Literature Screening and Data Extraction Services

In evidence-based research, literature screening and data extraction form the bedrock of high-quality outputs such as systematic reviews, meta-analyses, health technology assessments (HTAs), and clinical practice guidelines. These critical processes are more than just administrative steps—they determine the scientific validity, reproducibility, and credibility of your entire study.

At CliEvi, we specialize in offering accurate, transparent, and methodologically sound literature screening and data extraction services for clinical, biomedical, public health, and real-world evidence studies. Whether you are conducting a PRISMA-compliant systematic review, a rapid review for a policymaker, or a regulatory submission requiring transparent evidence, our expert team ensures every eligible study is screened meticulously and all relevant data is extracted systematically using globally accepted frameworks.

Why Literature Screening and Data Extraction Matter

Precision in Screening = Quality of Evidence

Poorly conducted screening can lead to irrelevant inclusions or critical exclusions, both of which may skew your findings. Missed studies might introduce bias, while wrongly included studies may dilute or distort your conclusions.

Structured Data Extraction = Analytical Rigor

Data extraction is not merely copying numbers—it involves interpreting, translating, and structuring data into consistent formats. This step is pivotal in determining what goes into your meta-analysis, risk of bias tables, GRADE assessments, and summary of findings tables.

Our Comprehensive Services

CliEvi provides end-to-end literature screening and data extraction support, from the formulation of criteria to final outputs ready for publication or regulatory review.

1. Screening Based on Inclusion and Exclusion Criteria

We screen titles, abstracts, and full texts based on pre-defined eligibility criteria. These may include:

• Population, Intervention, Comparator, Outcome (PICO)
• Study design (RCTs, observational studies, case series)
• Setting and geography
• Language and publication year
• Sample size thresholds or quality filters

Our approach ensures every article goes through two independent reviewers followed by consensus resolution and documentation of reasons for exclusion.

2. PRISMA-Compliant Flow Diagrams

We generate a transparent and reproducible PRISMA flow diagram, detailing the number of records:

• Identified through databases and registries
• Screened at abstract and full-text levels
• Excluded with reasons
• Finally included in synthesis

This is essential for peer-reviewed publication and ensures compliance with PRISMA 2020 or PRISMA-S (search extension) guidelines.

3. Data Extraction Form Creation and Standardization

We design custom data extraction forms suited to your study design and research question. Formats can be developed in:

• Microsoft Excel/Google Sheets
• Covidence
• Rayyan
• EPPI-Reviewer
• RevMan
• DistillerSR

Fields may include bibliographic data, study design, sample size, population details, intervention characteristics, outcome measures, results, risk of bias, funding source, conflict of interest, etc.

4. Extraction of Study and Outcome-Level Data

We extract both qualitative and quantitative data from selected studies. This includes:

• Study setting, population, duration, and follow-up
• Intervention and comparator details
• Primary and secondary outcome values
• Effect measures (mean difference, odds ratios, hazard ratios)
• Confidence intervals and p-values
• Time-to-event data
• Risk of bias components (using tools like Cochrane RoB 2.0, ROBINS-I, or QUADAS-2)

We flag missing data or inconsistencies and annotate such cases for future sensitivity analysis.

5. Summary Tables and Evidence Matrix

Our team prepares high-quality evidence synthesis tables including:

• Characteristics of included studies
• Risk of bias assessment
• Summary of findings
• Evidence mapping
• GRADE table construction (if applicable)

All tables are publication-ready, customizable to journal guidelines or HTA submission templates.

6. Double Extraction and Validation

To minimize errors, we offer double-data extraction, where two independent reviewers extract the same data and discrepancies are resolved through discussion or arbitration. This enhances reliability, especially for high-stakes reviews.

7. Integration with Analysis Teams

We collaborate directly with your biostatisticians or meta-analysis team to ensure the extracted data is formatted correctly for:

• Meta-analysis software (RevMan, Stata, R meta-packages)
• Forest plot and funnel plot generation
• Subgroup and sensitivity analyses
• Meta-regression

Use Cases and Applications

Our literature screening and data extraction services cater to a wide range of applications:

Systematic Reviews and Meta-Analyses

Our core clientele includes academic researchers, PhD scholars, and clinicians conducting Cochrane-style or journal-targeted reviews across medical disciplines.

Preclinical and Laboratory Evidence Reviews

We extract data from in vitro or animal model studies, often for regulatory dossiers or translational research papers.

Health Technology Assessments (HTA)

We provide evidence matrices and critical appraisals as per HTA frameworks such as NICE (UK), IQWiG (Germany), AHRQ (US), and NECA (Korea).

Real-World Evidence Syntheses

We support RWE-focused literature extraction, especially from EMR studies, registries, observational designs, or digital health implementations.

Clinical Guidelines Development

We provide data summaries and extracted evidence for organizations developing clinical practice guidelines, such as specialty societies or hospital committees.

Tools and Software We Use

Our team is proficient in the leading platforms and software tools:

• Rayyan for blinded title/abstract screening
• Covidence for structured review workflows
• DistillerSR for enterprise-grade screening and extraction
• RevMan for Cochrane-compliant reviews
• EPPI-Reviewer for mixed-methods syntheses
• Excel + R for custom extraction and tabulation

We also use reference management tools like EndNote, Zotero, and Mendeley for deduplication and reference tracking.

Key Strengths of CliEvi’s Services

✔ Dual Independent Reviewers

Every screening and extraction task is handled by at least two trained reviewers to enhance validity.

✔ Medical and Statistical Expertise

We understand what matters in evidence—what constitutes robust endpoints, relevant effect sizes, and bias concerns.

✔ Transparent Documentation

All exclusion decisions, extraction notes, and assumptions are documented in an auditable format.

✔ Flexible Formats

We adjust our output to your needs—academic paper, regulatory submission, grant application, or technical report.

✔ Timeliness and Scalability

We handle both rapid reviews and comprehensive systematic reviews with scalable team size and fast turnarounds.

Example Scenario

Example: Literature Review on Mobile Health (mHealth) for Type 2 Diabetes Management

• Scope: RCTs and observational studies from the Middle East (2013–2023)
• Databases: PubMed, Scopus, Embase, Web of Science
• Screening Output:
• Total records: 2,140
• After deduplication: 1,876
• Abstracts screened: 1,876
• Full texts reviewed: 232
• Included in final analysis: 38
• Data Fields Extracted: Study ID, Country, Sample Size, mHealth modality, HbA1c outcome, Compliance, Risk of Bias

The extracted dataset was used for both narrative synthesis and pooled meta-analysis.

Who Can Benefit

• Medical Researchers and Authors preparing systematic or scoping reviews
• CROs and Pharma compiling dossiers for submission to regulators
• HTA Bodies needing structured data for technology appraisals
• Clinical Practice Committees synthesizing evidence for guidelines
• Academic Supervisors and PhD Students needing support for thesis work
• Public Health Organizations evaluating implementation interventions

Our Process

1. Kickoff Call: Define scope, criteria, and deliverables
2. Search Completion: Upload references and deduplicate
3. Title and Abstract Screening: Dual reviewers + conflict resolution
4. Full-Text Screening: Eligibility check and PRISMA flow creation
5. Data Extraction: Form development, data capture, QC process
6. Final Delivery: Export of datasets, tables, and documentation

Getting Started

Whether you’re beginning a Cochrane-style review, need support for a grant or thesis, or require a real-world evidence synthesis, CliEvi’s Literature Screening and Data Extraction Services are tailored to meet your research goals efficiently and rigorously.

We offer custom quotes, free initial consultations, and flexible delivery models—per-review, per-hour, or subscription-based.