Longitudinal Study Attrition & Retention Diagnostic

Welcome to this brief survey about your experience participating in this longitudinal study. This survey asks about your participation patterns, any challenges you have encountered, and your preferences for reminders and incentives. Your responses will help us improve the study experience for all participants. • Your participation is entirely voluntary and you may stop at any time. • There are no right or wrong answers—we are interested in your honest opinions. • All responses are confidential and will be reported only in aggregate. • Estimated completion time: 7–9 minutes. By continuing, you indicate that you have read the above and consent to participate.

Thinking about the last 12 months, which best describes your participation in this study?

• Completed every scheduled time point
• Missed one time point
• Missed more than one time point
• Joined recently (completed only the first time point)
• I don't recall

What were the reasons you missed one or more time points, or seriously considered skipping? Please select all that apply.

• Scheduling conflict or time constraints
• Forgot or missed the deadline
• Survey felt too long
• Time points were too frequent
• Incentives felt too low
• Technical issues (link, device, or login)
• Instructions were unclear
• Did not see reminders in time
• Questions felt too personal or sensitive
• Health or family issues
• In-person visit was difficult to attend
• Lost interest or topic no longer felt relevant
• Concern about data privacy
• Other reason
• Prefer not to say

Please rank the following factors by how much they motivate you to complete each time point, from most motivating (top) to least motivating (bottom).

1. Contributing to important research
2. Receiving the incentive/payment
3. Getting personalized feedback or results
4. Feeling a sense of commitment to the study team
5. The survey process being quick and easy
6. Receiving timely and helpful reminders

How burdensome has the length of each survey session been over the last 12 months?

How would you prefer to receive reminders for upcoming time points? Select all that apply.

• Email
• SMS / text message
• Phone call
• Push notification in an app
• Calendar invite (Google / Outlook)
• Messaging app (e.g., WhatsApp)
• None — I do not want reminders

If you could suggest one change to make it easier to complete every time point, what would it be? Feel free to also share any other thoughts about your experience in this study.

What is your age group?

• 18–24
• 25–34
• 35–44
• 45–54
• 55–64
• 65 or older
• Prefer not to say

Thank you for completing this survey. Your responses are confidential and will be used to improve the study experience for all participants. Your input is greatly valued.

Of the reasons you selected, which single factor had the greatest impact on your most recent missed or nearly-missed time point?

• Scheduling conflict or time constraints
• Forgot or missed the deadline
• Survey felt too long
• Time points were too frequent
• Incentives felt too low
• Technical issues (link, device, or login)
• Instructions were unclear
• Did not see reminders in time
• Questions felt too personal or sensitive
• Health or family issues
• In-person visit was difficult to attend
• Lost interest or topic no longer felt relevant
• Concern about data privacy
• Other reason
• Not sure / Don't remember

How burdensome has the frequency of time points been over the last 12 months?

How far in advance of a time point would you like to receive the first reminder?

• Same day
• 1 day before
• 3 days before
• 1 week before
• 2 weeks before

Which gender do you identify with?

• Woman
• Man
• Non-binary
• Self-describe
• Prefer not to say

In the last 12 months, did you ever seriously consider skipping a time point or withdrawing from the study entirely?

• Yes
• No
• Prefer not to say

How burdensome has scheduling around your other commitments been over the last 12 months?

Which types of incentives would you most value? Select up to 3.

• Cash transfer
• Electronic gift card
• Prepaid debit card
• Charity donation in my name
• Entry into a prize drawing
• Course credit
• Personalized feedback or report
• Other (please specify)

What is the highest level of education you have completed?

• High school or less
• Some college / Associate degree
• Bachelor's degree
• Postgraduate (Master's / PhD / Professional)
• Other
• Prefer not to say

How burdensome have technical aspects of participation (e.g., logging in, loading surveys, device compatibility) been over the last 12 months?

Overall, how fair do you feel the study's current incentives are relative to the time and effort required?

Which best describes your current employment status?

• Employed full-time
• Employed part-time
• Self-employed
• Student
• Unpaid caregiver
• Retired
• Unemployed and seeking work
• Unemployed and not seeking work
• Unable to work
• Prefer not to say

Compared to the time and effort each time point requires, how adequate is the current incentive amount?

In which region do you currently live?

• Africa
• Asia
• Europe
• North America
• Oceania
• South America
• Prefer not to say