What is the advantage of stratified sampling in CDI audits?

• A. Speeds up audits.
• B. Reduces sample size to zero.
• C. Ensures representation across different patient groups and DRGs, improving generalizability.
• D. Increases complexity.

Answer: (C)

Stratified sampling is valuable because it guarantees representation from different patient groups and DRGs in the CDI audit. By dividing the population into strata that share characteristics (such as DRG categories or patient profiles) and sampling within each group, the audit captures variation across the full spectrum of cases. This leads to more accurate, generalizable findings because results aren’t dominated by the most common or easiest-to-review groups. In practice, it helps reveal DRG-specific or subgroup-specific documentation issues that a simple random sample might miss, improving overall assessment and applicability of the audit outcomes.

The other options don’t capture this benefit: the method doesn’t inherently speed up audits, it doesn’t reduce the sample to zero, and while it can add planning steps, the primary advantage is the representative, generalizable insight it provides.