ATI Evidence-
Based Practice:
Advanced
Comprehensive
Examination Version 3.1 -
Expert-Level Multiple-Choice Questions for
Advanced Practice Nurses and Doctoral-Level
Candidates well written one year 2025 /2026
updated graded A+
,SECTION A: ADVANCED RESEARCH METHODOLOGIES AND EVIDENCE
SYNTHESIS (Questions 1-25)
1. A nurse researcher is conducting a systematic review and meta-analysis examining the
effectiveness of nurse-led interventions in reducing hospital readmissions. The
researcher notes significant statistical heterogeneity (I² = 82%) among the included
studies. Which of the following approaches would be most appropriate for addressing
this heterogeneity while maintaining the integrity of the meta-analysis?
A) Exclude all studies with small sample sizes to reduce heterogeneity
B) Use a random-effects model and conduct subgroup analyses to explore sources
ofheterogeneity
C) Combine all studies using a fixed-effects model regardless of heterogeneity
D) Abandon the meta-analysis and conduct a narrative synthesis only
- detailed answer 100 % correct :-B
Rationale: When substantial heterogeneity exists, a random-effects model should be used
because it accounts for between-study variance. Subgroup analyses or meta-regression can
explore sources of heterogeneity. Excluding studies arbitrarily is inappropriate, and fixedeffects
models are not suitable when heterogeneity is significant.
2. A nurse is appraising a study that used a stepped-wedge cluster randomized trial
design to evaluate the implementation of an evidence-based early warning system in
multiple hospitals. Which of the following represents a critical limitation of this design
that could compromise internal validity?
A) Limited statistical power due to small sample size
B) Inability to account for secular trends or temporal confounding
C) The potential for contamination between intervention and control periods
D) Difficulty in obtaining ethical approval for cluster randomization
,- detailed answer 100 % correct :-C
Rationale: In stepped-wedge designs, all clusters eventually receive the intervention in a
phased manner, which can lead to contamination if control clusters are exposed to the
intervention practices before their designated time. While secular trends are a concern and can
be accounted for in the analysis, contamination represents a unique threat to internal validity
that is more difficult to control.
3. A nurse researcher is evaluating the quality of evidence using the GRADE (Grading of
Recommendations Assessment, Development and Evaluation) approach. The initial
highquality rating for randomized controlled trials can be downgraded for which of the
following reasons?
A) Large effect size and dose-response gradient
B) Risk of bias, inconsistency, indirectness, imprecision, and publication bias
C) Strong confounding and effect modification
D) High external validity and generalizability
- detailed answer 100 % correct :-B
Rationale: Under the GRADE approach, RCTs are initially rated as high-quality evidence but
can be downgraded based on five domains: risk of bias, inconsistency (heterogeneity),
indirectness (applicability), imprecision (wide confidence intervals), and publication bias.
Conversely, evidence can be upgraded based on large effect size, dose-response gradient, and
plausible confounding.
4. A nurse is conducting a meta-analysis and is deciding between using a fixed-effects
model versus a random-effects model. Which of the following best describes the key
difference in the assumptions underlying these two models?
A) Fixed-effects models assume the true effect size is identical across all studies, while
random-effects models assume the true effect size varies
B) Fixed-effects models produce wider confidence intervals than random-effects
modelsC) Random-effects models give more weight to smaller studies compared to fixed-
effects models
, D) Fixed-effects models can only be used when heterogeneity is greater than 50%
- detailed answer 100 % correct :-A
Rationale: The fundamental difference is the assumption about the underlying true effect size.
Fixed-effects models assume a single, common true effect across all studies (any variation is
due to sampling error). Random-effects models assume that the true effect size varies across
studies due to differences in study populations, interventions, or other factors.
5. A nurse researcher is performing a network meta-analysis comparing multiple
interventions for pain management. Which of the following represents a critical
assumption of network meta-analysis that must be satisfied for valid inference?
A) All studies included in the network must have the same sample size
B) The consistency assumption, meaning that direct and indirect evidence are in agreement
C) All interventions must be compared against placebo
D) Studies must be published within the last five years
- detailed answer 100 % correct :-B
Rationale: The consistency (or transitivity) assumption in network meta-analysis requires that
direct and indirect evidence are consistent with each other. If direct comparisons between two
interventions conflict with indirect comparisons through a third intervention, the results of the
network meta-analysis may be invalid.
