Most systematic reviews need 6–18 months; manuscripts often run 3,500–7,000 words, shaped by scope, journal limits, and team capacity.
A fair question pops up early for any review team: how long is a systematic review in both time and pages? The answer lives on two tracks. First, the project timeline from idea to publication. Second, the length of the article that journals will accept. Both vary with topic breadth, search yield, and whether a meta-analysis sits inside the plan. This guide gives clear ranges, a stage-by-stage clock, and page-planning cues you can use before the first database query.
How Long Does A Systematic Review Take: Realistic Timeline
Across healthcare and social science, common timelines land between 6 and 18 months for a full review. Large programs can stretch beyond two years when the question is broad or evidence is scattered. Peer-review and production add extra months that sit outside the team’s direct control. The ranges below assume two independent screeners, librarian input, and a standard risk-of-bias framework.
Stage-By-Stage Time Ranges
The table gives planning numbers that teams can tune to topic and staffing. Use the low end for a narrow, well-mapped field and the high end for a wide, multi-database sweep with grey literature.
| Stage | Typical Time | What Drives Length |
|---|---|---|
| Scope & Protocol (incl. registration) | 2–6 weeks | Clarity of PICO, protocol edits, approvals |
| Search Strategy Build & Pilots | 2–6 weeks | Number of databases, terminology spread |
| Comprehensive Searches | 1–4 months | Grey literature, trial registries, hand-searching |
| Title/Abstract Screening | 2–8 weeks | Hit count, two-reviewer process, tools |
| Full-Text Screening | 2–8 weeks | Access to PDFs, tie-break sessions |
| Data Extraction & Risk Of Bias | 1–3 months | Outcomes per study, study designs, piloting forms |
| Synthesis & Meta-Analysis | 2–8 weeks | Heterogeneity checks, subgroup plans, GRADE |
| Drafting, Edits & Approvals | 4–8 weeks | Author availability, figure builds, tables |
| Submission, Peer Review & Production | 1–6+ months | Journal queue, revisions, proofs |
Why Timelines Stretch Or Shrink
Topic width sets the pace. A narrow PICO that targets one setting and one outcome moves faster than a broad scope across ages, settings, and multiple outcomes. Yield matters too. Ten thousand search hits need more screening hours than one thousand. Team size and cadence play a part: two steady hours daily beat one long binge each week. Software and workflows help as well; citation managers, de-dupers, and screening apps cut idle time. A meta-analysis adds more clock time than a narrative synthesis. Finally, peer review can be quick or slow, and that part is outside the author group.
Evidence On Duration From Major Sources
Large methods groups track the real-world clock on reviews. Guidance from major handbooks notes that total time often runs past one year for a complete cycle, and some reviews need more than two years from protocol to publication when the scope is wide. A public health guide likewise cites a common 18-month arc for end-to-end work. Library guides also point out that the search phase alone can stretch to several months on complex topics.
Use The Core Standards
Two anchors keep both time and length under control. The first is the Cochrane Handbook, which lays out methods from scoping through synthesis; it also flags how full reviews can outlast short decision windows. The second is the PRISMA 2020 checklist, which lists the reporting items that shape your sections, figures, and flow diagram. Linking your plan to these two saves rework later and helps when journals weigh clarity and completeness.
See the Cochrane Handbook chapter and the PRISMA 2020 checklist.
How Long Is The Article Itself: Words And Pages
Most systematic review articles land near 3,500–7,000 words for the main text, not counting references or appendices. Some general-medicine titles cap main text around 3,000–4,000 words, while specialty and open-access outlets allow more room or move long tables to supplements. Length also tracks with study count and outcome breadth. A brief review with ten included trials needs fewer pages than one with sixty, three outcomes, and subgroup plans. When in doubt, write to the journal’s limits and push heavy detail to online files.
Word Budget By Section
Plan a tight abstract, a short background that sets the question, a detailed methods section, direct results, and a lean plain-language take-away. The table below shows a planning split. It is a guide, not a rule. Journal templates always win.
| Section | Typical Word Range | Notes |
|---|---|---|
| Abstract | 250–350 | Use a structured format tied to PRISMA |
| Background | 400–700 | Set the question; keep history short |
| Methods | 1,000–1,800 | Databases, criteria, bias tools, stats |
| Results | 800–1,600 | Study count, key effects, figures and tables |
| Discussion & Limits | 700–1,400 | Meaning, limits, next steps, update plan |
| Plain-Language Summary | 150–300 | Use clear words; avoid jargon |
Planning Tips That Save Weeks
Lock The Question Early
Write a crisp PICO with exact comparators and outcomes. Loose wording at the start creates search sprawl and long tie-break calls later. A tight scope also keeps the word count within a journal’s ceiling.
Build Searches With A Librarian
A trained searcher pays off in fewer misses and cleaner de-duping. Agree on databases, date limits, and language up front. Pilot one database, check a known-set of seed papers, then roll out the full run. That sequence trims back reruns and delays.
Pick Tools Before Screening Starts
Decide on a citation manager, screening app, and a data-extraction form before the first PDF lands. Pilot the form on three studies and adjust once. Shared templates cut drift and prevent rescoring later.
Schedule Short, Regular Blocks
Daily one-hour sessions beat a weekly marathon. Screening and extraction flow better in small, repeatable blocks. That rhythm also lowers error rates and speeds consensus calls.
Write As You Go
Capture methods live: exact strings, dates of each search, tools, and versions. Fill study-characteristics tables while extracting. When synthesis starts, much of the write-up already sits in place, and the final edit shifts from drafting to trimming.
When Fast Evidence Is Needed
Some teams deliver rapid reviews with trimmed steps. Typical trims include a narrower scope, a smaller set of databases, and single-reviewer screening with verification. That trade gives speed but reduces depth. State each change in the methods, and mark limits clearly so readers can weigh the findings.
Update Cycles And Maintenance
Evidence moves. Plan an update path when the field is growing. Signal-based triggers help: new major trials, new licensed products, or a change in practice patterns. A slim update can add searches, new studies, and a revised meta-analysis without rewriting the whole paper. When changes shift the bottom line, submit a full update.
Frequently Seen Bottlenecks
Access To Full Texts
Slow document delivery drags the schedule. Set up interlibrary loan early. Keep a shared folder with clear names so the same PDF is not requested twice.
Too Many Outcomes
A long list expands extraction forms and tables. Pick outcomes that match the decision the review is meant to support. Move any extras to a sensitivity or appendix plan.
Unplanned Subgroups
Adding subgroups late burns time and can muddle messages. If subgroups are likely, pre-specify them and keep the list tight.
A Quick Answer You Can Use
Time: plan 6–18 months, longer for big scopes and complex meta-analysis. Article length: plan 3,500–7,000 words for the main text, with long tables and extra figures placed in online files. Use the core handbooks and check a target journal’s limits before drafting. That mix keeps time under control and pages within range.