Citation counts vary: course reviews often use 25–75 sources; journal reviews cite 50–200+, with exact limits set by each journal.
Writers in medicine and public health often ask how many references they should include. There is no one magic number for every project. The right count depends on the review type, the venue, the scope, and how mature the topic is. This guide gives clear ranges you can use right away, with sources and practical steps to choose a number that fits your assignment or target journal.
How Many References Should A Health Sciences Review Include?
For most coursework in nursing, pharmacy, epidemiology, or allied health, a focused narrative review that spans a single clinical question tends to land between 25 and 75 citations. Capstone projects and theses often stretch past 100. In journals, broad narrative reviews commonly run from 80 to 200 references. Evidence syntheses such as systematic reviews and scoping reviews often exceed 150 total citations because they cite search methods, protocols, screening tools, appraisal tools, and each included study.
Quick Ranges By Context
Use the table below as a first pass, then adjust with the steps that follow.
| Review Context | Typical Citation Range | What Drives The Range |
|---|---|---|
| Undergrad/Grad Course Paper | 25–75 | Scope is narrow; instructor rubrics set expectations. |
| Honours Thesis/Master’s Thesis | 60–150 | Broader scope; methods and historical papers often included. |
| Journal Narrative Review | 80–200 | Wide scan of subtopics; background and consensus statements included. |
| Scoping Review | 100–250+ | Maps a field; often cites many descriptive records. |
| Systematic Review (no meta-analysis) | 100–200+ | Search strategy, appraisal tools, each included study, and context papers. |
| Systematic Review With Meta-analysis | 150–300+ | All the above plus statistics and sensitivity checks. |
Why “It Depends” Still Gives A Usable Number
Editors and graders look for sufficiency, not excess. Your aim is to cite enough high-quality studies to support the claim that you searched well and covered the topic. Too few sources can miss key trials or guidance; too many can drown readers and bloat your word count. The sweet spot is the smallest set that covers the field without gaps.
Anchor Your Range To Real Policies
Many journals publish article-type limits that include a reference band. One leading general-medicine title lists “50–75 references” for systematic reviews without meta-analysis. That policy helps set expectations for reviews pitched to clinical audiences. Method standards matter too. The PRISMA 2020 checklist lays out what a transparent evidence synthesis should report; when you follow it, citation counts rise because you reference search methods and all included studies.
Evidence On Typical Included Studies
Audits of Cochrane reviews found a median of only a few included studies in older sets and wide variation across topics; more recent longitudinal work shows medians creeping upward as fields accumulate trials. That growth means a review on a mature therapy often needs far more citations than a review on a new device.
Pick Your Target Count In Five Steps
1) Match The Assignment Or Journal
Start with what the rubric or “Instructions for Authors” page asks. If your course brief says “about 30 sources,” your target is set. If your target journal lists a reference band for your article type, treat that as the ceiling unless a specific editor tells you otherwise. When a journal gives a band, pick a number near the middle unless the topic obviously needs more breadth.
2) Size The Field
Run a scoping search in one or two databases and look at hits by decade. A mature therapy or guideline area will return many trials and statements, which drives counts up. Newer topics may need fewer citations because fewer high-quality studies exist. In both cases, include the best methods papers and any core guidance used in your field.
3) Balance Depth And Relevance
Favor original studies and up-to-date guidance over duplicative secondary sources. When many studies repeat the same finding, cite landmark trials and the most rigorous pooled analyses, not every small case series. If older trials set context for current care, include them without letting them crowd out newer trials.
4) Trim Redundancy
Scan your list for pairs that say the same thing. Keep the stronger or more current one. Cut sources that sit outside your question. Replace generic background citations with a single high-quality review where possible.
5) Check Style And Transparency
Health journals rely on numbered reference styles such as AMA or Vancouver. Make sure in-text numbering matches the list and that every item is retrievable. If you use reporting checklists, cite them. If you post a protocol or register a review, cite that too.