6. A nurse is appraising a study that used a regression discontinuity design to evaluate
the impact of a new nurse staffing policy on patient outcomes. In this design, the key
feature that supports causal inference is:
A) Random assignment of hospitals to the intervention
B) Comparison of outcomes for units just above and below the staffing ratio threshold
C) Matching hospitals on key characteristics
D) Using instrumental variables to control for confounding
- detailed answer 100 % correct :-B
Based Practice:
Advanced
Comprehensive
Examination Version 3.1 -
Expert-Level Multiple-Choice Questions for
Advanced Practice Nurses and Doctoral-Level
Candidates well written one year 2025 /2026
updated graded A+
,SECTION A: ADVANCED RESEARCH METHODOLOGIES AND EVIDENCE
SYNTHESIS (Questions 1-25)
1. A nurse researcher is conducting a systematic review and meta-analysis examining the
effectiveness of nurse-led interventions in reducing hospital readmissions. The
researcher notes significant statistical heterogeneity (I² = 82%) among the included
studies. Which of the following approaches would be most appropriate for addressing
this heterogeneity while maintaining the integrity of the meta-analysis?
A) Exclude all studies with small sample sizes to reduce heterogeneity
B) Use a random-effects model and conduct subgroup analyses to explore sources
ofheterogeneity
C) Combine all studies using a fixed-effects model regardless of heterogeneity
D) Abandon the meta-analysis and conduct a narrative synthesis only
- detailed answer 100 % correct :-B
Rationale: When substantial heterogeneity exists, a random-effects model should be used
because it accounts for between-study variance. Subgroup analyses or meta-regression can
explore sources of heterogeneity. Excluding studies arbitrarily is inappropriate, and fixedeffects
models are not suitable when heterogeneity is significant.
2. A nurse is appraising a study that used a stepped-wedge cluster randomized trial
design to evaluate the implementation of an evidence-based early warning system in
multiple hospitals. Which of the following represents a critical limitation of this design
that could compromise internal validity?
A) Limited statistical power due to small sample size
B) Inability to account for secular trends or temporal confounding
C) The potential for contamination between intervention and control periods
D) Difficulty in obtaining ethical approval for cluster randomization
,- detailed answer 100 % correct :-C
Rationale: In stepped-wedge designs, all clusters eventually receive the intervention in a
phased manner, which can lead to contamination if control clusters are exposed to the
intervention practices before their designated time. While secular trends are a concern and can
be accounted for in the analysis, contamination represents a unique threat to internal validity
that is more difficult to control.
3. A nurse researcher is evaluating the quality of evidence using the GRADE (Grading of
Recommendations Assessment, Development and Evaluation) approach. The initial
highquality rating for randomized controlled trials can be downgraded for which of the
following reasons?
A) Large effect size and dose-response gradient
B) Risk of bias, inconsistency, indirectness, imprecision, and publication bias
C) Strong confounding and effect modification
D) High external validity and generalizability
- detailed answer 100 % correct :-B
Rationale: Under the GRADE approach, RCTs are initially rated as high-quality evidence but
can be downgraded based on five domains: risk of bias, inconsistency (heterogeneity),
indirectness (applicability), imprecision (wide confidence intervals), and publication bias.
Conversely, evidence can be upgraded based on large effect size, dose-response gradient, and
plausible confounding.
4. A nurse is conducting a meta-analysis and is deciding between using a fixed-effects
model versus a random-effects model. Which of the following best describes the key
difference in the assumptions underlying these two models?
A) Fixed-effects models assume the true effect size is identical across all studies, while
random-effects models assume the true effect size varies
B) Fixed-effects models produce wider confidence intervals than random-effects
modelsC) Random-effects models give more weight to smaller studies compared to fixed-
effects models
, D) Fixed-effects models can only be used when heterogeneity is greater than 50%
- detailed answer 100 % correct :-A
Rationale: The fundamental difference is the assumption about the underlying true effect size.
Fixed-effects models assume a single, common true effect across all studies (any variation is
due to sampling error). Random-effects models assume that the true effect size varies across
studies due to differences in study populations, interventions, or other factors.
5. A nurse researcher is performing a network meta-analysis comparing multiple
interventions for pain management. Which of the following represents a critical
assumption of network meta-analysis that must be satisfied for valid inference?
A) All studies included in the network must have the same sample size
B) The consistency assumption, meaning that direct and indirect evidence are in agreement
C) All interventions must be compared against placebo
D) Studies must be published within the last five years
- detailed answer 100 % correct :-B
Rationale: The consistency (or transitivity) assumption in network meta-analysis requires that
direct and indirect evidence are consistent with each other. If direct comparisons between two
interventions conflict with indirect comparisons through a third intervention, the results of the
network meta-analysis may be invalid.
6. A nurse is appraising a study that used a regression discontinuity design to evaluate
the impact of a new nurse staffing policy on patient outcomes. In this design, the key
feature that supports causal inference is:
A) Random assignment of hospitals to the intervention
B) Comparison of outcomes for units just above and below the staffing ratio threshold
C) Matching hospitals on key characteristics
D) Using instrumental variables to control for confounding
- detailed answer 100 % correct :-B
