Models of Information Summary, Synthesis, and Dissemination

In Clinical Medicine

Sources and Organization of Evidence-based Knowledge

Evolution of Medical Models of Information Dissemination

• Information explosion• Increase in expectations of EBM

practice• Improved access to electronic info

Evolution of Medical Models of Information Dissemination

• Market forces are driving rapid development of many new online resources to support clinical medical practice

• Limited public and foundation funds support public health resources

Comparing Info Needs in Clinical Medicine and PH Comm. Dis.

Info Need Med

PH CD

Emerging Outbreaks + +++

Emerging Practice/Program

+ +++

Published Studies(Best Evidence)

+++

++

Policies/Guidelines ++ +++

Established Knowledge +++

++

Clinical Medical Information Models

1. Research Reports:• Collections• Summaries• Critiques• Commentaries

2. Reviews, meta-analyses, guidelines

3. Comprehensive knowledge sources

Research Reports

Accessing Collections of Research Reports :

Search Tools and Alerts• Searching MEDLINE (PubMed):

– Simple search– Prepared Filters

• Alerts:– Tables of contents– Individualized content alerts

PubMed Search on Drug Resistant Salmonella

united states[mh] AND (salmonella infections[majr] OR salmonella[majr]) AND drug resistance[majr] AND (prevention and control[subheading] OR prevention OR public health OR disease outbreaks OR population surveillance OR risk factors OR prospective studies OR case-control studies OR follow-up studies OR comparative study OR pilot projects OR retrospective studies OR longitudinal studies OR infection control) AND english[lang] AND human[mh]

Research Reports

Alerts on Recently Published Literatures

Research Reports:Summaries, Critiques, and

Commentaries

• Summary: Structured, reorganization of data and conclusions; just the key points

• Critique: Criticism of methods, interpretation of findings, conclusions

• Commentary: Puts findings into context of current knowledge and practice

Research Reports:Summaries, Critiques, and

Commentaries

Medical Examples:• Journal Watch• ACP Journal Club• Annals of Internal Medicine

Public health examples:• Journal Watch Infectious Diseases• Evidence-based Health Care

Evidence-based Healthcare covers the following types of studies:

• Evaluations of financing and organization of healthcare

• Evidence-based patient and public choice • Health economics • Health technology assessment • Managing healthcare • Promotion of evidence-based clinical practice • Public health policy • Purchasing

Systematic Reviews, Meta-Analyses and

Evidence-Based Guidelines

Systematic Reviews, Meta-Analyses and

Evidence-Based Guidelines

Medical examples:• Cochrane Database of Systematic

Reviews• National Guideline Clearinghouse• Guide to Clinical Preventive Services• Guidelines authored by medical

specialty societies

Systematic Reviews, Meta-Analyses and

Evidence-Based Guidelines

Public health examples:• Cochrane Public Health topic reviews• National Guideline Clearinghouse• Guide to Community Preventive

Services• CDC Prevention Guidelines System

Systematic Review

• Thorough literature review• Explicit criteria for selecting

studies• Tables, narrative to summarize

findings• Conclusions acknowledge

strengths, weaknesses of evidence

Cochrane Database of Systematic Reviews

• Separate Public Health Group• Standardized approach to

systematic reviews• Individual or institutional

subscription required for access to full text

• About 50 reviews and many more planned

Cochrane Review Index (Ovid)

Main results: 11 trials were included with a total of 8,130 randomized participants. Preventive therapy (any anti-TB drug) versus placebo was associated with a lower incidence of active tuberculosis (RR 0.64, 95% CI 0.51 to 0.81). This benefit was more pronounced in individuals with a positive tuberculin skin test (RR 0.38, 95% CI 0.25 to 0.57) than in those who had a negative test (RR 0.83, 95% CI 0.58 to 1.18.). Limited data suggest that the initial protective effect against tuberculosis may decline over the short to medium term. Efficacy was similar for all regimens (regardless of drug type, frequency or duration of treatment). However, compared to INH monotherapy, short -course multi-drug regimens were much more likely to require discontinuation of treatment due to adverse effects. Overall, there was no evidence that preventive therapy versus placebo reduced all-cause mortality (RR 0.95, 95% CI 0.85 to 1.06), although a favourable trend was found in people with a positive tuberculin test (RR 0.80, 95% CI 0.63 to 1.02).

