When using statistical data in infection prevention, which statement is true?

• A. Statistical data can prove associations with high confidence.
• B. Statistical data cannot prove an association, only suggest that it exists.
• C. Statistical data can establish causation.
• D. Statistical data are always inconclusive.

Answer: (C)

Statistics reveal relationships between factors, but they do not prove that one causes the other. In infection prevention, you might observe that sites with higher hand hygiene compliance have fewer infections, yet this association could be influenced by other variables like patient mix, staffing, or reporting practices. The data give you the strength and precision of the relationship and indicate that an association exists, but they don’t provide definitive proof of causation. To argue causation, you need additional support: temporality (the exposure comes before the outcome), control for confounding, a consistent pattern across studies, a plausible dose–response, and ideally evidence from randomized or rigorously designed studies. So, statistical data are best described as providing evidence of an association and its strength, not establishing causation on their own.