How do you calculate 1000 catheter days for assessing Catheter-Associated Urinary Tract Infections (CAUTIs) risk?

How to Calculate 1000 Catheter Days

To calculate 1000 catheter days, sum the total number of days all urinary catheters were in place during a defined period, then divide the number of catheter-associated infections by this total and multiply by 1000. 1

Calculation Method

The formula for calculating catheter-associated infection rates per 1000 catheter days is:

(Number of infections / Total catheter days) × 1000

Step-by-Step Process:

1. Count total catheter days:

   • Track each patient with a catheter
   • Count each day a catheter is in place as one catheter day
   • Sum all catheter days across all patients during your measurement period

2. Count infections:

   • Identify all catheter-associated infections during the same period
   • Use standardized definitions (e.g., CDC/NHSN criteria)

3. Calculate the rate:

   • Divide the number of infections by total catheter days
   • Multiply by 1000 to express as infections per 1000 catheter days

Example Calculation

If you had:

• 5 catheter-associated UTIs in a month
• 50 patients with catheters
• Total of 450 catheter days (sum of all days each catheter was in place)

The calculation would be:

(5 infections ÷ 450 catheter days) × 1000 = 11.1 infections per 1000 catheter days

Importance of This Metric

This standardized metric allows for:

• Meaningful comparison between different units, hospitals, or time periods 1
• Risk adjustment based on catheter utilization
• Benchmarking against national data
• Evaluation of infection prevention interventions

The CDC and Joint Commission on Accreditation of Healthcare Organizations (JCAHO) recommend expressing catheter-associated infection rates per 1000 catheter days rather than as a percentage of catheters, as it accounts for the duration of catheter use, which is the primary risk factor for infection 1.

Common Pitfalls to Avoid

• Inconsistent counting: Ensure all catheter days are accurately tracked
• Validation errors: The International Society for Infectious Diseases recommends validating electronically collected catheter days against manual methods, with an acceptable margin of error not exceeding ±5% 1
• Failure to stratify: Consider stratifying rates by unit type, as infection rates vary significantly by hospital service 2
• Inconsistent definitions: Use standardized infection definitions to ensure valid comparisons

By accurately calculating and tracking catheter days, healthcare facilities can better monitor infection rates, implement targeted interventions, and ultimately reduce the morbidity and mortality associated with catheter-related infections.