Table 2. Results of Linear Quantile Mixed Models for the Primary Outcome and a Selection of Secondary Outcomes.
| Outcome | Participants with available data, No. | ERP (n = 111)a | Comparator (n = 110)a | Intention-to-treat linear quantile mixed model | ||||
|---|---|---|---|---|---|---|---|---|
| Median (IQR) | Mean (SD) | Median (IQR) | Mean (SD) | Coefficient (95% CI)b | P value | Effect size (95% CI)b,c | ||
| YGTSS-TTSS | ||||||||
| Baseline | 221 | 23 (18 to 26) | 22.25 (5.60) | 24 (19 to 27) | 23.01 (5.92) | NA | NA | NA |
| Posttreatment | 213 | 19 (13 to 23) | 18.53 (5.94) | 20 (15 to 24) | 19.27 (7.20) | NA | NA | NA |
| 3-mo follow-upd | 216 | 17 (11 to 21) | 16.17 (6.82) | 19 (12 to 23) | 17.72 (7.11) | −0.53 (−1.28 to 0.22) | .17 | 0.11 (−0.09 to 0.30) |
| YGTSS Impairment | ||||||||
| Baseline | 221 | 20 (10 to 20) | 18.38 (7.08) | 20 (10 to 20) | 18.73 (7.79) | NA | NA | NA |
| Posttreatment | 213 | 10 (0 to 20) | 10.65 (8.68) | 10 (0 to 20) | 11.52 (9.59) | NA | NA | NA |
| 3-mo follow-upd | 216 | 10 (0 to 10) | 7.68 (8.82) | 10 (0 to 10) | 8.70 (8.10) | −0.26 (−1.70 to 1.18) | .72 | 0.05 (−0.34 to 0.44) |
| CGI-S | ||||||||
| Baseline | 221 | 4 (4 to 5) | 4.08 (0.74) | 4 (4 to 5) | 4.19 (0.72) | NA | NA | NA |
| Posttreatment | 213 | 4 (3 to 4) | 3.50 (0.86) | 4 (3 to 4) | 3.69 (0.91) | NA | NA | NA |
| 3-mo follow-upd | 216 | 3 (3 to 4) | 3.24 (0.92) | 4 (3 to 4) | 3.49 (0.90) | −0.36 (−0.67 to −0.04) | .03e | 0.71 (0.05 to 1.37) |
| PTQ | ||||||||
| Baseline | 221 | 32 (19 to 44) | 34.33 (19.06) | 34 (21 to 51) | 38.04 (23.27) | NA | NA | NA |
| Midtreatmentf | 210 | 22 (13 to 39) | 25.73 (16.14) | 26 (15 to 41) | 29.83 (18.82) | NA | NA | NA |
| Posttreatment | 214 | 17 (10 to 30) | 21.08 (15.75) | 19.5 (11 to 36.5) | 25.05 (18.18) | NA | NA | NA |
| 3-mo follow-upd | 211 | 14 (6 to 25) | 19.84 (17.92) | 19 (7.5 to 37.5) | 23.51 (18.14) | 0.13 (−1.43 to 1.68) | .87 | −0.01 (−0.22 to 0.19) |
| C&A-GTS-QOL | ||||||||
| Baseline | 221 | 27 (17 to 39) | 29.11 (15.06) | 27.5 (18 to 43) | 30.54 (16.54) | NA | NA | NA |
| Posttreatment | 212 | 15 (8 to 28.5) | 19.68 (15.48) | 20.5 (12 to 31) | 22.86 (15.71) | NA | NA | NA |
| 3-mo follow-upd | 208 | 16 (8 to 28) | 19.76 (16.26) | 17 (9 to 27) | 20.05 (15.72) | 0.46 (−1.63 to 2.55) | .67 | −0.04 (−0.24 to 0.16) |
Abbreviations: C&A-GTS-QOL, Child and Adolescent Gilles de la Tourette Syndrome–Quality of life scale; CGI-S, Clinical Global Impression–Severity scale; ERP, therapist-supported internet-delivered exposure with response prevention for children and adolescents with Tourette syndrome or chronic tic disorder; PTQ, Parent Tic Questionnaire; YGTSS, Yale Global Tic Severity Scale; YGTSS-TTSS, Yale Global Tic Severity Scale–Total Tic Severity Score.
Observed values calculated from completer data.
Estimates (negative or positive) compare with the comparator as the reference point.
Bootstrapped effect sizes, interpreted as between-group differences in median relative the interquartile range, are derived from the linear quantile mixed models.
Primary end point.
Significant at an α = .05.
Five weeks into treatment.