A nursing evidence table is a structured matrix that helps you compare studies consistently before writing the synthesis. Its purpose is not to display as much information as possible. It should capture the study details, findings and limitations that are necessary to answer the review question and judge the strength of the evidence.
Used well, the table reduces study-by-study description, makes contradictions easier to investigate and creates an audit trail back to the original papers.
What a useful evidence table needs
- Columns derived from the review question and assessment requirements.
- The same extraction rules applied to every included study.
- Clear separation between reported findings and your appraisal.
- Units, denominators and time points where relevant.
- Source locations so important entries can be verified.
- Design-sensitive appraisal rather than one generic quality score.
- Enough detail to support synthesis without making the table unreadable.
What an evidence table is
An evidence table records comparable information from selected studies in a consistent format. Depending on the project, fields can include citation, country, aim, design, setting, sample, intervention or exposure, outcome measures, findings, limitations and appraisal.
It differs from a reference list because it records what each study did and found. It also differs from an annotated bibliography because the same fields are applied across studies, making direct comparison possible.
Systematic reviews may use the terms data-extraction table or study-characteristics table. The exact format varies by methodology and university requirements.
Start with the review question
Do not begin with a generic spreadsheet template. Break the research question into the information that will matter during synthesis.
For a review of nurse-led education for adults with heart failure, for example, useful fields may include:
- patient population;
- setting;
- education format and provider;
- intervention duration or intensity;
- comparator;
- adherence measure;
- follow-up time;
- effect estimate; and
- important methodological limitations.
A qualitative review would need different fields, such as sampling logic, data-generation method, analytic approach, reflexivity and themes.
Choose columns that support a later decision
| Column | What to record | Why it matters |
|---|---|---|
| Citation/context | Author, year, country or health-system context | Identifies the study and supports transferability judgements |
| Aim | Study purpose in concise language | Shows relevance to the review question |
| Design/setting | Design, recruitment setting and study period | Defines what conclusions are possible |
| Sample | Size, characteristics, eligibility and attrition | Shows selection and representativeness issues |
| Intervention/exposure | Content, delivery, dose and comparator where relevant | Prevents unlike interventions being treated as identical |
| Outcome/phenomenon | Measure, instrument or experience studied | Clarifies what was actually assessed |
| Main finding | Relevant result, estimate or qualitative finding | Provides the evidence used in synthesis |
| Limitations/appraisal | Specific methodological concerns and their implications | Supports appropriate weighting |
| Source location | Page, table, figure or supplementary file | Makes verification efficient |
Add a column only when it will influence synthesis, appraisal or reporting. A wide table full of unused details creates work without improving the argument.
Create extraction rules before filling the table
Consistency requires decisions about how each field will be recorded. Define, for example:
- whether sample size means recruited, randomised or analysed participants;
- which follow-up time point takes priority;
- whether adjusted estimates are preferred;
- how missing information will be labelled;
- how multiple reports from the same study will be linked; and
- how qualitative themes will be represented without stripping away context.
If the paper does not report a detail, write not reported rather than inferring or inventing it.
Pilot the table with two contrasting studies before completing the full extraction. This often reveals vague headings and missing fields early.
Extract from the full paper, not the abstract alone
Abstracts often omit sample attrition, measurement details, subgroup analyses and limitations. Check the methods, results, tables, figures and supplementary material.
Record findings neutrally before interpreting them. For example, write that one group had a lower mean score at 12 weeks before deciding whether the difference is clinically important.
Preserve units and denominators. A relative reduction is not the same as a percentage-point reduction, and a qualitative finding should not be presented as though it estimates prevalence.
Separate extraction from appraisal
Extraction asks what the study reports. Appraisal asks how much confidence should be placed in that evidence.
The JBI critical appraisal tools provide design-specific questions for evaluating different types of studies (JBI, n.d.-a). Other approved tools may also be appropriate.
A score alone is usually not enough. Explain the consequence of the limitation. High attrition, for example, is important because participants lost to follow-up may differ systematically from those analysed. Lack of blinding may matter more for subjective outcomes than for an objective laboratory result.
Adapt the table to study design
Randomised or quasi-experimental studies
Record allocation, comparator, baseline similarity, attrition, intervention detail, outcome measure, time point, effect estimate and uncertainty. Note important departures from the planned intervention or analysis.
Observational quantitative studies
Record sampling, exposure, outcome, relevant confounders, missing data and adjusted results. The STROBE statement supports transparent reporting of observational research but is not itself a risk-of-bias tool (von Elm et al., 2007).
Qualitative studies
Capture the methodological approach, sampling logic, participant context, data-generation method, analysis, reflexivity and key themes. Do not compress complex findings into a yes/no result.
Systematic or scoping reviews
Record the review design, databases, eligibility criteria, appraisal method, included-study count, synthesis approach and main findings. If several reviews include overlapping primary studies, make that overlap visible.
