Disclaimer
is Guideline attempts to define principles of practice that should produce high-quality patient
care. It is applicable to specialists, primary care, and providers at all levels. is Guideline
should not be considered exclusive of other methods of care reasonably directed at obtaining the
same results. e ultimate judgment concerning the propriety of any course of conduct must be
made by the clinician aer consideration of each individual patient situation.
Neither IGC, the medical associations, nor the authors endorse any product or service associated
with the distributor of this clinical reference tool.
Abbreviations
BLT, bow and lean test; BPPV, benign paroxysmal positional vertigo; CRP, canalith
repositioning procedure; TIA, transient ischemic attack
Source
Bhattacharyya N, Gubbels SP, Schwartz SR, et al; Clinical Practice Guideline: Benign
Paroxysmal Positional Vertigo (Update). Otolaryngol Head Neck Surg. 2017; 156(3_
suppl):s1-s47.
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AAOHNSBPPV1723
Aggregate Grades of Evidence by Question Type
Grade Treatment Diagnosis Prognosis
A
Systematic review
a
of
randomized trials
Systematic review
a
of
cross-sectional studies
with consistently
applied reference
standard and blinding
Systematic review
a
of inception cohort
studies
b
B Randomized trials, or
observational studies
with dramatic effects
or highly consistent
evidence
Cross-sectional studies
with consistently
applied reference
standard and blinding
Inception cohort
studies
b
C Non-randomized or
historically controlled
studies, including
case-control and
observational studies
Non-consecutive
studies, case-control
studies, or studies with
poor, non-independent,
or inconsistently
applied reference
standards
Cohort study, control
arm of a randomized
trial, case series, or
case-control studies;
poor quality prognostic
cohort study
D Case reports, mechanism-based reasoning, or reasoning from first principles
X Exceptional situations where validating studies cannot be performed and there
is a clear preponderance of benefit over harm
a
A systematic review may be downgraded to level B because of study limitations, heterogeneity, or
imprecision
b
A group of individuals identified for subsequent study at an early, uniform point in the course of
the specified health condition, or before the condition develops
