A comparison of metrics and performance characteristics of different search strategies for article retrieval for a systematic review of the global epidemiology of kidney and urinary diseases

Search strategies (filters) to identify systematic reviews in MEDLINE and Embase

BACKGROUND

Bibliographic databases provide access to an international body of scientific literature in health and medical sciences. Systematic reviews are an important source of evidence for clinicians, researchers, consumers, and policymakers as they address a specific health-related question and use explicit methods to identify, appraise and synthesize evidence from which conclusions can be drawn and decisions made. Methodological search filters help database end-users search the literature effectively with different levels of sensitivity and specificity. These filters have been developed for various study designs and have been found to be particularly useful for intervention studies. Other filters have been developed for finding systematic reviews. Considering the variety and number of available search filters for systematic reviews, there is a need for a review of them in order to provide evidence about their retrieval properties at the time they were developed.

OBJECTIVES

To review systematically empirical studies that report the development, evaluation, or comparison of search filters to retrieve reports of systematic reviews in MEDLINE and Embase.

SEARCH METHODS

We searched the following databases from inception to January 2023: MEDLINE, Embase, PsycINFO; Library, Information Science & Technology Abstracts (LISTA) and Science Citation Index (Web of Science).

SELECTION CRITERIA

We included studies if one of their primary objectives is the development, evaluation, or comparison of a search filter that could be used to retrieve systematic reviews on MEDLINE, Embase, or both.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data using a pre-specified and piloted data extraction form using InterTASC Information Specialist Subgroup (ISSG) Search Filter Evaluation Checklist.

MAIN RESULTS

We identified eight studies that developed filters for MEDLINE and three studies that developed filters for Embase. Most studies are very old and some were limited to systematic reviews in specific clinical areas. Six included studies reported the sensitivity of their developed filter. Seven studies reported precision and six studies reported specificity. Only one study reported the number needed to read and positive predictive value. None of the filters were designed to differentiate systematic reviews on the basis of their methodological quality. For MEDLINE, all filters showed similar sensitivity and precision, and one filter showed higher levels of specificity. For Embase, filters showed variable sensitivity and precision, with limited study reports that may affect accuracy assessments. The report of these studies had some limitations, and the assessments of their accuracy may suffer from indirectness, considering that they were mostly developed before the release of the PRISMA 2009 statement or due to their limited scope in the selection of systematic review topics. Search filters for MEDLINE Three studies produced filters with sensitivity > 90% with variable degrees of precision, and only one of them was developed and validated in a gold-standard database, which allowed the calculation of specificity. The other two search filters had lower levels of sensitivity. One of these produced a filter with higher levels of specificity (> 90%). All filters showed similar sensitivity and precision in the external validation, except for one which was not externally validated and another one which was conceptually derived and only externally validated. Search filters for Embase We identified three studies that developed filters for this database. One of these studies developed filters with variable sensitivity and precision, including highly sensitive strategies (> 90%); however, it was not externally validated. The other study produced a filter with a lower sensitivity (72.7%) but high specificity (99.1%) with a similar performance in the external validation.

AUTHORS' CONCLUSIONS

Studies reporting the development, evaluation, or comparison of search filters to retrieve reports of systematic reviews in MEDLINE showed similar sensitivity and precision, with one filter showing higher levels of specificity. For Embase, filters showed variable sensitivity and precision, with limited information about how the filter was produced, which leaves us uncertain about their performance assessments. Newer filters had limitations in their methods or scope, including very focused subject topics for their gold standards, limiting their applicability across other topics. Our findings highlight that consensus guidance on the conduct of search filters and standardized reporting of search filters are needed, as we found highly heterogeneous development methods, accuracy assessments and outcome selection. New strategies adaptable across interfaces could enhance their usability. Moreover, the performance of existing filters needs to be evaluated in light of the impact of reporting guidelines, including the PRISMA 2009, on how systematic reviews are reported. Finally, future filter developments should also consider comparing the filters against a common reference set to establish comparative performance and assess the quality of systematic reviews retrieved by strategies.

Global, regional, and national burden of chronic kidney disease, 1990-2017: a systematic analysis for the Global Burden of Disease Study 2017

BACKGROUND

Health system planning requires careful assessment of chronic kidney disease (CKD) epidemiology, but data for morbidity and mortality of this disease are scarce or non-existent in many countries. We estimated the global, regional, and national burden of CKD, as well as the burden of cardiovascular disease and gout attributable to impaired kidney function, for the Global Burden of Diseases, Injuries, and Risk Factors Study 2017. We use the term CKD to refer to the morbidity and mortality that can be directly attributed to all stages of CKD, and we use the term impaired kidney function to refer to the additional risk of CKD from cardiovascular disease and gout.

METHODS

The main data sources we used were published literature, vital registration systems, end-stage kidney disease registries, and household surveys. Estimates of CKD burden were produced using a Cause of Death Ensemble model and a Bayesian meta-regression analytical tool, and included incidence, prevalence, years lived with disability, mortality, years of life lost, and disability-adjusted life-years (DALYs). A comparative risk assessment approach was used to estimate the proportion of cardiovascular diseases and gout burden attributable to impaired kidney function.

FINDINGS

Globally, in 2017, 1·2 million (95% uncertainty interval [UI] 1·2 to 1·3) people died from CKD. The global all-age mortality rate from CKD increased 41·5% (95% UI 35·2 to 46·5) between 1990 and 2017, although there was no significant change in the age-standardised mortality rate (2·8%, -1·5 to 6·3). In 2017, 697·5 million (95% UI 649·2 to 752·0) cases of all-stage CKD were recorded, for a global prevalence of 9·1% (8·5 to 9·8). The global all-age prevalence of CKD increased 29·3% (95% UI 26·4 to 32·6) since 1990, whereas the age-standardised prevalence remained stable (1·2%, -1·1 to 3·5). CKD resulted in 35·8 million (95% UI 33·7 to 38·0) DALYs in 2017, with diabetic nephropathy accounting for almost a third of DALYs. Most of the burden of CKD was concentrated in the three lowest quintiles of Socio-demographic Index (SDI). In several regions, particularly Oceania, sub-Saharan Africa, and Latin America, the burden of CKD was much higher than expected for the level of development, whereas the disease burden in western, eastern, and central sub-Saharan Africa, east Asia, south Asia, central and eastern Europe, Australasia, and western Europe was lower than expected. 1·4 million (95% UI 1·2 to 1·6) cardiovascular disease-related deaths and 25·3 million (22·2 to 28·9) cardiovascular disease DALYs were attributable to impaired kidney function.

INTERPRETATION

Kidney disease has a major effect on global health, both as a direct cause of global morbidity and mortality and as an important risk factor for cardiovascular disease. CKD is largely preventable and treatable and deserves greater attention in global health policy decision making, particularly in locations with low and middle SDI.

FUNDING

Bill & Melinda Gates Foundation.