Systematic reviews were noted to be of poor quality (reporting or methodological) prior to the availibility of established reporting and methodological guidelines.
Articles that support this problem:
Need for quality improvement in renal systematic reviews
2008 : Clinical journal of the american society of nephrology
Methodological quality of systematic reviews analyzing the use of laser therapy in restorative dentistry
2010 : Lasers in medical science
The methodological quality of systematic reviews published in high‐impact nursing journals: a review of the literature
2014 : Journal of clinical nursing
Peer Reviewed: Quality of Systematic Reviews of Observational Nontherapeutic Studies
2010 : Preventing chronic disease
A review of methodological quality of systematic reviews on multiple pregnancies
2006 : Journal of obstetrics & gynaecology
Methods and reporting of systematic reviews of comparative accuracy were deficient: a methodological survey and proposed guidance
2020 : Journal of clinical epidemiology
Evaluation of the methodological quality of systematic reviews of health status measurement instruments
2009 : Quality of life research
The collaboration and reporting quality of social welfare systematic reviews in the Campbell Collaboration online library
2019 : Health & quality of life outcomes
Assessment of the quality of reporting in abstracts of systematic reviews with meta-analyses in periodontology and implant dentistry
2014 : Journal of periodontal research
Dissemination bias in systematic reviews of animal research: a systematic review
2014 : Plos one
An evaluation of epidemiological and reporting characteristics of complementary and alternative medicine (CAM) systematic reviews (SRs)
2013 : Plos one
Cochrane systematic reviews of Chinese herbal medicines: an overview
2011 : Plos one
Blinded by PRISMA: are systematic reviewers focusing on PRISMA and ignoring other guidelines?
2014 : Plos one
The "quality" of JBI qualitative research synthesis: a methodological investigation into the adherence of meta-aggregative systematic reviews to reporting standards and methodological guidance
2021 : Jbi evidence synthesis
Quality, methods, and recommendations of systematic reviews on measures of evidence-based practice: an umbrella review
2022 : Jbi evidence synthesis
Synthesis methods other than meta-analysis were commonly used but seldom specified: survey of systematic reviews
2023 : Journal of clinical epidemiology
Caution should be exercised when assessing ivermectin for the treatment of COVID-19 in systematic reviews
2022 : Reviews in medical virology
Causal language use in systematic reviews of observational studies is often inconsistent with intent: a systematic survey
2022 : Journal of clinical epidemiology
A Cross-Sectional Study Based on Forty Systematic Reviews of Foods with Function Claims (FFC) in Japan: Quality Assessment Using AMSTAR 2
2023 : Nutrients