Evidence map›Paper›PMID 31129605›Full record

SynthesisBMJ open2019

Creation of a database to assess effects of omega-3, omega-6 and total polyunsaturated fats on health: methodology for a set of systematic reviews.

Lee Hooper, Asmaa Abdelhamid, Julii Brainard, Katherine H O Deane, Fujian Song, PUFAH group

Open access · goldAbstract readSystematic Review
PubMed Full text at PMC Publisher
In one paragraph

Synthesis in BMJ open, 2019. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 9 papers, 7 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
9citing papers in PubMed, 7 pooled it
1.4field-weighted citation impact, top 21% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

9 citing papers in PubMed, 7 syntheses or guidelines pooled it, 14 citations in OpenAlex.

  1. Pooled it
  2. Pooled it
  3. Reduction in saturated fat intake for cardiovascular disease.The Cochrane database of systematic reviews · 2020
    Pooled it
  4. Reduction in saturated fat intake for cardiovascular disease.The Cochrane database of systematic reviews · 2020
    Pooled it
  5. Pooled it
  6. Pooled it
  7. Pooled it
  8. Review
  9. Observational
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

6 authors at 1 institution in 1 country.

Lee HooperNorwich Medical School, University of East Anglia, Norwich, UK.ORCID 0000-0002-7904-3331
Asmaa AbdelhamidNorwich Medical School, University of East Anglia, Norwich, UK.
Julii BrainardNorwich Medical School, University of East Anglia, Norwich, UK.ORCID 0000-0002-5272-7995
Katherine H O DeaneSchool of Health Sciences, University of East Anglia, Norwich, UK.ORCID 0000-0002-0805-2708
Fujian SongNorwich Medical School, University of East Anglia, Norwich, UK.
PUFAH group
University of East Anglia · GB

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

objectiveTo create a database of long-term randomised controlled trials (RCTs) comparing higher with lower omega-3, omega-6 or total polyunsaturated fatty acid (PUFA), regardless of reported outcomes, and to develop methods to assess effects of increasing omega-6, alpha-linolenic acid (ALA), long-chain omega-3 (LCn3) and total PUFA on health outcomes.

designSystematic review search, methodology and meta-analyses. DATA SOURCES: Medline, Embase, CENTRAL, WHO International Clinical Trials Registry Platform, Clinicaltrials.gov and trials in relevant systematic reviews. ELIGIBILITY CRITERIA: RCTs of ≥24 weeks' duration assessing effects of increasing ALA, LCn3, omega-6 or total PUFAs, regardless of outcomes reported. DATA SYNTHESIS: Methods included random-effects meta-analyses and sensitivity analyses. Funnel plots were examined, and subgrouping assessed effects of intervention type, replacement, baseline diabetes risk and use of diabetic medications, trial duration and dose. Quality of evidence was assessed using Grading of Recommendations Assessment, Development and Evaluation (GRADE).

resultsElectronic searches generated 37 810 hits, de-duplicated to 19 772 titles and abstracts. We assessed 2155 full-text papers, conference abstracts and trials registry entries independently in duplicate. Included studies were grouped into 363 RCTs comparing higher with lower omega-3, omega-6 and/or total PUFA intake of at least 6 months' duration-the Database.Of these 363 included RCTs, 216 RCTs were included in at least one of our reviews of health outcomes, data extracted and risk of bias assessed in duplicate. Ninety five RCTs were included in the Database but not included in our current reviews. Of these 311 completed trials, 27 altered ALA intake, 221 altered LCn3 intake and 16 trials altered omega-3 intake without specifying whether ALA or LCn3. Forty one trials altered omega-6 and 59 total PUFA.The remaining 52 trials are ongoing though 13 (25%) appear to be outstanding, or constitute missing data.

conclusionsThis extensive database of trials is available to allow assessment of further health outcomes.

Indexed as

Health BehaviorChronic DiseaseDatabases, FactualFatty Acids, Omega-3Fatty Acids, Omega-6Fatty Acids, UnsaturatedHumansRandomized Controlled Trials as TopicFatty Acids, Omega-3Fatty Acids, Omega-6Fatty Acids, Unsaturateddatabase of trialsfatty acids, omega-3fatty acids, omega-6fatty acids, unsaturatedmeta-analysis as topicsystematic review methodology

Identifiers

PMID31129605
PMCPMC6537970
OpenAlexW2944935997

What Socratic holds

Textmetadata
LicenceCC BY-NC
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the Socratic graph.