of central tendency is most appropriate when a
dataset contains substantial outliers?
A. Mean
B. Median
C. Variance
D. Standard deviation
Statistics Exam Questions With Correct
Answers (Verified Answers) Plus
Rationales| 2026/2027 Q&A | Instant
Download Pdf.
1. Which statement best describes the primary purpose of evidence-
based practice in healthcare?
A. To replace clinical judgment with statistical formulas
B. To ensure all healthcare decisions are based exclusively on research
studies
C. To integrate the best available evidence with clinical expertise and
patient preferences
D. To eliminate variation in patient care
Answer: C. To integrate the best available evidence with clinical
expertise and patient preferences
Rationale: Evidence-based practice combines three major components:
the best available research evidence, the clinician's professional
expertise, and the patient's values, preferences, and circumstances.
Research evidence informs decisions but does not replace clinical
judgment or individualized patient care.
, 2. A researcher wants to determine whether a new patient-
education program reduces hospital readmissions compared with
the existing education program. Which type of research question
is this?
A. Descriptive
B. Comparative
C. Exploratory
D. Historical
Answer: B. Comparative
Rationale: A comparative research question examines differences
between two or more groups, interventions, treatments, or conditions.
Here, the researcher is comparing readmission outcomes between
patients receiving the new education program and those receiving the
existing program.
3. Which characteristic is most important when evaluating the
reliability of a measurement instrument?
A. It produces consistent results when measuring the same
phenomenon
B. It always produces statistically significant findings
C. It has a large sample size
D. It eliminates all researcher bias
Answer: A. It produces consistent results when measuring the same
phenomenon
,Rationale: Reliability refers to the consistency or stability of a
measurement. A reliable instrument should produce similar results
when the same construct is measured under similar conditions.
Reliability does not necessarily mean that an instrument accurately
measures the intended construct; that concern relates to validity.
4. A researcher randomly assigns patients to either a new
medication or a placebo and then compares outcomes. What type
of study is this?
A. Case study
B. Cross-sectional study
C. Randomized controlled trial
D. Correlational study
Answer: C. Randomized controlled trial
Rationale: A randomized controlled trial (RCT) involves assigning
participants to intervention and control groups using randomization.
RCTs are particularly valuable for evaluating cause-and-effect
relationships because randomization helps balance potential
confounding variables between groups.
5. Which variable is considered a nominal-level variable?
A. Patient satisfaction rated from 1 to 10
B. Body temperature in degrees Celsius
C. Blood type
D. Number of hospital admissions
, Answer: C. Blood type
Rationale: Nominal variables classify observations into categories
without an inherent order or ranking. Blood type categories such as A,
B, AB, and O are nominal. Satisfaction ratings are typically ordinal,
temperature is commonly treated as an interval variable, and number of
admissions is a ratio variable.
6. A hospital researcher records the number of falls experienced by
each patient during hospitalization. What type of variable is the
number of falls?
A. Nominal
B. Ordinal
C. Continuous
D. Discrete
Answer: D. Discrete
Rationale: A discrete variable consists of countable values, usually
whole numbers. Patients can experience 0, 1, 2, or 3 falls, but not 1.5
falls. Therefore, the number of falls is a discrete quantitative variable.
7. Which measure of central tendency is most appropriate when a
dataset contains substantial outliers?
A. Mean
B. Median
C. Variance
D. Standard deviation
