Systematic Reviews & Meta-analysis – N7000 Lecture

These flashcards cover definitions, processes, appraisal criteria, and key statistical concepts related to systematic reviews and meta-analyses presented in the N7000 lecture.

What is the fundamental difference between a narrative review and all other review types discussed?

Narrative reviews do not conduct all bias-reducing steps (a priori protocol, transparent search, risk-of-bias assessment, systematic extraction, synthesis).

Which review type maps key concepts, features, and volume of evidence and can be a precursor to a systematic review?

A Scoping Review.

Name the six main types of literature reviews covered in the lecture.

Systematic review (with/without meta-analysis), Integrative review, Scoping review, Umbrella review, Meta-synthesis, Narrative review.

Which two review types always include a critical appraisal of study quality?

Systematic reviews and Umbrella reviews.

In the evidence hierarchy, where do systematic reviews and meta-analyses sit?

At the highest level (Level 1 evidence).

What guiding element should always precede (be written before) a systematic, integrative, scoping, or umbrella review?

An a priori protocol.

Which review type can include both quantitative and qualitative studies without being limited to one design?

An Integrative Review.

What is the primary purpose of a systematic review?

To answer a defined clinical question via an exhaustive, reproducible synthesis and appraisal of the literature.

How does a meta-analysis extend a systematic review?

It statistically pools results to provide a quantitative estimate of effect across studies.

List the five core steps in the systematic review process.

Define clinical question, search the literature, appraise & extract data, synthesize/combine results, place findings in context.

Which table characteristic distinguishes narrative reviews from systematic or integrative reviews in terms of bias control?

Narrative reviews lack transparent search strategies and risk-of-bias assessments.

Why must multiple reviewers independently screen and extract data in systematic reviews?

To minimize bias and ensure adherence to the protocol.

What three questions underpin critical appraisal of any research study?

Are the results valid? What are the results? Can I apply them to patient care?

Name two tools/guidelines commonly used to report or conduct scoping reviews.

PRISMA-ScR (Tricco et al.) and Peters et al. guidance for scoping reviews.

What statistical concept measures the precision of an individual study’s effect estimate in a forest plot?

The Confidence Interval (CI).

Define publication bias.

The tendency for studies with positive/significant results to be published more often than those with negative or non-significant results.

Which graphical method helps detect publication bias in meta-analyses?

A Funnel Plot.

What does study heterogeneity refer to in meta-analysis?

Variability across studies in participants, interventions, outcomes, or methodologies that may affect the validity of pooling data.

Give two statistical tests/approaches used to assess heterogeneity.

Chi-square (Q) test and I² statistic.

According to the lecture, what odds ratio was found for text messaging improving medication adherence?

Pooled OR ≈ 2.11 (95 % CI 1.52–2.93).

After adjusting for publication bias, what was the revised odds ratio for the same meta-analysis?

OR ≈ 1.68 (95 % CI 1.18–2.39).

What are the three discrete steps of evidence appraisal highlighted?

Validity, importance (results), applicability.

Which review type deliberately summarizes evidence from existing systematic reviews on a broad topic?

An Umbrella Review.

What acronym describes the checklist used for detailed appraisal of SR/MA according to JBI?

No acronym; it is the 11-item JBI Critical Appraisal Checklist for Systematic Reviews & Research Syntheses.

State two JBI checklist items related to search quality.

Was the search strategy appropriate? Were the sources/resources used adequate?

Why is ‘grey literature’ searching important in a systematic review?

To reduce publication bias by including unpublished or non-indexed studies.

Which element of the Oxford 2011 Levels of Evidence may downgrade a study’s level?

Poor quality, imprecision, indirectness, inconsistency, or very small effect size.

What is the main advantage of a meta-analysis over individual studies regarding statistical power?

It increases power to detect small but significant effects by combining sample sizes.

In a forest plot, what does the diamond symbol usually represent?

The pooled (overall) effect estimate and its confidence interval.

What factor determines whether pooling data in meta-analysis is justifiable?

Acceptable level of clinical and methodological homogeneity among studies.

What is meant by ‘transparent search strategy’ in a review?

A fully documented, reproducible description of databases, keywords, filters, and dates searched.

Which review type focuses on synthesizing qualitative research findings?

Meta-synthesis.

What does ‘risk of bias assessment’ aim to evaluate in each study?

Potential systematic errors that could distort study results, such as selection, performance, detection, or reporting biases.

Name two common standardized tools for risk-of-bias assessment in randomized trials.

The Cochrane Risk of Bias tool and the JBI RCT Checklist.

What key question determines the applicability of SR/MA findings to practice?

Are study participants, settings, and interventions similar enough to my patients and resources?

Which publication provided the case example meta-analysis on mobile text messaging?

Thakkar et al., JAMA Internal Medicine, 2016.

What is an ‘a priori protocol,’ and why is it critical?

A pre-specified plan describing objectives, methods, and analyses that guards against data-driven bias.

Define an ‘umbrella review’ in one sentence.

A synthesis of evidence drawn exclusively from existing systematic reviews and meta-analyses on related questions.

What does the I² statistic quantify?

The percentage of total variation across studies due to heterogeneity rather than chance.