than 130 journals are reviewed to identify articles that meet our
criteria for scientific merit, as set out below:
Basic criteria for original or review articles:
- in English.
- about adult
- about topics
that are important to the clinical practice of general practice/family
practice, general internal medicine and its subspecialties other
than descriptive studies of prevalence.
of each article is consistent with the study question.
Studies of prevention or treatment must meet these additional criteria:
Studies of diagnosis must meet these additional criteria:
- random allocation
of participants to comparison groups.
(endpoint assessment) of at least 80% of those entering the investigation.
measure of known or probable clinical importance.
of a spectrum of participants, some but not all of whom have the
disorder or derangement of interest.
diagnostic ("gold") standard (e.g., laboratory test
not requiring interpretation) OR current clinical standard for
diagnosis (e.g., a venogram for deep venous thrombosis), preferably
with documentation of reproducible criteria for subjectively interpreted
diagnostic standard (i.e., report of statistically significant
measure of agreement beyond chance among observers).
- each participant
must receive both the new test and some form of the diagnostic
interpretation of diagnostic standard without knowledge of test
of test without knowledge of diagnostic standard result.
Studies of prognosis must meet these additional criteria:
cohort of individuals, all initially free of the outcome of interest.
of at least 80% of patients until the occurrence of a major study
endpoint or to the end of the study.
Studies of etiology must meet these additional criteria:
of the relation between exposures and putative clinical outcomes.
data collection with clearly identified comparison groups for
those at risk for the outcome of interest (in descending order
of preference from randomized controlled trial, quasi-randomized
controlled trial, nonrandomized controlled trial, cohort studies
with case-by-case matching or statistical adjustment to create
comparable groups, to nested case-control studies.
of observers of outcomes to exposures (criterion assumed to be
met if outcome is objective, i.e., all-cause mortality, objective
Studies of quality improvement or continuing education must meet
these additional criteria:
- random allocation
of participants or units to comparison groups.
of at least 80% of participants.
measure of known or probable clinical or educational importance.
the economics of health care programs or interventions must
meet these additional criteria:
- the economic
question addressed must be based on comparison of alternatives
in real patients.
diagnostic or therapeutic services or quality improvement activities
must be compared on the basis of both the outcomes produced (effectiveness)
and resources consumed (costs).
of effectiveness must be from a study (or studies) of real (not
hypothetical) patients, which meets the above-noted criteria for
diagnosis, treatment, quality improvement, or a systematic review
article that also meets criteria.
should be presented in terms of the incremental or additional
costs and outcomes of one intervention over another.
- where uncertainty
exists in the estimates or imprecision in the measurement, a sensitivity
analysis should be done.
Studies of clinical prediction guides must meet these additional criteria:
- the guide
must be generated in one or more sets of real (not hypothetical)
patients (training set).
- the guide
must be validated in another set of real (not hypothetical) patients
(test set) and must deal with treatment, diagnosis, prognosis,
Studies of differential diagnosis must meet these additional criteria:
- a cohort
of patients who present with a similar, initially undiagnosed
but reproducibly defined clinical problem.
setting, including the referral filter, is explicitly described.
ascertainment of diagnosis for 80% of patients using a reproducible
diagnostic workup strategy for all patients and follow-up until
patients are diagnosed or follow-up of 1 month for acute disorders
or 1 year for chronic or relapsing disorders.
review articles must meet these additional criteria:
- an identifiable
description of the methods indicating the sources and methods
for searching for articles.
of the clinical topic and the inclusion and exclusion criteria
for selecting articles for detailed review.
- at least
one article in the review must meet the above noted criteria for
treatment, diagnosis, prognosis, clinical prediction, etiology,
quality improvement, economics of health care, or differential
are subject to modification if, for example, it is found feasible
to apply higher standards that increase the validity and applicability
of studies for clinical practice. The objective of the criteria
screen is to include only the very best literature, consistent with
a reasonable number of articles "making it through the filter."