An evaluation of EMBASE within the NHS: findings of the Database Access Project working partnership to extend the knowledge base of healthcare

Optimal literature search for systematic reviews in surgery

BACKGROUND

The aim of the present study was to determine empirically which electronic databases contribute best to a literature search in surgical systematic reviews.

METHODS

For ten published systematic reviews, the systematic literature searches were repeated in the databases MEDLINE, Web of Science, CENTRAL, and EMBASE. On the basis of these reviews, a gold standard set of eligible articles was created. Recall (%), precision (%), unique contribution (%), and numbers needed to read (NNR) were calculated for each database, as well as for searches of citing references and of the reference lists of related systematic reviews (hand search).

RESULTS

CENTRAL yielded the highest recall (88.4%) and precision (8.3%) for randomized controlled trials (RCT), MEDLINE for non-randomized studies (NRS; recall 92.6%, precision 5.2%). The most effective combination of two databases plus hand searching for RCT was MEDLINE/CENTRAL (98.6% recall, NNR 97). Adding EMBASE marginally increased the recall to 99.3%, but with an NNR of 152. For NRS, the most effective combination was MEDLINE/Web of Science (99.5% recall, NNR 60).

CONCLUSIONS

For surgical systematic reviews, the optimal literature search for RCT employs MEDLINE and CENTRAL. For surgical systematic reviews of NRS, Web of Science instead of CENTRAL should be searched. EMBASE does not contribute substantially to reviews with a surgical intervention.

Basics of systematic reviews and meta-analyses for the nephrologist

Renal practitioners are expected to apply the best available evidence from rigorous scientific research to clinical decision-making and also for policy-making for those involved. Advances in information technology and unprecedented access to data have simplified the process for the search of best available evidence to guide practice. However, it is challenging to cope with the increasing volume of publications in nephrology and other areas of medicine. Accordingly, systematic reviews and meta-analysis have greatly facilitated best practice and effective clinical decision-making. Conducting a systematic review/meta-analysis involves a number of steps that start with protocol development and research question formulation, design and study selection criteria, followed by retrieval of potentially relevant studies, selection of those studies to be included and evaluation of a study's risk of bias. Systematic reviews and meta-analyses have both strengths and weaknesses. Many of the perceived limitations of meta-analysis are not inherent in the methodology, but actually represent deficits in the conduct or reporting of individual primary studies. With the continuous proliferation of published renal clinical studies, such publications will continue to be an important resource for clinicians and researchers in nephrology. It is therefore important for nephrologists to keep abreast of developments in this field, which requires some knowledge about how these studies are conducted, reported and how to appraise them for application to clinical practice or policy-making.

Monitoring outcomes with relational databases: Does it improve quality of care?

There are 3 key ingredients in improving quality of medial care: 1) using a scientific process of improvement, 2) executing the process at the lowest possible level in the organization, and 3) measuring the results of any change reliably. Relational databases when used within these guidelines are of great value in these efforts if they contain reliable information that is pertinent to the project and used in a scientific process of quality improvement by a front line team. Unfortunately, the data are frequently unreliable and/or not pertinent to the local process and is used by persons at very high levels in the organization without a scientific process and without reliable measurement of the outcome. Under these circumstances the effectiveness of relational databases in improving care is marginal at best, frequently wasteful and has the potential to be harmful. This article explores examples of these concepts.