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
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
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