What is the evidence that postgraduate teaching in evidence based medicine changes anything? A systematic review

OBJECTIVE

To evaluate the effects of standalone versus clinically integrated teaching in evidence based medicine on various outcomes in postgraduates.

DESIGN

Systematic review of randomised and non-randomised controlled trials and before and after comparison studies.

DATA SOURCES

Medline, Embase, ERIC, Cochrane Library, DARE, HTA database, Best Evidence, BEME, and SCI.

STUDY SELECTION

23 studies: four randomised trials, seven non-randomised controlled studies, and 12 before and after comparison studies. 18 studies (including two randomised trials) evaluated a standalone teaching method, and five studies (including two randomised trials) evaluated a clinically integrated teaching method.

MAIN OUTCOME MEASURES

Knowledge, critical appraisal skills, attitudes, and behaviour.

RESULTS

Standalone teaching improved knowledge but not skills, attitudes, or behaviour. Clinically integrated teaching improved knowledge, skills, attitudes, and behaviour.

CONCLUSION

Teaching of evidence based medicine should be moved from classrooms to clinical practice to achieve improvements in substantial outcomes.

Quality of brief guidelines produced by professional bodies: a study of the 'green-top' guidelines by the UK Royal College of Obstetricians and Gynaecologists

Clinicians ignore lengthy guidelines and prefer pocket cards and concise pamphlets. However, brevity in guidelines may lead to deficiency in quality. Our objective, therefore, was to examine the quality of brief guidelines produced by professional bodies, using those produced by the UK Royal College of Obstetricians and Gynaecologists (RCOG) as an example. We assessed all 22 'green-top' guidelines, produced by September 2002, for quality using a validated 37-item appraisal instrument. This instrument evaluated the guidelines on three dimensions, namely rigour of development, context and content and applicability. Ten (45%), 18 (82%) and five (23%) of the 22 guidelines met at least half the quality criteria for rigour of development, context and content and applicability, respectively. We conclude that the brief guidelines were deficient in several specific quality items, particularly those in the applicability dimension. Guideline developers need to achieve the higher quality standards expected of professional bodies.

Accuracy of cervical transvaginal sonography in predicting preterm birth: a systematic review

This review investigates the accuracy with which transvaginal cervical sonography predicts spontaneous preterm birth. Published studies were identified without language restrictions through nine different databases and manual searching of bibliographies of known primary and review articles. Studies were selected if they undertook antenatal transvaginal sonographic cervical assessment among a population of pregnant women with known gestational age of delivery. There were 46 primary articles, which included a total of 31,577 women, consisting of 33 studies in asymptomatic and 13 studies in symptomatic women. Data were extracted for the studies' characteristics and quality. Accuracy data were used to form 2 x 2 contingency tables for various cervical length measurements with birth before 32, 34 and 37 weeks' gestation as the reference standards. Data were stratified according to singleton or twin pregnancy, gestational age at testing, cervical length threshold, and the various reference standards, and were pooled to produce summary estimates of likelihood ratios (LRs). Our review showed that transvaginal cervical sonography identifies women who are at higher risk of spontaneous preterm birth, although there was a wide variation amongst studies with respect to gestational age at testing, definition of threshold of abnormality and definition of reference standard. The most commonly reported sub-group was testing of asymptomatic women at < 20 weeks' gestation using a threshold cervical length of 25 mm with spontaneous preterm birth before 34 weeks' gestation as the reference standard. The summary LR+ for this group was 6.29 (95% CI, 3.29-12.02), with corresponding LR- of 0.79 (95% CI, 0.65-0.95). Both cervical length measurement and funneling, whether alone or in combination, appear to be useful (depending on the threshold chosen to define the abnormality) in predicting spontaneous preterm birth in asymptomatic women. For symptomatic women there was a paucity of data, although the degree of funneling appeared to be predictive of spontaneous preterm birth.

Long term safety of fluoroscopically guided selective salpingography and tubal catheterization

BACKGROUND

The irradiation of the ovaries of reproductive age women during fluoroscopically guided selective salpingography and tubal catheterization has raised concern about the safety of the procedure. In addition to the risk of cancer induction, which exists with the irradiation of all tissues, with the gonads, the induction of hereditary disorders is possible. The objective of this study was to estimate these risks and present them in a clinically meaningful way.