What Different Review Types Usually Need
Narrative Reviews
These synthesize what is known across a topic for readers who need a clear picture. You will cite landmark trials, practice guidelines, and recent high-quality reviews. Because breadth is the goal, counts run higher than a course paper and often touch 100 or more once subtopics are included.
Scoping Reviews
These map concepts and study designs without rating effect size. Expect long reference lists because you catalog many records and include methods citations. Transparent search reporting boosts the total.
Systematic Reviews
Here you must cite the protocol or registry entry, the full search strategy sources, screening tools, bias tools, each included study, and key context papers. That stack alone can push you past 150 items in busy topics, while narrow questions with few trials may land near 100. Some clinical journals set a band for systematics, which helps you aim your draft.
When A Lower Or Higher Count Makes Sense
Good Reasons To Aim Lower
- The topic is narrow with only a few high-quality trials.
- You are writing a short assignment with a strict word cap.
- A journal’s article-type page sets a low reference band for brief formats.
Good Reasons To Aim Higher
- Your question spans multiple subtopics or settings.
- You must cite detailed search methods and every included study.
- You are summarizing safety, subgroup, and sensitivity checks that rely on extra sources.
How To Avoid Over-Or Under-Citing
Use A Screening Log
Keep a spreadsheet of everything you read with simple reasons for include/exclude. That reduces padding and protects against missed classics. If asked, you can show that your choices were systematic.
Prefer Primary Evidence For Claims
Use reviews to frame the topic, then cite the strongest trials or cohorts for the core claims. Secondary sources help with context, but primary studies carry the weight.
Watch Recency
Readers expect the newest high-quality evidence to appear in your list. When a landmark trial has a recent follow-up or update, cite the update. When practice changes after a major guideline, include it.
Common Reference Bands And What They Mean
The table below pulls public policies from respected sources so you can see concrete bands and standards. Treat these as examples; your target journal may differ.
| Source & Article Type | Reference Guidance |
|---|---|
| JAMA, Systematic Review (no meta-analysis) | Lists “50–75 references” for this article type; aligns with clinical readership needs. See the JAMA author guidance. |
| PRISMA 2020 Reporting Standard | Requires transparent reporting of search, selection, and included studies; meeting the checklist often raises counts; see PRISMA 2020. |
| Cochrane Handbook & Author Pages | No fixed cap; large reviews often contain many included studies and methods citations; see the Cochrane Handbook. |
Examples Of How Counts Shift With Topic Maturity
New Or Emerging Area
Few trials exist. You may rely on small pilot studies and early cohorts. A tight review can feel complete with 30–60 items, as long as methods and context are covered.
Busy Clinical Space
Think antihypertensives, diabetes care, or vaccine effectiveness. There are dozens of trials, updates, and practice guidelines. Reviews in these spaces often pass 150 items even after trimming overlap.
Cross-Disciplinary Question
Questions that mix biostatistics, implementation, and clinical outcomes pull in more sources. You may cite measurement papers, code repositories, appraisal tools, and trial reports. Counts climb, but each source earns its keep.
Practical Tips To Hit Your Target Range
Plan Your Outline Around Claims
Draft the main claims as bullets. Add the minimum set of sources that support each claim. This keeps the final list clear and lean.
Group Citations
When several studies back the same point, group them at one spot in the sentence. That keeps the text readable while showing breadth.
Use A Citation Manager
Reference tools save hours and cut format errors. They also help you de-duplicate and spot gaps.
End With A Brief Audit
- Do you cite the most recent high-quality trials and guidance?
- Does each subtopic have at least one primary study?
- Have you cut background padding that adds little?
Bottom Line On Choosing A Citation Count
Pick a band that matches your review type and venue, then use methods and editorial rules to fine-tune. For classroom work, a mid-range set of 25–75 sources covers most focused prompts. For journal reviews, expect 80–200 or more, with evidence syntheses rising further when topics are busy and reporting standards apply. When in doubt, check the target journal’s article-type page and align with its band.