Where the methods of systematic review change from the those stated in the protocol, this should be documented and justified in the final report. This problem is addressed in PRISMA 2020, AMSTAR 2 and MECIR.
Articles that support this problem:
Outcome reporting bias in Cochrane systematic reviews: a cross-sectional analysis
2020 : Bmj open
The fate of urological systematic reviews registered in PROSPERO
2019 : World journal of urology
Comparison of non-Cochrane systematic reviews and their published protocols: differences occurred frequently but were seldom explained
2019 : Journal of clinical epidemiology
Publishing protocols of systematic reviews: comparing what was done to what was planned
2002 : Jama
Bias due to changes in specified outcomes during the systematic review process
2010 : Plos one
Discrepancies in outcome reporting exist between protocols and published oral health Cochrane systematic reviews
2015 : Plos one
Bias due to selective inclusion and reporting of outcomes and analyses in systematic reviews of randomised trials of healthcare interventions
2014 : The cochrane library
Selective reporting of outcomes in randomised controlled trials in systematic reviews of cystic fibrosis
2013 : Bmj open
Methodological Quality of Systematic Reviews on Bodyweight Management Strategies for Children and Adolescents
2023 : Medicine & science in sports & exercise
Evidence Mapping Based on Systematic Reviews of Cognitive Behavioral Therapy for Neuropathic Pain
2023 : Neural plasticity
Tripterygium wilfordii Hook. f. Preparations for Rheumatoid Arthritis: An Overview of Systematic Reviews
2022 : Evidence-based complementary & alternative medicine: ecam
The Campbell Collaboration's systematic review of school-based anti-bullying interventions does not meet mandatory methodological standards
2022 : Systematic reviews
Caution should be exercised when assessing ivermectin for the treatment of COVID-19 in systematic reviews
2022 : Reviews in medical virology
Most Cochrane systematic reviews and protocols did not adhere to the Cochrane's risk of bias 2.0 tool
2023 : Revista da associacao medica brasileira
Examining the state, quality and strength of the evidence in the research on built environments and physical activity among adults: An overview of reviews from high income countries
2022 : Health & place
Is the quality of systematic reviews influenced by prospective registration: a methods review of systematic musculoskeletal physical therapy reviews
2022 : Journal of manual & manipulative therapy
Prescription drug monitoring programs evaluation: A systematic review of reviews
2023 : Drug & alcohol dependence
Acupuncture and Related Therapies for Chronic Urticaria: A Critical Overview of Systematic Reviews
2022 : Evidence-based complementary & alternative medicine: ecam
Assessing the magnitude of changes from protocol to publication-a survey on Cochrane and non-Cochrane Systematic Reviews
2023 : Peerj