METHODS

Retrospective analysis was undertaken of 366 consecutive cases of selective salpingography and tubal catheterization performed at the Birmingham Women's Hospital, UK. The radiation doses of different types of procedure were compared with the background annual radiation dose. The risks of cancer and genetic disorders induction were calculated using conversion coefficients published by the International Commission on Radiological Protection.

RESULTS

The radiation dose women were exposed to during selective salpingography and tubal catheterization under fluoroscopic guidance was a fraction of the background annual radiation dose. The excess lifetime risks of cancer and hereditary disorders were in the order of four to 13 and two to six per million procedures respectively.

CONCLUSIONS

The long term risks of selective salpingography and tubal catheterization under fluoroscopic guidance are low.

Medical journals and effective dissemination of health research

Clinical medical journals have not been effective in meeting the information needs of practitioners and bridging the gap between clinical research and practice. The slow adoption of results of clinical research is at least partly due to the failure of clinical journals to disseminate information in a way that would motivate practitioners to change practice. Although implementation is primarily a local process, medical journals are in a unique position to advance implementation by modifying their focus and adjusting their contents. Strategies that may be useful include publication of pre-appraised evidence summaries and 'clinical bottom-lines' and giving importance to systematic reviews and large evaluative research articles as they represent higher levels of evidence and have greater potential to change practice. Clinical journals should encourage researchers to consider how and by whom the findings will be used and provide information on implications for implementation such as possible strategies that may work, cost-effectiveness, side-effects and potential barriers to implementation. Medical journal publishers should explore ways to cooperate so that findings of landmark clinical trials could be shared thus reducing the 'scatter' of medical information. Electronic media offers numerous advantages such as quick accessibility and linking of information, and medical journals should capitalize on such innovations. There is a paradigm shift in health care practice as evidence is consciously and explicitly incorporated into individual patient care. Medical journals need to change to reflect this change in practice and provide practitioners with valid and relevant information.

Aspirin for the prevention of preeclampsia in women with abnormal uterine artery Doppler: a meta-analysis

OBJECTIVE

To determine the effectiveness of aspirin to prevent preeclampsia in women identified as high risk for preeclampsia by an abnormal second-trimester uterine artery Doppler examination.

DATA SOURCES

Searches were conducted in MEDLINE, Embase, the Cochrane Controlled Trials Register, and Science Citation Index for randomized trials published from 1966 to 2000, using the following medical subject headings and key words: "aspirin," "antiplatelet*," "salicyl*," "acetylsalicyl*," "platelet aggregation inhibitors," "ultrasonography," "ultraso*," and "Doppler."

STUDY SELECTION

We included all randomized trials that evaluated the effectiveness of aspirin compared with placebo or no treatment in women with an abnormal uterine artery Doppler and that reported clinically relevant perinatal and maternal outcomes. Study selection, quality assessment, and data extraction were performed in duplicate.

TABULATION, INTEGRATION, AND RESULTS

There were five relevant trials. Pooling of results from these trials showed a significant benefit of aspirin in reducing preeclampsia (odds ratio [OR] 0.55, 95% confidence interval [CI] 0.32, 0.95). The baseline risk of preeclampsia in women with abnormal uterine artery Doppler was 16%, and the number of women needed to be treated with aspirin to prevent one case of preeclampsia was 16 (95% CI 8, 316). Women on aspirin had babies who were on average 82 g heavier than controls, but this result did not reach statistical significance (weighted mean difference 81.5, 95% CI 40.27, 203.27).

CONCLUSION

Uterine artery Doppler assessment identifies high-risk women in whom aspirin therapy results in a significant reduction in preeclampsia.

Critical appraisal in clinical practice: sometimes irrelevant, occasionally invalid

A core activity of evidence-based practice is the search for and appraisal of evidence on specific clinical issues. Clinicians vary in their competence in this process; we therefore developed a 16-item checklist for quality of content (relevance and validity) and presentation (useability, attribution, currency and contact details). This was applied to a set of 55 consecutive appraisals conducted by clinicians and posted at a web-based medical journal club site. Questions were well formulated in 51/55 (92%) of the appraisals. However, 22% of appraisals missed the most relevant articles to answer the clinical question. Validity of articles was well appraised, with methodological information and data accurately extracted in 84% and accurate conversion to clinically meaningful summary statistics in 87%. The appraisals were presented in a useable way with appropriate and clear bottom-lines stated in 95%. The weakest link in production of good-quality critical appraisals was identification of relevant articles. This should be a focus for evidence-based medicine and critical appraisal skills.