Epidemiology and Reporting Characteristics of Systematic Reviews of Biomedical Research: A Cross-Sectional Study

Summary

Background Systematic reviews (SRs) can help decision makers interpret the deluge of published biomedical literature. However, a SR may be of limited use if the methods used to conduct the SR are flawed, and reporting of the SR is incomplete. To our knowledge, since 2004 there has been no cross-sectional study of the prevalence, focus, and completeness of reporting of SRs across different specialties. Therefore, the aim of our study was to investigate the epidemiological and reporting characteristics of a more recent cross-section of SRs. Methods and Findings We searched MEDLINE to identify potentially eligible SRs indexed during the month of February 2014. Citations were screened using prespecified eligibility criteria. Epidemiological and reporting characteristics of a random sample of 300 SRs were extracted by one reviewer, with a 10% sample extracted in duplicate. We compared characteristics of Cochrane versus non-Cochrane reviews, and the 2014 sample of SRs versus a 2004 sample of SRs. We identified 682 SRs, suggesting that more than 8,000 SRs are being indexed in MEDLINE annually, corresponding to a 3-fold increase over the last decade. The majority of SRs addressed a therapeutic question and were conducted by authors based in China, the UK, or the US; they included a median of 15 studies involving 2,072 participants. Meta-analysis was performed in 63% of SRs, mostly using standard pairwise methods. Study risk of bias/quality assessment was performed in 70% of SRs but was rarely incorporated into the analysis (16%). Few SRs (7%) searched sources of unpublished data, and the risk of publication bias was considered in less than half of SRs. Reporting quality was highly variable; at least a third of SRs did not report use of a SR protocol, eligibility criteria relating to publication status, years of coverage of the search, a full Boolean search logic for at least one database, methods for data extraction, methods for study risk of bias assessment, a primary outcome, an abstract conclusion that incorporated study limitations, or the funding source of the SR. Cochrane SRs, which accounted for 15% of the sample, had more complete reporting than all other types of SRs. Reporting has generally improved since 2004, but remains suboptimal for many characteristics. Conclusions An increasing number of SRs are being published, and many are poorly conducted and reported. Strategies are needed to help reduce this avoidable waste in research.

Key Points

• 1Systematic reviews have become more prevalent, with over 8000 indexed annually in MEDLINE
• 2Many systematic reviews lack important methodological details, impacting their utility
• 3Cochrane reviews displayed better reporting quality compared to non-Cochrane reviews
• 4The study indicates that despite improvements, reporting quality remains suboptimal
• 5Enhanced training and guidelines are recommended to reduce inconsistencies in systematic reviews

Related articles

• Absolutely. I based this on the 4th edition of Essentials of

  Absolutely. I based this on the 4th edition of Essentials of Nursing Informatics that you uploaded. The book identifies Chapter 17 as “Theories, Models, and Frameworks” and Chapter 32 as “The Nursing

• Anatomy and Physiology of the Respiratory System

  This document provides a detailed overview of the anatomy and functions of the respiratory system, including structures, gas exchange mechanisms, and respiratory physiology. It covers both upper and lower respiratory tract components, physiological processes involved in breathing, and the impacts of various factors on respiratory health.

• Blood Vessels and Circulatory System Functions

  This document provides an extensive overview of blood vessel functions, classifications, structures, and the circulatory system's physiology. It details systemic and pulmonary circulation, highlighting the anatomy and roles of various arteries and veins.

• Functions and Anatomy of the Lymphatic and Immune Systems

  This document provides an overview of the lymphatic system's functions, anatomy, and its role in immunity, detailing structures such as lymphatic vessels, nodes, and organs. It also covers innate and adaptive immunity, including responses to foreign substances and the production of immune cells.

• The Endocrine System

  This document provides a comprehensive overview of the Endocrine System, detailing the various glands, hormones they secrete, and their effects on bodily functions. It explores the roles of each gland, the hormones involved, and the feedback mechanisms that regulate hormone levels.