In CDI audit reporting, confidence intervals are used to express what?

• A. The exact true value of the parameter
• B. The precision of estimates around a parameter with a specified probability
• C. The overall audited sample size
• D. The coding accuracy rate

Answer: (B)

Confidence intervals in CDI audit reporting express how precisely a sample-based estimate reflects the true population parameter, with a specified probability that the interval contains that true value. If we estimate a coding accuracy rate from a sample and build a 95% confidence interval, we’re saying that, in repeated auditing scenarios, about 95% of those intervals would cover the true accuracy rate. The width of the interval reflects sampling variability: larger samples or less variability yield a narrower, more precise interval, while smaller samples or more variability yield a wider interval. The interval does not reveal the exact true value; it expresses our range of plausible values for that true parameter given the data and method. It isn’t about the total audited sample size, nor is it simply the coding accuracy rate itself—it's a probabilistic statement about where the true value lies.