TABLE 6.
Associations between funding sources and study characteristics for intervention studies
| Study funding source1 | ||||||
|---|---|---|---|---|---|---|
| Mixed (n = 74) | Government only (n = 65) | Industry only (n = 47) | Nonprofit only (n = 52) | Not reported (n = 60) | P 2 | |
| Median sample size,3n | 18 | 18 | 33 | 17.5 | 17 | 0.0001* |
| Duration, n (%) | 0.14 | |||||
| <1 d | 24 (32) | 25 (38) | 21 (45) | 24 (46) | 31 (52) | |
| 1–14 d | 23 (31) | 20 (31) | 9 (19) | 12 (23) | 5 (8) | |
| 15–31 d | 12 (16) | 7 (11) | 2 (4) | 9 (17) | 10 (17) | |
| >1 to 6 mo | 13 (18) | 12 (18) | 13 (28) | 7 (13) | 12 (20) | |
| >6 to 1 y | 1 (1) | 1 (2) | 1 (2) | 0 (0) | 0 (0) | |
| >1 to 2 y | 0 (0) | 0 (0) | 1 (2) | 0 (0) | 2 (3) | |
| >2 y | 1 (1) | 0 (0) | 0 (0) | 0 (0) | 0 (0) | |
| Study design, n (%) | 0.06 | |||||
| Randomized (parallel) | 16 (22) | 13 (20) | 15 (32) | 18 (35) | 10 (17) | |
| Randomized (crossover) | 29 (39) | 39 (60) | 25 (53) | 22 (42) | 34 (57) | |
| Nonrandomized | 14 (19) | 5 (8) | 2 (4) | 3 (6) | 8 (13) | |
| Single-arm | 11 (15) | 4 (6) | 3 (6) | 6 (12) | 8 (13) | |
| Other | 4 (5) | 4 (6) | 2 (4) | 3 (6) | 0 (0) | |
| Included power calculation, n (%) | 0.40 | |||||
| Yes | 2 (15) | 11 (42) | 8 (36) | 8 (38) | 3 (21) | |
| No | 11 (85) | 15 (58) | 14 (64) | 13 (62) | 11 (79) | |
| Study is randomized, n (%) | 0.02* | |||||
| Yes | 45 (61) | 52 (80) | 40 (85) | 40 (77) | 44 (73) | |
| No | 29 (39) | 13 (20) | 7 (15) | 12 (23) | 16 (27) | |
| Outcome categories, n (%) | ||||||
| Diabetes risks | 53 (72) | 40 (62) | 27 (57) | 35 (67) | 46 (77) | 0.20 |
| Cardiovascular disease risks | 45 (61) | 33 (51) | 20 (43) | 26 (50) | 23 (38) | 0.10 |
| Body weight | 23 (31) | 14 (22) | 12 (26) | 15 (29) | 10 (17) | 0.34 |
| Body composition | 14 (19) | 8 (12) | 5 (11) | 7 (13) | 3 (5) | 0.20 |
| Appetite | 19 (26) | 13 (20) | 11 (23) | 8 (15) | 8 (13) | 0.38 |
| Dietary intake | 19 (26) | 7 (11) | 7 (15) | 8 (15) | 4 (7) | 0.03* |
| Liver health | 8 (11) | 3 (5) | 4 (9) | 7 (13) | 2 (3) | 0.23 |
| Other | 44 (59) | 41 (63) | 22 (47) | 26 (50) | 23 (38) | 0.04* |
1
Mixed indicates studies funded by >1 funding source category; Government only indicates studies exclusively funded by a government source.
2
P values were derived by chi-square test, with the exception of Sample size (Kruskal-Wallis test). *Significant, α = 0.05.
3
The median sample size in each category.