Conclusions:

1. Treatment of latent tuberculosis infection (LTBI) reduces the risk of active tuberculosis in HIV positive individuals with a positive tuberculin skin test.

2. The choice of regimen will depend on factors such as cost, adverse effects, adherence and drug resistance. Future studies should assess these aspects.

3. In addition, trials evaluating the long-term effects of anti-tuberculosis chemoprophylaxis and the influence of level of immunocompromise on effectiveness are needed.

Meta-analysis

• Similar to systematic review• Statistically assesses aggregated

data from two or more studies to increase sample size

http://80-gateway2.ma.ovid.com.ezproxy.umassmed.edu/ovidweb.cgi?View+Image=00075320-100000000-00870%7CFF1&S=PDPKILJNPAGPKK00D

Guideline

• Ideally based on a systemic review• Focuses on practice implications

of the existing evidence• Informed by expert opinion when

evidence is limited• Usually consensus of multiple

experts• Usually vetted by an organization

The Guide to Community Preventive Services

Evaluating and making recommendations on population-based and public health interventions 

Reviews:

• Evidence on effectiveness

• Applicability of findings to diverse populations

• Intervention's other effects

• Economic impact

• Barriers to implementation of interventions

The Guide to Community Preventive Services

The steps for generating recommendations:

1. Searching for and retrieving evidence on effectiveness

2. Assessing the quality of and summarizing the body of evidence

3. Translating the evidence into recommendations

4. Considering information on evidence other than effectiveness

5. Identifying and summarizing research gaps.

CDC Recommends: The Prevention Guidelines System

• Over 400 documents

• Up-to-date guidance on many public health issues

• Full text or links

• Most published in MMWR

• Sophisticated search engine

• Limited indexing within documents

Comprehensive Knowledge Bases

• Full coverage of important and useful knowledge in one or more domains

• May focus on one or more types of knowledge within a domain (e.g. , pathophysiology, diagnosis, treatment)

• Fills in gaps in evidence with expert opinion

• Key strength: Provides answers to most/all questions asked of it by users

Comprehensive Knowledge Bases

Formats:

• Hardcopies of Textbooks• Electronic Books (Web or CDROM)

– Direct translation of hardcopy– Original electronic texts

• Collections with searching across many items– Databases– Full text journals – Textbooks– Other content

Comprehensive Knowledge Bases

Electronic Books:Direct Translation of

Hardcopy

Comprehensive Knowledge Bases

Collections With Searching Across Many Items

Comprehensive Knowledge Bases

Original Electronic Textbooks

• Original content prepared and organized to facilitate rapid finds of specific information

• May include other databases or texts• Sophisticated indexing displays and search engines• Cross-referenced links within/between chapters • External links to article abstracts of references, etc.• Online, CDROM, PDA • ACP Pier Online, eMedicine, Harrison's Online, Praxis

MD, Sci. Am. Med., UpToDate

UpToDate: Comp. Knowledge Base Example

Topics: Adult Primary Care, Cardiology, Drug

Information Endocrinology, Family Practice, Gastroenterology, Gynecology, Hematology, Hepatology, Infectious Diseases, Nephrology, Obstetrics, Oncology, Pulmonology, Rheumatology, Women's Health

In Development : Allergy/Immunology, Neurology, Pediatrics

UpToDate: Comp. Knowledge Base Example

• Initial cards created by consulting staff of >7000 content experts• In some cases review by practitioners• Extensive editing for consistency by in-house staff of physicians and editors• Monthly review of 300 key journals by in-house staff• Content experts receive any important new studies and must update their card/s• Authors/editors encouraged to use evidence-based methodologies and cite high quality references but no specific evidence criteria

UpToDate

Bulletins, News Reports, Program Reports

• Information often hot off the presses

• Disseminated by Email as individual or collected items

• Often Selected, organized and edited

• May be collected on websites

Bulletins, News Reports, Program Reports: Examples

• TB-related News and Journal Items Weekly Update

• CDC HIV/STD/TB Prevention News Update

• Epi-X reports of outbreaks• Pro-Med Mail reports of outbreaks

Bulletins, News Reports, Program Reports: Strengths and

Weaknesses• Timely information, rapidly

disseminated• Multiple sources• Limited structure, organization, and

indexing• May be provided in large amounts with

limited or no means to locate relevant information (User must browse)

Bulletins, News Reports, Program Reports: Options

• Service to filter, sort, organize and index content in emails and on websites to improve efficiency of access to relevant information