How do I find the total number of participants who completed a survey?

The response rate for a survey is calculated by dividing the number of participants who answered the survey (numerator) by the number of participants who potentially completed the survey (denominator). Response rates can be calculated for all surveys in both the Registered and Controlled Tier CDRs with the exception of COVID-19 related surveys within the Registered Tier. This is because date-related COVID-19 related survey data is included as recorded in the Registered Tier while all other dates are shifted according to the Registered Tier date shifting rule (shifted backwards by a random number between 1-365). For COVID survey-related response rate denominator calculations, please see the COVID-19-related Survey Series Details and Resources page.