Diagnosis of Gout: A Systematic Review in Support of an American College of Physicians Clinical Practice Guideline.
BACKGROUND
Alternative strategies exist for diagnosing gout that do not rely solely on the documentation of monosodium urate (MSU) crystals.


OBJECTIVE
To summarize evidence regarding the accuracy of clinical tests and classification algorithms compared with that of a reference standard of MSU crystals in joint aspirate for diagnosing gout.


METHODS
Several electronic databases from inception to 29 February 2016.


METHODS
21 prospective cohort, cross-sectional, and case-control studies including participants with joint inflammation and no previous definitive gout diagnosis who had MSU analysis of joint aspirate.


METHODS
Data extraction and risk-of-bias assessment by 2 reviewers independently; overall strength of evidence (SOE) judgment by group.


RESULTS
Recently developed algorithms including clinical, laboratory, and imaging criteria demonstrated good sensitivity (up to 88%) and fair to good specificity (up to 96%) for diagnosing gout (moderate SOE). Three studies of dual-energy computed tomography (DECT) showed sensitivities of 85% to 100% and specificities of 83% to 92% for diagnosing gout (low SOE). Six studies of ultrasonography showed sensitivities of 37% to 100% and specificities of 68% to 97%, depending on the ultrasonography signs assessed (pooled sensitivity and specificity for the double contour sign: 74% [95% CI, 52% to 88%] and 88% [CI, 68% to 96%], respectively [low SOE]).


CONCLUSIONS
Important study heterogeneity and selection bias; scant evidence in primary and urgent care settings and in patients with conditions that may be confused with or occur with gout.


CONCLUSIONS
Multidimensional algorithms, which must be validated in primary and urgent care settings, may help clinicians make a provisional diagnosis of gout. Although DECT and ultrasonography also show promise for gout diagnosis, accessibility to these methods may be limited.


BACKGROUND
Agency for Healthcare Research and Quality. (Protocol registration: https://effectivehealthcare.ahrq.gov/ehc/products/564/1937/gout-protocol-140716.pdf).
From RAND Corporation, Santa Monica, and David Geffen School of Medicine at the University of California and Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California.
Sydne J
SJ
Newberry
From RAND Corporation, Santa Monica, and David Geffen School of Medicine at the University of California and Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California.
John D
JD
FitzGerald
From RAND Corporation, Santa Monica, and David Geffen School of Medicine at the University of California and Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California.
Aneesa
A
Motala
From RAND Corporation, Santa Monica, and David Geffen School of Medicine at the University of California and Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California.
Marika
M
Booth
From RAND Corporation, Santa Monica, and David Geffen School of Medicine at the University of California and Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California.
Margaret A
MA
Maglione
From RAND Corporation, Santa Monica, and David Geffen School of Medicine at the University of California and Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California.
Dan
D
Han
From RAND Corporation, Santa Monica, and David Geffen School of Medicine at the University of California and Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California.
Abdul
A
Tariq
From RAND Corporation, Santa Monica, and David Geffen School of Medicine at the University of California and Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California.
Claire E
CE
O'Hanlon
From RAND Corporation, Santa Monica, and David Geffen School of Medicine at the University of California and Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California.
Roberta
R
Shanman
From RAND Corporation, Santa Monica, and David Geffen School of Medicine at the University of California and Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California.
Whitney
W
Dudley
From RAND Corporation, Santa Monica, and David Geffen School of Medicine at the University of California and Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California.
Paul G
PG
Shekelle
D000465:Algorithms; D006073:Gout / Q000145:classification / Q000175:diagnosis* / Q000000981:diagnostic imaging; D006801:Humans; D017410:Practice Guidelines as Topic; D012015:Reference Standards; D012680:Sensitivity and Specificity; D013582:Synovial Fluid / Q000737:chemistry; D014527:Uric Acid / Q000032:analysis
D014527:Uric Acid