Table 1

 Alphabetical list of biases, indicating their type and the design where they can occur

Specific name of biasGroup of biasSubgroup of bias (next level to specific name)Type of design affected
Allocation of intervention biasExecution of an interventionTrial
Apprehension biasInformation biasObserver biasAll studies
Ascertainment biasSelection biasInappropriate definition of the eligible populationObservational study
Berkson’s biasSelection biasInappropriate definition of the eligible populationHospital based case-control study
Centripetal biasSelection biasHealthcare access biasObservational study
Citation biasSelection biasLack of accuracy of sampling frameSystematic review/meta-analysis
Competing risksSelection biasAscertainment biasAll studies
Compliance biasExecution of an interventionTrial
Confounding by groupConfoundingEcological study
Confounding by indicationConfoundingCase-control study, cohort study
Contamination biasExecution of an interventionTrial, mainly community trials
Detection biasSelection biasUneven diagnostic procedures in the target populationCase-control study
Detection biasInformation biasMisclassification biasCohort study
Diagnostic/treatment access biasSelection biasHealthcare access biasObservational study
Diagnostic suspicion biasSelection biasDetection biasCase-control study
Diagnostic suspicion biasInformation biasDetection biasCohort study
Differential maturingTrial
Differential misclassification biasInformation biasMisclassification biasAll studies
Dissemination biasSelection biasLack of accuracy of sampling frameSystematic review/meta-analysis
Ecological fallacyInformation biasEcological study
Exclusion biasSelection biasInappropriate definition of the eligible populationCase-control study
Exposure suspicion biasInformation biasRecall biasCase-control study
Family aggregation biasInformation biasReporting biasObservational study
Friend control biasSelection biasInappropriate definition of the eligible populationCase-control study
Hawthorne effectInformation biasTrial
Healthcare access biasSelection biasAscertainment biasObservational study
Healthy volunteer biasSelection biasNon-response biasObservational study
Healthy worker effectSelection biasInappropriate definition of the eligible populationCohort study (mainly retrospective)
Incidence-prevalence bias (synonym of Neyman bias)
Inclusion biasSelection biasInappropriate definition of the eligible populationHospital based case-control study
Lack of intention to treat analysisRandomised trial
Language biasSelection biasInappropriate definition of the eligible populationSystematic review/meta-analysis
Lead-time biasInformation biasScreening study
Length biased samplingSelection biasAscertainment biasCross sectional study, screening
Losses/withdrawals to follow upSelection biasDuring study implementationCohort study, trial
Mimicry biasSelection biasDetection biasCase-control study
Mimicry biasInformation biasDetection biasCohort study
Misclassification biasInformation biasAll studies
Missing information in multivariable analysisSelection biasDuring study implementationAll studies (mainly retrospective)
Mode for mean biasInformation biasReporting biasAll studies
Neyman biasSelection biasAscertainment biasCross sectional study, case-control study with prevalent cases
Non-differential misclassification biasInformation biasMisclassification biasAll studies
Non-random sampling biasSelection biasLack of accuracy of sampling frameObservational study
Non-response biasSelection biasDuring study implementationObservational study
Obsequiousness biasInformation biasReporting biasAll studies
Observer expectation biasInformation biasObserver biasAll studies
Observer/interviewer biasInformation biasMisclassification biasAll studies
OvermatchingSelection biasInappropriate definition of the eligible populationCase-control study
Participant expectation biasInformation biasRecall biasTrial
Popularity biasSelection biasHealthcare access biasObservational study
Post hoc analysisSelection biasPublication biasSystematic review/meta-analysis
Protopathic biasInformation biasObservational study
Publication biasSelection biasLack of accuracy of sampling frameSystematic review/meta-analysis
Purity diagnostic biasSelection biasSpectrum biasValidity of diagnostic tests
Recall biasInformation biasMisclassification biasAll studies
Referral filter biasSelection biasHealthcare access biasObservational study
Regression dilution biasInformation biasRegression to the meanCohort study, trial
Regression to the meanInformation biasCohort study, trial
Relative control biasSelection biasInappropriate definition of the eligible populationCase-control study
Reporting biasInformation biasMisclassification biasAll studies
Rumination biasInformation biasRecall biasCase-control study, retrospective cohort study
Selective survival bias (synonym of Neyman bias)
Sick quitter biasInformation biasProtopathic biasObservational study
Spectrum biasSelection biasAscertainment biasValidity of diagnostic tests (mainly case-control study)
Survivor treatment selection biasSelection biasAscertainment biasCohort study (mainly retrospective)
Susceptibility bias (synonym of confounding)
Telephone random sampling biasSelection biasNon-random sampling biasObservational study
Temporal ambiguityInformation biasCross sectional study, ecological study
Unacceptable disease/exposureInformation biasReporting biasObservational study
Underreporting biasInformation biasReporting biasObservational study
Unmasking—detection signal—biasSelection biasDetection biasCase-control study
Verification bias (synonym of work up bias)
Will Rogers phenomenonInformation biasPrognostic (mainly cohort) study
Work up biasInformation biasValidity of diagnostic test (retrospective study)