Table 4.
Adjusted Differences in Mean Daily Step Counts
| Group Comparison | Intervention (wk 1–13) | Follow-up (wk 14–26) | ||
|---|---|---|---|---|
|
|
|
|||
| Difference in Daily Steps (95% CI) | P Value | Difference in Daily Steps (95% CI) | P Value | |
| Main model* | ||||
|
| ||||
| Gain incentive vs. control | 378 (−499 to 1254) | 0.40 | 74 (−801 to 950) | 0.87 |
|
| ||||
| Lottery incentive vs. control | 248 (−644 to 1139) | 0.59 | −55 (−943 to 833) | 0.90 |
|
| ||||
| Loss incentive vs. control | 861 (−20 to 1743) | 0.056 | 496 (−371 to 1363) | 0.26 |
|
| ||||
| Main model adjusted by device† | ||||
| Gain incentive vs. control | 459 (−382 to 1299) | 0.28 | 131 (−702 to 965) | 0.76 |
|
| ||||
| Lottery incentive vs. control | 280 (−575 to 1135) | 0.52 | −33 (−879 to 812) | 0.94 |
|
| ||||
| Loss incentive vs. control | 798 (−48 to 1644) | 0.064 | 439 (−386 to 1265) | 0.30 |
| Main model adjusted by device† and excluding step counts <1000 | ||||
|
| ||||
| Gain incentive vs. control | 406 (−380 to 1193) | 0.31 | 30 (−741 to 802) | 0.94 |
|
| ||||
| Lottery incentive vs. control | 245 (−556 to 1046) | 0.55 | −91 (−873 to 691) | 0.82 |
|
| ||||
| Loss incentive vs. control | 713 (−78 to 1505) | 0.077 | 468 (−293 to 1229) | 0.23 |
*
Adjusted for repeated measures of daily participant step counts and for temporal trends by week using all collected data.
†
Type of smartphone.