Effectiveness of the online tailored advice (TrailS6 )
| Outcomes | Estimates at each time point | Within-group effect | Between-group effect | ||||||||||
| First measurement | 2 months | 6 months | After 2 months | After 6 months | After 2 months | After 6 months | |||||||
| Intervention mean (95% BCI) | Control mean (95% BCI) | Intervention mean (95% BCI) | Control mean (95% BCI) | Intervention mean (95% BCI) | Control mean (95% BCI) | Intervention ES (95% BCI) | Control ES (95% BCI) | Intervention ES (95% BCI) | Control ES (95% BCI) | ES (95% BCI) | ES (95% BCI) | BF | |
| Determinants of performing the intervention* | |||||||||||||
| Intention | 1.29 (1.14 to 1.45) | 1.20 (1.05 to 1.35) | 1.19 (1.05 to 1.33) | 1.22 (1.08 to 1.35) | 1.09 (0.90 to 1.26) | 1.23 (1.05 to 1.41) | −0.10 (−0.20 to −0.01)† | 0.02 (−0.08 to 0.11) | −0.21 (−0.40 to −0.02)† | 0.03 (−0.16 to 0.22) | −0.12 (−0.26 to 0.01) | −0.24 (−0.52 to 0.03) | 0.0 |
| Attitude | 1.28 (1.18 to 1.39) | 1.17 (1.06 to 1.27) | 1.26 (1.17 to 1.36) | 1.23 (1.13 to 1.32) | 1.25 (1.13 to 1.37) | 1.29 (1.17 to 1.41) | −0.02 (−0.07 to 0.04) | 0.06 (0.00 to 0.12)† | −0.03 (−0.15 to 0.09) | 0.12 (0.01 to 0.24)† | −0.08 (−0.16 to 0.01) | −0.16 (−0.32 to 0.01) | 0.0 |
| Subjective norm | 0.52 (0.33 to 0.72) | 0.45 (0.25 to 0.65) | 0.58 (0.41 to 0.76) | 0.57 (0.40 to 0.74) | 0.65 (0.42 to 0.88) | 0.69 (0.46 to 0.92) | 0.06 (−0.06 to 0.18) | 0.12 (0.00 to 0.24) | 0.12 (−0.12 to 0.37) | 0.24 (−0.01 to 0.48) | −0.06 (−0.23 to 0.11) | −0.12 (−0.47 to 0.23) | 0.3 |
| Perceived behavioural control | 1.07 (0.94 to 1.20) | 0.95 (0.82 to 1.08) | 1.02 (0.90 to 1.14) | 0.95 (0.83 to 1.07) | 0.96 (0.81 to 1.11) | 0.94 (0.80 to 1.10) | −0.05 (−0.13 to 0.02) | 0.00 (−0.08 to 0.08) | −0.11 (−0.26 to 0.04) | −0.01 (−0.15 to 0.15) | −0.05 (−0.16 to 0.06) | −0.10 (−0.31 to 0.11) | 0.2 |
| Preventive behaviours included in the intervention (%)‡ | |||||||||||||
| Warming up | 50.6 (41.6 to 59.4) | 52.5 (43.6 to 61.3) | 49.8 (41.8 to 57.5) | 48.2 (40.5 to 56.0) | 49.1 (38.6 to 59.2) | 43.9 (33.6 to 54.1) | −0.7 (−6.5 to 4.9) | −4.3 (−9.9 to 1.3) | −1.5 (−13.0 to 9.7) | −8.6 (−19.9 to 2.7) | 3.6 (−4.3 to 11.6) | 7.2 (−8.6 to 23.1) | 4.2 |
| Cooling down | 44.3 (35.6 to 53.0) | 38.7 (30.2 to 47.3) | 42.8 (35.3 to 50.2) | 36.2 (28.7 to 43.6) | 41.3 (31.3 to 51.6) | 33.7 (23.8 to 44.0) | −1.5 (−7.0 to 4.4) | −2.5 (−8.2 to 3.3) | −3.0 (−14.1 to 8.9) | −5.0 (−16.4 to 6.5) | 1.0 (−7.2 to 8.9) | 2.0 (−14.5 to 17.8) | 1.5 |
