In the outbreak investigation steps, which option indicates the step that assesses the hypothesis using data?

• A. Implement control and prevention efforts
• B. Test hypothesis
• C. Determine if outbreak exists
• D. Communicate findings

Answer: (B)

Assessing a hypothesis with data in an outbreak investigation means using the collected information to see whether the proposed cause actually explains what happened. This is the data-driven evaluation step: you compare exposure and illness among cases and controls (or other relevant groups), calculate measures of association such as relative risk or odds ratio, and determine whether the observed pattern is unlikely to be due to chance. You also consider potential confounding and bias, and you evaluate whether the results are consistent with the hypothesis and with the outbreak’s distribution in time and place. If the data support the proposed link, confidence in the hypothesis increases and you can focus interventions accordingly; if they don’t, you revise the hypothesis and test new ideas. This differs from steps that confirm there is an outbreak, implement control measures, or communicate findings.