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
Emerging Outbreaks
PH
CD
Med
+
+++
+
+++
Published Studies
(Best Evidence)
Policies/Guidelines
+++
++
++
+++
Established Knowledge
+++
++
Emerging Practice/Program
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
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 populationbased 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
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