What is the appropriate ICD-10 (International Classification of Diseases, 10th Revision) code for a patient presenting with confusion and a potential urinary tract infection (UTI)?

ICD-10 Coding for Confusion with Rule Out UTI

For a patient presenting with confusion where you are ruling out UTI, code R41.0 (Disorientation, unspecified) or R41.82 (Altered mental status, unspecified) as the primary diagnosis, NOT a UTI code, until infection is confirmed. 1

Coding Algorithm

Step 1: Code the Presenting Symptom

• Use R41.0 (Disorientation, unspecified) or R41.82 (Altered mental status, unspecified) for confusion/delirium as the primary diagnosis 1
• Do NOT use N39.0 (UTI, site not specified) when UTI is only suspected but not confirmed 1, 2

Step 2: Add Supporting Symptom Codes if Present

• R50.9 (Fever, unspecified) if fever is documented 1
• R82.71 (Bacteriuria) only if urinalysis shows bacteria but infection not yet confirmed 1
• R82.81 (Pyuria) if white blood cells are present in urine 1

Step 3: After Confirmation - Update Coding

• Only code N39.0 (UTI, site not specified) or N30.00 (Acute cystitis without hematuria) once culture confirms infection with ≥100,000 CFU/mL 2
• If pyelonephritis is confirmed, use N10 (Acute pyelonephritis) 1

Critical Coding Pitfalls to Avoid

Do not code a UTI diagnosis based solely on confusion plus positive urinalysis. The IDSA strongly recommends against treating asymptomatic bacteriuria in older patients with delirium, as bacteriuria does not cause confusion and treatment causes harm 1, 3. Coding it as UTI when only ruling it out creates documentation that suggests confirmed infection, which drives inappropriate antibiotic use 4.

Symptom codes alone (like dysuria R30.0) have poor positive predictive value (55.4%) for actual UTI. Using diagnosis codes prematurely without confirmation leads to coding inaccuracy 2. The highest accuracy (96.3% PPV) comes from using both symptom AND confirmed diagnosis codes together 2.

When to Code as Confirmed UTI

Code as UTI only when ALL of the following are present 1:

• Positive urine culture (≥100,000 CFU/mL catheterized or clean-catch specimen)
• Pyuria present (≥10 WBCs/high-power field or positive leukocyte esterase)
• Local genitourinary symptoms (dysuria, urgency, frequency, suprapubic pain) OR systemic signs (fever >100°F, rigors, hemodynamic instability) 1

Special Considerations for Older Adults

In long-term care or elderly patients with confusion 1:

• Confusion alone does NOT indicate UTI even with positive urinalysis
• Asymptomatic bacteriuria is extremely common (up to 50% in elderly women) and should not be coded or treated as UTI 1
• Code the confusion (R41.0 or R41.82) and evaluate for other causes: dehydration, electrolyte abnormalities, medication effects, or other infections 3

Documentation Requirements

For accurate ICD-10 coding, documentation must specify 2, 5:

• Whether UTI is suspected (use symptom codes) vs. confirmed (use diagnosis codes)
• Presence or absence of localizing genitourinary symptoms
• Culture results with organism identification and colony counts
• Whether patient is catheterized (changes to N39.0 for catheter-associated UTI) 1