Renal Tubular Acidosis: Sensitivity and Specificity

Introduction: A cause of non-gap metabolic acidosis. There are multiple types (Type I, II, and IV).

Differential Diagnoses include: Diarrhea

The sensitivity and specificity of findings for Renal Tubular Acidosis are listed below. See the left navigation bar to change the display.

Pre-Test Probability (Prevalence): %.	Post-Test Probability (Predictive Value): %.	Switch to display mode.
Note that calculating probabilities from more than one** finding is inherently inaccurate because findings are not independent. (For example, using two positive findings that share a common pathogenesis is likely to overestimate the true probability.)

Sensitive and Specific Findings
Finding	Result	Sensitivity	Specificity
[ + ] Urine Anion Gap	+ 0 -	100%	100%
UAG > 0, indicating a low [NH4+] in the urine Differential Diagnosis: Diarrhea Study: N Engl J Med. 1988 Mar 10;318(10):594-9. PMID 3344005