PRISMA supports systematic-review reporting but should not be used as a quality score (Page et al., 2021).
Use the table to create synthesis
The completed table should make comparison easier. Sort or group studies by outcome, intervention component, population, setting or theme and ask:
- Where do findings converge?
- Where do they differ?
- Can differences be explained by design, population, intervention intensity, measurement or follow-up?
- Which findings deserve the greatest confidence?
- Which important outcomes remain poorly studied?
For example, three discharge-education studies may all report “improvement,” but one may measure knowledge immediately after teaching, another medication adherence at four weeks and another readmission at three months. The table helps prevent these different outcomes from being treated as equivalent evidence.
Weight evidence rather than count studies
Five weak cross-sectional studies do not automatically outweigh one rigorous trial for an effectiveness question. Conversely, a trial may provide little information about acceptability or patient experience, where qualitative research contributes a different kind of evidence.
Match the design to the claim. The purpose of the table is to make that judgement easier, not to produce a vote count.
Keep an audit trail
A source-location column can record page numbers, table numbers or supplementary files for important extracted items. This helps when checking results, responding to supervisor feedback or resolving discrepancies between drafts.
Version the extraction file when changing the template or decision rules. If a new field becomes important halfway through, add it consistently across all previously extracted studies.
Common evidence-table mistakes
- Copying information from abstracts without checking full texts.
- Using different levels of detail for different studies.
- Mixing the study’s findings with your own interpretation in the same cell.
- Ignoring denominators, units, missing data or time points.
- Using one quality score without explaining important limitations.
- Filling the table with information that never influences the synthesis.
- Changing columns halfway through without updating earlier rows.
- Using another review’s extraction table as though you extracted the studies yourself.
Presentation and accessibility
Follow the assessment brief when deciding whether the table belongs in the main text or an appendix. For wide tables, landscape orientation may help. Use readable type, clear headings and consistent abbreviations.
Do not shrink the table until it becomes unreadable. A detailed extraction table can sit in an appendix while a shorter summary table appears in the results or literature-review chapter where appropriate.
Academic integrity
The table should reflect your own engagement with the included evidence. Cite the studies, paraphrase accurately and do not invent missing information or alter results.
For transparent service standards, see About Nursing Dissertation Service. The student feedback and review policy explains how feedback may be handled; it is not a page of verified testimonials.
Final evidence-table checklist
- Every column serves the review question or marking criteria.
- The same extraction definitions were applied to each study.
- Important entries can be traced to the source.
- Design, sample, setting, measures and time points are clear.
- Numerical findings include relevant units and denominators.
- Study findings are separated from appraisal.
- Appraisal explains the consequence of important limitations.
- The table supports comparison rather than study-by-study description.
- Abbreviations are defined and presentation remains readable.
- The final set of studies matches the eligibility criteria and reference list.
Frequently asked questions
How many studies should the table include?
Include the studies required by the stated review method and eligibility criteria. There is no universal target number.
Should the evidence table be in the appendix?
Follow the brief. A detailed extraction matrix often fits better in an appendix, while a compact study-characteristics table may sit in the main chapter.
Can Excel be used?
Yes. Excel or another spreadsheet is useful for wide extraction, sorting and filtering. The consistency of the method matters more than the software.
Should p-values be included?
Include the statistics needed to interpret the result. For quantitative evidence, estimates and confidence intervals are often more informative than p-values alone.
Is the evidence table itself critical appraisal?
No. It can record appraisal findings, but critical appraisal requires reasoned judgement about bias, relevance and confidence.
Project-specific support
If an existing table is inconsistent or difficult to use for synthesis, the nursing systematic review support and contact page provide the relevant routes.
Related Nursing Guides
- How to Conduct a Critical Appraisal in Nursing Research: CASP, JBI and Other Tools
- How to Conduct Thematic Analysis in a Systematic Review: Nursing Guide
- How to Develop a Systematic Review Search Strategy for Nursing Research
Conclusion
A useful nursing evidence table creates a reliable bridge between reading and synthesis. Build it from the review question, apply consistent extraction rules, separate reported findings from appraisal and preserve enough source detail to verify important entries. The final table should make patterns, differences and limitations easier to explain in the written argument.
References
- JBI. (n.d.-a). Critical appraisal tools. https://jbi.global/critical-appraisal-tools
- JBI. (n.d.-b). JBI manual for evidence synthesis. https://synthesismanual.jbi.global/
- Page, M. J., McKenzie, J. E., Bossuyt, P. M., et al. (2021). The PRISMA 2020 statement: An updated guideline for reporting systematic reviews. BMJ, 372, n71. https://doi.org/10.1136/bmj.n71
- von Elm, E., Altman, D. G., Egger, M., Pocock, S. J., Gøtzsche, P. C., & Vandenbroucke, J. P. (2007). The STROBE statement: Guidelines for reporting observational studies. PLoS Medicine, 4(10), e296. https://doi.org/10.1371/journal.pmed.0040296