Improving participation rates by providing choice of participation mode: two randomized controlled trials

Table 1 Definitions of outcomes

Outcome	Definition
Participation rate	Completed and partially completed SNS interview or questionnaire
Participation rate	Number of participants in TICD-RCT
Conditional participation rate	Completed and partially completed SNS interview or questionnaire
Conditional participation rate	Willing to participate in SNS
Willing to participate	Willing to participate in SNS
Willing to participate	Number of participants in TICD-RCT
Mode preference	Willing to participate in SNS by a particular mode
Mode preference	Received a choice-format invitation and willing to participate in SNS

ISSN: 1471-2288