I thought of something else. My employer has a wellness program where employees get points for 'wellness activities' like screenings and check ups and exercise, and at the end of the year they pay out between $50 - $350 to participants depending on how many points were recorded.

For screenings you have to submit some proof that you went and had a mammogram or colonoscopy or whatever, but the exercise, the self-checks, and seatbelt wearing and not smoking are all self report.