Table 2.
Characteristics of outcomes measured using BMDs according to outcome type (n = 464). Primary outcomes were those that were explicitly reported as such in the published article or in the entry in a public clinical trial registry or, if none was explicitly reported, the outcome(s) stated in the sample size estimation. All other outcomes were considered secondary outcomes
| Primary outcomes (n = 64) | Secondary outcomes (n = 400) | |
|---|---|---|
| Type of sensor used | ||
| Inertial measurement unit sensors | 25 (39) | 108 (27) |
| Electrochemical sensors | 29 (45) | 237 (59) |
| Pressure sensors (including smart cap bottles) | 3 (5) | 35 (9) |
| Optical sensor | 0 (0) | 10 (2) |
| Electrodes | 5 (8) | 9 (2) |
| Temperature sensors | 2 (3) | 1 (0.2) |
| Concept of interest assessed | ||
| Diabetes control | 29 (45) | 237 (59) |
| Assessment of diabetic foot complications | 0 (0) | 2 (0.5) |
| Physical activity | 19 (30) | 68 (17) |
| Blood pressure control | 3 (5) | 29 (7) |
| Adherence to treatment | 6 (9) | 16 (4) |
| Heart rate variability | 5 (8) | 9 (2) |
| Pulmonary capacity | 0 () | 2 (0.5) |
| Sleep disturbance | 2 (3) | 37 (9) |
| Prespecification of the outcome* | 42 (66) | 139 (34) |
*Prespecification was assessed by looking, for each included trial, for the corresponding entry in a public clinical trial registry (e.g., clinicaltrials.gov) by looking for the trial registration number reported in the articles on January 2020 (and June 2020 for articles added during peer-review)