Systematic Review Help UK: PICO, PRISMA and Critical Appraisal

A systematic review is not a long literature review with more references. It is a research method in its own right, with a question set in advance, a search that can be repeated by someone else, and explicit rules for deciding what counts as evidence. That discipline is exactly what makes systematic reviews so valuable — and so demanding. United Academic Help supports students through every stage of the process, from framing the question to writing up the findings, so that the finished review can stand up to a marker, supervisor or examiner who checks the method, not just the conclusions.

Students often underestimate how much planning a systematic review requires before a single database is searched. Without a clear question, agreed inclusion criteria and a recorded protocol, the search drifts, the screening becomes inconsistent, and the write-up ends up describing whatever studies were easiest to find. Our approach therefore starts before the search begins. We help you define a question that is narrow enough to be answerable and broad enough to matter, choose the right type of review for your assignment or dissertation, and document each decision so that your method section is accurate rather than reconstructed afterwards.

From question to protocol: PICO and registration

Most systematic reviews of interventions begin with PICO: Population, Intervention, Comparison and Outcome. Each element narrows the search in a useful way. A vague population such as “patients” becomes, for example, adults with type 2 diabetes in primary care. A vague intervention such as “exercise” becomes a defined programme with a duration and frequency. The comparison — usual care, no intervention, or an alternative treatment — determines which study designs are relevant, and the outcomes determine what data you will extract. For qualitative or non-intervention questions, related frameworks such as PEO or SPIDER may fit better, and choosing the right one at the start saves considerable rework later.

Once the question is set, the inclusion and exclusion criteria follow from it. These cover study design, population characteristics, language, date range and setting, and they must be decided before screening begins, not adjusted to include a favourite study. We help you write criteria that are defensible and workable: strict enough to keep the review focused, but not so narrow that almost nothing qualifies. The criteria, search strategy and analysis plan are then brought together in a protocol. Where your institution expects it, the protocol can be prepared for registration on a register such as PROSPERO, which protects you against accusations that the question or outcomes were changed after seeing the results.

A protocol is also a practical tool. It keeps two reviewers aligned when screening, it gives your supervisor something concrete to approve, and it becomes the backbone of your method chapter. Students who skip this stage often discover, halfway through screening, that they and their co-reviewer have been applying different rules. Re-screening hundreds of records at that point is painful and entirely avoidable. Time spent on the protocol is time saved twice over later.

Searching, screening and the PRISMA flow

A systematic search must be comprehensive, transparent and reproducible. That means searching more than one database, using both controlled vocabulary and free-text terms, and combining them with Boolean operators in a strategy that is recorded in full. We help you build searches for the databases your institution provides, adapt the strategy across databases without losing terms, and manage grey literature and hand-searching where your question requires it. Every search is dated and documented, so that your method section can state exactly where, when and how the evidence was sought.

Screening then proceeds in stages: titles and abstracts first, full texts second, with reasons recorded for exclusions at the full-text stage. This is where tools such as Rayyan or Covidence can help, but the software does not make the judgements — the criteria do. We support consistent, dual-style screening practice, help you resolve borderline cases against your protocol rather than by gut feeling, and produce a PRISMA flow diagram that accounts for every record: how many were identified, how many were duplicates, how many were excluded at each stage, and how many studies were finally included. A flow diagram with numbers that do not add up is an immediate red flag for a marker, so we check the arithmetic before the diagram is finalised.

The included studies are then described and extracted systematically. A data extraction table captures the study design, sample, intervention, outcomes and key findings for each paper, using the same fields throughout. That consistency is what allows the synthesis to be more than a series of mini-summaries. It also makes gaps visible: if half your studies do not report a key outcome, that is a finding in itself, and it should shape how confidently you can answer your question.

Critical appraisal: CASP, RoB 2 and synthesis

Including a study is not the same as trusting it. Critical appraisal asks whether a study’s design, conduct and reporting justify confidence in its results. For qualitative studies, the CASP checklists provide a structured set of prompts about aims, methodology, recruitment, data collection, reflexivity, ethics and analysis. For randomised trials, the Cochrane Risk of Bias 2 tool assesses bias arising from randomisation, deviations from the intended intervention, missing data, measurement and selective reporting. Other designs need other tools — for example, ROBINS-I for non-randomised studies of interventions, or the Newcastle-Ottawa Scale for cohort and case-control studies — and part of our support is helping you select the tool that matches each included design, rather than forcing every study through a single checklist.

