SynthesisBMJ (Clinical research ed.)2009
Written informed consent and selection bias in observational studies using medical records: systematic review.
Synthesis in BMJ (Clinical research ed.), 2009. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT03805230 (Postoperative Vasopressor Usage), which is not on this map. Cited by 124 papers, 5 of them syntheses that pooled 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.
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.
Postoperative Vasopressor Usage : a Prospective International Observational Study (SQUEEZE)
Who cites it
124 citing papers in PubMed, 5 syntheses or guidelines pooled it.
- Opportunities and Challenges of Cardiovascular Disease Risk Prediction for Primary Prevention Using Machine Learning and Electronic Health Records: A Systematic Review.Reviews in cardiovascular medicine · 2025Pooled it
- Opt-In and Opt-Out Consent Procedures for the Reuse of Routinely Recorded Health Data in Scientific Research and Their Consequences for Consent Rate and Consent Bias: Systematic Review.Journal of medical Internet research · 2023Pooled it
- FUTURE OF THE LANGUAGE MODELS IN HEALTHCARE: THE ROLE OF CHATGPT.Arquivos brasileiros de cirurgia digestiva : ABCD = Brazilian archives of digestive surgery · 2023Pooled it
- Methodological approaches to measuring the incidence of unplanned emergency department presentations by cancer patients receiving systemic anti-cancer therapy: a systematic review.BMC medical research methodology · 2022Pooled it
- "Let's get the best quality research we can": public awareness and acceptance of consent to use existing data in health research: a systematic review and qualitative study.BMC medical research methodology · 2013Pooled it
- Visual Biofeedback (VB) through Trans-Perineal Ultrasound (TPU) during the active second stage of labor to improve maternal childbirth satisfaction: protocol of a randomized controlled trial.BMC pregnancy and childbirth · 2026Trial
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- Professionally designed information materials and telephone reminders improved consent response rates: evidence from an RCT nested within a cohort study.Journal of clinical epidemiology · 2015Trial
- Participant recruitment in sensitive surveys: a comparative trial of 'opt in' versus 'opt out' approaches.BMC medical research methodology · 2013Trial
- Consent to Medical Data Processing Among Adult Primary Care Patients: Associations with Vaccination Behaviour and Healthcare Trust.Healthcare (Basel, Switzerland) · 2026Article
- Dutch-TIMELINESS: optimising choledocholithiasis treatment in the Netherlands - protocol of a national implementation project.BMJ open · 2026Article
- Requirement for written informed consent and selection bias in a chart-review prostate cancer study.American journal of epidemiology · 2026Article
- Vietnamese University Students' Perceptions and Attitudes Toward Participation in Clinical Research: Mixed Methods Study.Journal of participatory medicine · 2026Article
- The patterns of relapse and abstinence: using machine learning to identify a multidimensional signature of long-term outcome after inpatient alcohol withdrawal treatment.Frontiers in psychiatry · 2026Article
- Traumatic brain injury and mortality in older adults with and without pre-injury dementia.Age and ageing · 2025Article
- Disentangling informing participants from obtaining their consent.Learning health systems · 2025Article
- The Ethics of Informed Consent for Data Registries: Moving Beyond Moral Minimalism to the High Ground.Bioethics · 2025Article
- Ten quick tips for protecting health data using de-identification and perturbation of structured datasets.PLoS computational biology · 2025Article
64 more citing papers are in PubMed but not listed here.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
5 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
objectivesTo determine whether informed consent introduces selection bias in prospective observational studies using data from medical records, and consent rates for such studies.
designSystematic review. DATA SOURCES: Embase, Medline, and the Cochrane Library up to March 2008, reference lists from pertinent articles, and searches of electronic citations. STUDY SELECTION: Prospective observational studies reporting characteristics of participants and non-participants approached for informed consent to use their medical records. Studies were selected independently in duplicate; a third reviewer resolved disagreements. DATA EXTRACTION: Age, sex, race, education, income, or health status of participants and non-participants, the participation rate in each study, and susceptibility of these calculations to threats of selection and reporting bias.
resultsOf 1650 citations 17 unique studies met inclusion criteria and had analysable data. Across all outcomes there were differences between participants and non-participants; however, there was a lack of consistency in the direction and the magnitude of effect. Of 161 604 eligible patients, 66.9% consented to use of data from their medical records.
conclusionsSignificant differences between participants and non-participants may threaten the validity of results from observational studies that require consent for use of data from medical records. To ensure that legislation on privacy does not unduly bias observational studies using medical records, thoughtful decision making by research ethics boards on the need for mandatory consent is necessary.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
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.