Failure to address missing outcome data in analyses

This problem is addressed in PRISMA 2009, PRISMA 2020 and MECIR. Some missing outcome data is expected in most systematic reviews due to reporting biases or word count restrictions in published papers therefore systematic review authors should plan how they will deal with missing outcome data. For example, contacting study authors or imputation. The Risk Of Bias due to Missing Evidence in a synthesis (ROB-ME) is a tool for this scenario.

Articles that support this problem:

Can Cochrane Reviews in controversial areas be biased? A sensitivity analysis based on the protocol of a Systematic Cochrane Review on low-level laser therapy in osteoarthritis

2005 : Photomedicine and laser therapy

Reporting, handling and assessing the risk of bias associated with missing participant data in systematic reviews: a methodological survey

2015 : Bmj open

Can a core outcome set improve the quality of systematic reviews?–a survey of the Co-ordinating Editors of Cochrane Review Groups

2013 : Trials

Effects of drop-out on efficacy estimates in five Cochrane reviews of popular antipsychotics for schizophrenia

2012 : Acta psychiatrica scandinavica

Reporting and handling missing outcome data in mental health: a systematic review of Cochrane systematic reviews and meta‐analyses

2015 : Research synthesis methods

Missing binary data extraction challenges from Cochrane reviews in mental health and Campbell reviews with implications for empirical research

2017 : Research synthesis methods

Contacting of authors modified crucial outcomes of systematic reviews but was poorly reported, not systematic, and produced conflicting results

2019 : Journal of clinical epidemiology

A systematic survey shows that reporting and handling of missing outcome data in networks of interventions is poor

2018 : Bmc medical research methodology

Systematic reviews do not adequately report or address missing outcome data in their analyses: a methodological survey

2018 : Journal of clinical epidemiology

Systematic reviewers commonly contact study authors but do so with limited rigor

2009 : Journal of clinical epidemiology

Potential impact of missing outcome data on treatment effects in systematic reviews: imputation study

2020 : Bmj

The impact of outcome reporting bias in randomised controlled trials on a cohort of systematic reviews

2010 : Bmj

Assessment of publication bias and outcome reporting bias in systematic reviews of health services and delivery research: A meta-epidemiological study

2020 : Plos one

Reporting and Handling of Missing Participant Data in Systematic Reviews of Kidney Transplant Studies

2021 : Transplantation

Improving prediction model systematic review methodology: Letter to the Editor

2021 : Translational sports medicine

Missing Data in Systematic Reviews and Meta-Analysis

2022 : Pediatric critical care medicine