Appraisal results must feed into the synthesis, not sit in an appendix that nobody revisits. A study at high risk of bias should not carry the same weight as a well-conducted trial, and a qualitative study with thin analysis should not anchor a theme on its own. We help you present appraisal findings clearly, usually in summary tables, and then show how they qualify your conclusions: where the evidence is strong, where it is promising but limited, and where it is too weak to support a recommendation. That honesty is what distinguishes a systematic review from an advocacy piece, and markers reward it.

Synthesis itself takes different forms depending on your question and data. Where studies are similar enough, a narrative synthesis draws out patterns, contradictions and explanations across them. Where quantitative results can be combined, meta-analysis may be appropriate, and we can support effect-size extraction, heterogeneity checks and the cautious interpretation of pooled results — including when not to pool, because combining unlike studies produces a precise-looking but meaningless average. Qualitative evidence may be synthesised thematically, building descriptive and then analytical themes across studies. Whichever route fits, the synthesis must stay traceable to the extracted data, so that a reader can follow any claim back to the studies behind it.

How our systematic review support works

Support from United Academic Help begins with your brief, your question as it currently stands, and any protocol, search or draft you already have. If you are starting from scratch, we work through question framing and protocol first, and only move to searching once the protocol is agreed. If you are part-way through, we pick up at your current stage — rescuing a drifting search, re-screening against tightened criteria, appraising studies you have already included, or restructuring a draft whose method section does not match what was actually done. You review each stage before the next begins, so the review remains yours and remains accurate.

Because systematic reviews involve many moving parts, we keep a shared record of decisions: the final question, criteria, databases and search dates, screening outcomes and appraisal judgements. That record becomes your audit trail, and it makes writing the method chapter straightforward rather than an exercise in memory. If your supervisor asks why a study was excluded or why a tool was chosen, you will have a clear answer. Drafts are revised with your feedback, and referencing is completed in the style your department requires.

Pricing and what is included

Systematic review support from United Academic Help starts from £20 per 1,000 words. Deadline tiers run from £20 for standard turnaround through £26, £32, £40 and £48 per 1,000 words for increasingly urgent deadlines. Masters-level work carries a 25% supplement and PhD-level work a 50% supplement, reflecting the methodological rigour, appraisal depth and synthesis work that higher-level reviews require. You receive a clear quote based on word count, level and deadline before work begins.

Every commission includes protocol and question development where needed, search and screening support, appraisal guidance, synthesis and write-up, and a final consistency check across the PRISMA diagram, extraction tables, appraisal summaries and text. If your review requires a meta-analysis, a qualitative synthesis, or a particular reporting standard, mention it at the outset so it can be planned and priced as part of one coherent project.

Frequently Asked Questions

What is the difference between a systematic review and a literature review? A literature review typically surveys and discusses published work on a topic, often selectively. A systematic review follows a pre-specified protocol, searches comprehensively, screens against explicit criteria, appraises quality and synthesises findings transparently, so that another researcher could repeat the process and reach a comparable set of studies.

Do I need to register my protocol? Registration is expected for many health-related reviews, commonly on PROSPERO, and it strengthens any review by showing that the question and methods were fixed in advance. For taught assignments, your department may not require formal registration, but preparing a written protocol is still good practice and is something we can help you produce.

Which appraisal tool should I use? It depends on your included study designs. CASP checklists suit qualitative and several other designs, RoB 2 suits randomised trials, and ROBINS-I suits non-randomised intervention studies. Using one generic checklist for every design is a common error; we help you match the tool to each study type in your review.

Can you help if I have already started searching? Yes. We regularly join reviews at the screening, appraisal or writing stage. If the early stages need tightening — for example, criteria that were never written down — we will help you document and, where necessary, re-run them properly rather than papering over the gap.

How long does a systematic review take? It depends on the breadth of the question and the number of records retrieved. A focused taught-level review can be completed in weeks; a large doctoral review takes months. Tell us your deadline and current stage, and we will advise honestly on what can be achieved well in the time available.

If your systematic review needs to be methodical rather than merely long, get in touch with United Academic Help. Share your question, your deadline and where you currently stand, and we will help you build a review whose search, screening, appraisal and synthesis a marker can trust.