Background Recently there has been a significant increase in the number of systematic reviews addressing questions of prevalence. Key features of a systematic review include the creation of an a priori protocol, clear inclusion criteria, a structured and systematic search process, critical appraisal of studies, and a formal process of data extraction followed by methods to synthesize, or combine, this data. Currently there exists no standard method for conducting critical appraisal of studies in systematic reviews of prevalence data. Methods A working group was created to assess current critical appraisal tools for studies reporting prevalence data and develop a new tool for these studies in systematic reviews of prevalence. Following the development of this tool it was piloted amongst an experienced group of sixteen healthcare researchers. Results The results of the pilot found that this tool was a valid approach to assessing the methodological quality of studies reporting prevalence data to be included in systematic reviews. Participants found the tool acceptable and easy to use. Some comments were provided which helped refine the criteria. Conclusion The results of this pilot study found that this tool was well-accepted by users and further refinements have been made to the tool based on their feedback. We now put forward this tool for use by authors conducting prevalence systematic reviews.

The systematic review of evidence is the research method which underpins the traditional approach to evidence-based healthcare. There is currently no uniform methodology for conducting a systematic review of association (etiology). This study outlines and describes the Joanna Briggs Institute's approach and guidance for synthesizing evidence related to association with a predominant focus on etiology and contributes to the emerging field of systematic review methodologies. It should be noted that questions of association typically address etiological or prognostic issues.The systematic review of studies to answer questions of etiology follows the same basic principles of systematic review of other types of data. An a priori protocol must inform the conduct of the systematic review, comprehensive searching must be performed and critical appraisal of retrieved studies must be carried out.The overarching objective of systematic reviews of etiology is to identify and synthesize the best available evidence on the factors of interest that are associated with a particular disease or outcome. The traditional PICO (population, interventions, comparators and outcomes) format for systematic reviews of effects does not align with questions relating to etiology. A systematic review of etiology should include the following aspects: population, exposure of interest (independent variable) and outcome (dependent variable).Studies of etiology are predominantly explanatory or predictive. The objective of reviews of explanatory or predictive studies is to contribute to, and improve our understanding of, the relationship of health-related events or outcomes by examining the association between variables. When interpreting possible associations between variables based on observational study data, caution must be exercised due to the likely presence of confounding variables or moderators that may impact on the results.As with all systematic reviews, there are various approaches to present the results, including a narrative, graphical or tabular summary, or meta-analysis. When meta-analysis is not possible, a set of alternative methods for synthesizing research is available. On the basis of the research question and objectives, narrative, tabular and/or visual approaches can be used for data synthesis. There are some special considerations when conducting meta-analysis for questions related to risk and correlation. These include, but are not limited to, causal inference.Systematic review and meta-analysis of studies related to etiology is an emerging methodology in the field of evidence synthesis. These reviews can provide useful information for healthcare professionals and policymakers on the burden of disease. The standardized Joanna Briggs Institute approach offers a rigorous and transparent method to conduct reviews of etiology.

Background: Healthcare services, in many countries, are increasingly being provided by cadres not trained as physicians, and these substitute health workers are referred to as mid-level health providers (MLHPs). The objective of this study was to rapidly synthesise evidence on the effectiveness of MLHPs involved in the delivery of healthcare, with a perspective on low- and middle-income countries. Methods: The review team performed an overview of systematic reviews assessing various outcomes for participants receiving care from MLHPs. The team evaluated systematic reviews for methodological quality and certainty of the evidence. Also, the review team consulted relevant stakeholders in India. Results: The final report included seven systematic reviews, with six assessed as moderate to high methodological quality. Mortality outcomes concerning pregnancy and childbirth care services showed no significant differences in care provided by MLHPs when compared with doctors. Pregnancy care provided by midwives was found to improve the quality of care slightly. The risk of failure or incomplete abortion for surgical abortion procedures provided by MLHPs was twice when compared to the procedures provided by doctors. Moderate to high certainty evidence showed that initiation and maintenance of antiretroviral therapy for HIV-infected patients by a nurse or clinical officer slightly reduced mortality. High certainty evidence showed that chronic disease management by non-medical prescribers reduced some important physiological measures compared to medical prescribing by doctors. Conclusions: To date, this is the first rapid overview of the evidence on MLHPs. Low-quality evidence suggests that MLHPs might be suitable to deliver quality pregnancy care. Moderate and high-quality evidence from trials suggests that MLHPs are helpful for chronic disease management and initiation and maintenance of antiretroviral therapy in people with HIV/AIDS. However, the roles and subsequent training and regulation of MLHPs might be different for different care domains.