| Trail running shoes | 56.0 (47.3 to 64.9) | 58.4 (49.8 to 67.1) | 50.5 (42.9 to 58.1) | 50.0 (42.6 to 57.6) | 44.9 (34.7 to 55.2) | 41.6 (31.4 to 51.9) | −5.5 (−11.3 to 0.2) | −8.4 (−14.2 to −2.7)† | −11.0 (−22.6 to 0.5) | −16.8 (−28.4 to −5.3)† | 2.9 (−5.2 to 11.0) | 5.8 (−10.4 to 22.0) | 3.1 |
| Strength training | 48.0 (39.4 to 57.1) | 43.7 (35.1 to 52.5) | 43.1 (35.2 to 50.8) | 45.2 (37.5 to 53.0) | 38.2 (27.9 to 48.4) | 46.7 (36.4 to 56.8) | −4.9 (−10.5 to 0.7) | 1.5 (−4.2 to 6.9) | −9.8 (−20.9 to 1.4) | 3.0 (−8.5 to 13.8) | −6.4 (−14.3 to 1.5) | −12.8 (−28.6 to 3.1) | 0.1 |
| Core training | 57.7 (48.7 to 66.5) | 53.1 (44.2 to 61.9) | 55.9 (48.1 to 63.7) | 52.7 (44.7 to 60.3) | 54.1 (43.8 to 64.2) | 52.3 (41.9 to 62.4) | −1.8 (−7.3 to 3.7) | −0.4 (−5.9 to 5.1) | −3.5 (−14.6 to 7.5) | −0.8 (−11.8 to 10.2) | −1.4 (−9.2 to 6.4) | −2.7 (−18.4 to 12.7) | 0.6 |
| Neuromuscular training | 30.2 (22.4 to 38.0) | 27.0 (19.3 to 34.7) | 26.2 (19.3 to 33.1) | 24.8 (17.9 to 31.7) | 22.2 (13.0 to 31.1) | 22.7 (13.5 to 31.5) | −4.0 (−8.9 to 0.8) | −2.2 (−6.9 to 2.8) | −8.0 (−17.8 to 1.6) | −4.3 (−13.9 to 5.5) | −1.9 (−8.9 to 4.8) | −3.7 (−17.8 to 9.6) | 0.4 |
| Flexibility training | 41.4 (32.7 to 49.8) | 36.2 (27.6 to 44.5) | 36.3 (28.8 to 43.9) | 35.6 (28.0 to 43.0) | 31.3 (21.4 to 41.2) | 35.0 (25.1 to 44.9) | −5.0 (−10.3 to 0.5) | −0.6 (−6.1 to 4.7) | −10.1 (−20.6 to 1.0) | −1.2 (−12.2 to 9.4) | −4.4 (−12.2 to 3.2) | −8.8 (−24.4 to 6.4) | 0.1 |
| Preventive behaviours not included in the intervention (%)‡ | |||||||||||||
| Compression clothing | 7.2 (3.1 to 11.4) | 3.9 (0.0 to 8.1)§ | 7.1 (3.5 to 10.6) | 5.2 (1.6 to 8.7) | 7.0 (2.1 to 11.9) | 6.6 (1.8 to 11.6) | −0.1 (−3.0 to 2.8) | 1.4 (−1.6 to 4.2) | −0.2 (−6.0 to 5.6) | 2.8 (−3.1 to 8.5) | −1.5 (−5.7 to 2.5) | −2.9 (−11.4 to 5.1) | 0.3 |
| Compression stocking | 30.4 (22.6 to 38.1) | 22.6 (15.0 to 30.3) | 26.9 (19.9 to 33.8) | 21.9 (15.2 to 29.0) | 23.4 (14.7 to 32.2) | 21.3 (12.6 to 30.2) | −3.5 (−8.0 to 0.9) | −0.7 (−5.1 to 3.8) | −7.0 (−15.9 to 1.9) | −1.3 (−10.1 to 7.6) | −2.8 (−9.2 to 3.5) | −5.7 (−18.4 to 6.9) | 0.2 |
| Insoles | 16.2 (10.0 to 22.6) | 15.6 (9.4 to 21.9) | 13.8 (8.1 to 19.4) | 13.8 (8.3 to 19.4) | 11.3 (4.0 to 18.5) | 12.1 (4.8 to 19.1) | −2.5 (−6.2 to 1.3) | −1.8 (−5.5 to 2.0) | −4.9 (−12.5 to 2.7) | −3.5 (−11.1 to 4.0) | −0.7 (−6.1 to 4.5) | −1.4 (−12.2 to 9.0) | 0.7 |
