Bias in 2.1. Was selection of participants into the (or into the Y / PY / PN / N / NI [Description] selection of analysis) based on variables measured after the start of the participants exposure? into the study If N or PN to 2.1 go to 2.4 2.2. If Y/PY to 2.1: Were the post-exposure variables that Y / PY / PN / N / NI [Description] influenced selection associated with exposure? 2.3. If Y/PY to 2.2: Were the post-exposure variables that NA / Y / PY / PN / N / NI [Description] influenced eligibility selection influenced by the outcome or a cause of the outcome? 2.4 Do start of follow-up and start of exposure coincide for most NA / Y / PY / PN / N / NI [Description] participants? 2.5 If Y/PY to 2.2 and 2.3, or N/PN to 2.4: Were adjustment NA / Y / PY / PN / N / NI [Description] techniques used that are likely to correct for the presence of selection biases? Risk of bias judgement Low / Moderate / Serious / [Support for judgement] Critical / NI Optional: What is the predicted direction of bias due to selection Favors experimental / Favors [Rationale] comparator / Towards null of participants into the study? /Away from null / Unpredictable Bias in 3.1 Is exposure status well defined? Y / PY / PN / N / NI [Description] classification 3.2 Did entry into the study begin with start of the exposure? Y / PY / PN / N / NI [Description] of exposures 3.3 Was information used to define exposure status recorded prior Y / PY / PN / N / NI [Description] to outcome assessment? 3.4 classification of exposure status have been affected by Y / PY / PN / N / NI [Description] knowledge of the outcome or risk of the outcome? 3.5 Were exposure assessment methods robust (including Y / PY / PN / N / NI [Description] methods used to data)? Low / Moderate / Serious / [Support for judgement] Risk of bias judgement Critical / NI
Bias in selection of participants into the study 2.1. Was selection of participants into the (or into the analysis) based on variables measured after the start of the exposure? If N or PN to 2.1 go to 2.4 Y / PY / PN / N / NI [Description] 2.2. If Y/PY to 2.1: Were the post-exposure variables that influenced selection associated with exposure? Y / PY / PN / N / NI [Description] 2.3. If Y/PY to 2.2: Were the post-exposure variables that influenced eligibility selection influenced by the outcome or a cause of the outcome? NA / Y / PY / PN / N / NI [Description] 2.4 Do start of follow-up and start of exposure coincide for most participants? NA / Y / PY / PN / N / NI [Description] 2.5 If Y/PY to 2.2 and 2.3, or N/PN to 2.4: Were adjustment techniques used that are likely to correct for the presence of selection biases? NA / Y / PY / PN / N / NI [Description] Risk of bias judgement Low / Moderate / Serious / Critical / NI [Support for judgement] Optional: What is the predicted direction of bias due to selection of participants into the study? Favors experimental / Favors comparator / Towards null /Away from null / Unpredictable [Rationale] Bias in classification of exposures 3.1 Is exposure status well defined? Y / PY / PN / N / NI [Description] 3.2 Did entry into the study begin with start of the exposure? Y / PY / PN / N / NI [Description] 3.3 Was information used to define exposure status recorded prior to outcome assessment? Y / PY / PN / N / NI [Description] 3.4 classification of exposure status have been affected by knowledge of the outcome or risk of the outcome? Y / PY / PN / N / NI [Description] 3.5 Were exposure assessment methods robust (including methods used to data)? Y / PY / PN / N / NI [Description] Risk of bias judgement Low / Moderate / Serious / Critical / NI [Support for judgement]
Risk_of_bias_preliminary_for_exposures_template_Jul2017.docx