Evidence map›Paper›PMID 17060757›Full record

SynthesisAnnals of surgery2006

Comparison of effects in randomized controlled trials with observational studies in digestive surgery.

Satoru Shikata, Takeo Nakayama, Yoshinori Noguchi, Yoshinori Taji, Hisakazu Yamagishi

Abstract readMeta-Analysis
PubMed Full text at PMC Publisher
In one paragraph

Synthesis in Annals of surgery, 2006. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 31 papers, 11 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
31citing papers in PubMed, 11 pooled it
–field-weighted citation impact
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

31 citing papers in PubMed, 11 syntheses or guidelines pooled it.

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  10. Meta-analytic comparison of randomized and nonrandomized studies of breast cancer surgery.Canadian journal of surgery. Journal canadien de chirurgie · 2012
    Pooled it
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  12. Impact of neoadjuvant chemotherapy on short-term outcomes after simple and complex minimally invasive minor hepatectomy for colorectal liver metastases: A propensity-score matched and coarsened exact matched study.European journal of surgical oncology : the journal of the European Society of Surgical Oncology and the British Association of Surgical Oncology · 2024
    Article
  13. Review
  14. Impact of neoadjuvant chemotherapy on the difficulty and outcomes of laparoscopic and robotic major liver resections for colorectal liver metastases: A propensity-score and coarsened exact-matched controlled study.European journal of surgical oncology : the journal of the European Society of Surgical Oncology and the British Association of Surgical Oncology · 2023
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4 · The record

Corrections and comments

5 · Who and what money

Authors and funding

5 authors.

Satoru ShikataDepartment of Digestive Surgery, Kyoto Prefectural University of Medicine, Kyoto, Japan.
Takeo Nakayama
Yoshinori Noguchi
Yoshinori Taji
Hisakazu Yamagishi

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

objectivesTo compare the results of randomized controlled trials versus observational studies in meta-analyses of digestive surgical topics. SUMMARY BACKGROUND DATA: While randomized controlled trials have been recognized as providing the highest standard of evidence, claims have been made that observational studies may overestimate treatment benefits. This debate has recently been renewed, particularly with regard to pharmacotherapies.

methodsThe PubMed (1966 to April 2004), EMBASE (1986 to April 2004) and Cochrane databases (Issue 2, 2004) were searched to identify meta-analyses of randomized controlled trials in digestive surgery. Fifty-two outcomes of 18 topics were identified from 276 original articles (96 randomized trials, 180 observational studies) and included in meta-analyses. All available binary data and study characteristics were extracted and combined separately for randomized and observational studies. In each selected digestive surgical topic, summary odds ratios or relative risks from randomized controlled trials were compared with observational studies using an equivalent calculation method.

resultsSignificant between-study heterogeneity was seen more often among observational studies (5 of 12 topics) than among randomized trials (1 of 9 topics). In 4 of the 16 primary outcomes compared (10 of 52 total outcomes), summary estimates of treatment effects showed significant discrepancies between the two designs.

conclusionsOne fourth of observational studies gave different results than randomized trials, and between-study heterogeneity was more common in observational studies in the field of digestive surgery.

Indexed as

Digestive System Surgical ProceduresHumansObservationRandomized Controlled Trials as TopicRetrospective Studies

Identifiers

PMID17060757
PMCPMC1856609

What OpenQuestion holds

Textmetadata
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 OpenQuestion graph.