| Stretching before | 30.6 (22.4 to 38.7) | 29.6 (21.6 to 37.8) | 29.0 (21.6 to 36.2) | 29.6 (22.4 to 36.9) | 27.3 (18.1 to 36.7) | 29.7 (20.4 to 39.0) | −1.7 (−6.5 to 3.1) | 0.0 (−4.8 to 4.7) | −3.3 (−13.0 to 6.2) | 0.1 (−9.7 to 9.5) | −1.7 (−8.4 to 5.2) | −3.4 (−16.8 to 10.4) | 0.4 |
| Stretching after | 45.3 (36.4 to 54.2) | 46.4 (37.6 to 55.2) | 43.0 (35.1 to 50.9) | 46.6 (38.8 to 54.5) | 40.7 (30.6 to 50.9) | 46.7 (36.6 to 56.7) | −2.3 (−7.6 to 3.1) | 0.2 (−5.1 to 5.5) | −4.6 (−15.2 to 6.1) | 0.3 (−10.2 to 10.9) | −2.5 (−9.9 to 5.2) | −5.0 (−19.8 to 10.4) | 0.3 |
| Supervised training | 29.1 (21.8 to 36.7) | 19.9 (12.6 to 27.3) | 26.0 (19.4 to 32.7) | 19.0 (12.4 to 25.6) | 22.9 (14.5 to 31.6) | 18.1 (9.7 to 26.8) | −3.1 (−7.5 to 1.5) | −0.9 (−5.5 to 3.4) | −6.1 (−14.9 to 3.1) | −1.8 (−11.0 to 6.8) | −2.2 (−8.5 to 4.1) | −4.3 (−17.1 to 8.3) | 0.3 |
| Taping | 6.3 (2.4 to 10.4) | 5.1 (1.2 to 9.0) | 7.4 (4.1 to 10.8) | 3.4 (0.1 to 6.8) | 8.4 (3.8 to 13.1) | 1.8 (0.0 to 6.5)§ | 1.0 (−1.8 to 3.8) | −1.7 (−4.4 to 1.2) | 2.1 (−3.5 to 7.7) | −3.3 (−8.8 to 2.4) | 2.7 (−1.2 to 6.7) | 5.4 (−2.4 to 13.4) | 10.1 |
| Running-related injury (%)‡ | 46.3 (39.4 to 53.5) | 37.7 (30.6 to 44.6) | 42.3 (35.9 to 48.7) | 36.9 (30.6 to 43.4) | 30.3 (22.9 to 37.8) | 34.8 (27.4 to 42.2) | −4.0 (−5.8 to −2.1)† | −0.7 (−2.5 to 1.1) | −16.0 (−23.0 to −8.6)† | −2.8 (−9.9 to 4.2) | −3.3 (−5.8 to −0.8)¶ | −13.1 (−23.3 to −3.1)¶ | 194.3 |
Results regarding the effects between groups are in favour of the intervention group.
*Effect sizes are expressed as mean differences obtained by Bayesian linear mixed models.
†95% BCI not containing the null effect (ie, zero) for within-group and between-group effects.
‡Effect sizes are expressed as absolute risk difference obtained by Bayesian linear probability mixed models.
§The lower bound of the 95% BCI of these estimates was negative. As probability (non-comparative) cannot be negative, the lower bound of the 95% BCI of these estimates was constrained to zero.
¶Significant results (ie, 95% BCI not containing the null effect and BF>3 for within-group and between-group effects).
BCI, Bayesian highest posterior density credible interval; BF, Bayes factor (calculated for the regression coefficient of the interaction term composed by group and time); ES, effect size.