PICO
-systematic approach in framing questions Patients Intervention Comparison Outcomes
Medline
- general medical database produced by the national library of medicine
- accessed via PubMed and Ovid
- includes more than 10 million citations from 4000 medical journals
- the database starts from 1966
Embase
- consists of 3 linked databases
- Excerpta Medica and two special databases for pharmacology and psychiatry
CINAHL
- Cumulative Index to Nursing and Allied Health database
- specialises in literature relating to nursing and allied health professions
PsycLIT
- database produced by the American Psychological Association
- covers psychological journals and books from 1887 to the present
Cochrane Library
-consists of a collection of databases including Database of Systematic Reviews: Database of Abstracts of Reviews of Effectiveness; the Cochrane controlled Trials Register and teh Cochrane Methodology Register
SIGLE
system of information on Grey literature in Europe
-includes many difficult to obtain dissertations and conference abstracts
Impact factor
-the impact factor for a journal is calculated based on a three year period
-the average number of times published papers are cited up to two years after publication
A= number of times articles published in 2008-9 were cited during indexed journals during 2010
B= the number of articles, reviews, proceedings or notes published in 2008-2009
-impact factor for 2010= A/B
Publication bias
- results are more apt to be published if they are significant or shown in a large sample
- many negative studies and small studies remain unpublished
Time lag bias
-significant results are published sooner than non-significant results
Language bias
-significant results are submitted to English-Language journals, non-significant results to non-English journals
Database bias
-studies with significant results are more likely to be published in a journal that is indexed in a database
Citation bias
-likelihood of article being cited depends on the significance of results and size of the trial
Duplicate publication bias
-results of the same study appear in more than one publication
Outcome reporting bias
-selective reporting of some study results and not reporting other analyses
MeSH
- Medical Subject Headings
- controlled vocabulary of biomedical terms that is used to describe the subject of each journal article in MEDLINE
- MeSH contains more than 23,000 terms
Internal validity
- the extent that a study can be used to drawn conclusions about cause and effect
- high levels of bias,, confounding factors and measurement errors threaten internal validity
- random assignment of intervention improves internal validity
External validity
- refers to the extent that a study can be generalised to other places, subjects and times
- real world setting
- random sampling improves external validity
CONSORT
- Consolidated Standards of Reporting Trials
- looks at enrollment, allocation, follow up and analysis
- CONSORT statement is an evidence-based, minimum set of recommendations for reporting RCTs
- offers a standard way for authors to prepare reports of trial findings, facilitating their complete and transparent reporting and aiding their critical appraisal and interpretation
QUOROM statement
- The quality of reporting of meta-analyses (QUOROM) statement
- evidence based, minimum set of recommendations for improving the quality of reporting of meta-analyses of clinical randomised controlled trials (RCTs)
PRISMA
- preferred reporting items for systematic reviews and meta-analyses
- evidence-based minimum set of items for reporting in systematic reviews and meta-analysis
- replaced QUOROM in 2009
- aim of PRISMA is to help authors improve reporting of systematic reviews and meta-analyses
STROBE
- an international, collaborative initiative of epidemiologists, methodologists etc involved in the conduct and dissemination of observational studies with the common aim of STrengthening the Reporting of OBservational studies in Epidemiology
- 22 items that are considered essential for good reporting of observational studies
ASSERT statement
- the articulation of A Standard for the Scientific and Ethical Review of Trials
- proposes a structured approach whereby research ethics committees review proposals for and monitor the conduct of randomised controlled clinical trials
- ASSERT checklist comprises of items that need to be addressed by investigators applying for approval to conduct a clinical trial
MOOSE statement
-The Meta-analysis of Observational Studies in Epidemiology statement
