Which statement best describes how data completeness is assessed?

• A. It is assessed using independent case ascertainment
• B. It is assessed solely by lag-time reports
• C. It is not assessed in quality control
• D. It is assessed only by timeliness measures

Answer: (B)

Data completeness is often monitored by looking at how quickly data arrive after an event, because data that haven’t shown up by a fixed reporting cut-off are effectively incomplete. If there’s a long or highly variable lag between when a case occurs and when its record appears in the dataset, that signals missing data at that point in time, so lag-time measurements serve as a practical indicator of completeness. While independently identifying cases helps ensure broad coverage, it doesn’t by itself quantify how complete the collected data fields are. Quality control does include checks for completeness, but timeliness alone isn’t the same as completeness, and lag-time trends integrate the effect of delayed or missing submissions. So using lag-time reports to gauge whether the dataset is complete at a given point in time is the most informative approach among the options.