The authors regret the inclusion of incorrect values in Table 2 and Sections 3.3, 3.4 and 4.0 of the original article (Hadjistavropoulos et al., 2020). Specifically, the estimated marginal means for.
Table 2.
Means, 95% confidence intervals, and effect sizes (Cohen's d) for primary and secondary outcomes by group with multiple imputations pooling.
| Estimated marginal means |
Percentage changes (%) from pre-treatment |
Within-group effect sizes from pre-treatment |
|||||||
|---|---|---|---|---|---|---|---|---|---|
| Pre-treatment | 8-week follow-up | 12-week follow-up | 24 –week follow-up | 52-week follow-up | To post-treatment | To 52-week follow-up | To post-treatment | To 52-week follow-up | |
| Primary outcomes | |||||||||
| PHQ-9 | |||||||||
| 1W + 1BD S | 12.45 (11.7–13.2) | 6.22 (5.6–6.9) | 6.44 (5.8–7.1) | 6.11 (5.4–6.8) | 6.10 (5.4–6.8) | 50 (45–55) | 51 (45–57) | 1.20 (1.00–1.40) | 1.22 (1.02–1.42) |
| 1W S | 12.19 (11.4–13.0) | 6.21 (5.5–7.0) | 6.13 (5.3–6.9) | 6.08 (5.1–7.0) | 5.48 (4.9–6.1) | 49 (43–55) | 55 (50–60) | 1.09 (0.88–1.29) | 1.27 (1.06–1.48) |
| 1W C | 11.63 (10.9–12.4) | 6.79 (6.1–7.5) | 6.41 (5.6–7.2) | 6.52 (5.7–7.4) | 6.5 (5.8–7.2) | 42 (36–48) | 44 (38–50) | 0.92 (0.72–1.12) | 0.96 (0.76–1.16) |
| GAD-7 | |||||||||
| 1W + 1BD S | 12.1 (11.4–12.8) | 5.9 (5.2–6.6) | 6.05 (5.4–6.7) | 5.08 (4.5–5.7) | 5.46 (4.8–6.1) | 51 (46–57) | 55 (49–60) | 1.31 (1.10–1.51) | 1.39 (1.18–1.60) |
| 1W S | 12.63 (12.0–13.3) | 6.11 (5.2–7.0) | 5.94 (5.2–6.7) | 5.75 (5.1–6.4) | 5.33 (4.7–5.9) | 52 (45–59) | 58 (53–63) | 1.30 (1.08–1.51) | 1.55 (1.33–1.77) |
| 1 W C | 11.75 (11.1–12.4) | 6.28 (5.5–7.0) | 5.85 (5.2–6.5) | 5.48 (4.8–6.2) | 5.64 (5.0–6.3) | 47 (40–53) | 52 (47–57) | 1.12 (0.91–1.32) | 1.27 (1.06–1.47) |
| Secondary outcomes | |||||||||
| K10 | |||||||||
| 1W + 1BD S | 28.82 (27.9–29.8) | 20.93 (19.9–21.9) | 20.91 (20.0–21.8) | 19.28 (18.4–20.2) | 19.86 (18.8–20.9) | 27 (24–31) | 31 (28–35) | 1.06 (0.86–1.26) | 1.24 (1.04–1.44) |
| 1W S | 28.20 (27.9–29.8) | 20.69 (19.6–21.8) | 20.53 (19.2–21.8) | 19.52 (17.9–21.1) | 19.01 (17.8–20.2) | 27 (23−30) | 33 (28–37) | 0.97 (0.77–1.17) | 1.23 (1.02–1.44) |
| 1 W C | 27.85 (26.9–28.8) | 21.49 (20.2–22.8) | 20.94 (19.9–22.0) | 19.18 (18.2–20.1) | 20.18 (19.0–21.3) | 23 (18–27) | 28 (23−32) | 0.86 (0.66–1.05) | 1.02 (0.82–1.22) |
| PDSS-SR | |||||||||
| 1W + 1BD S | 7.68 (6.9–8.4) | 4.63 (4.1–5.2) | 4.25 (3.7–4.8) | 3.28 (2.7–3.8) | 3.62 (3.0–4.3) | 40 (32–47) | 53 (44–61) | 0.60 (0.41–0.79) | 0.81 (0.61–1.00) |
| 1W S | 7.06 (6.3–7.8) | 4.57 (3.9–5.2) | 3.48 (2.8–4.1) | 3.7 (2.9–4.5) | 3.16 (2.5–3.8) | 35 (26–45) | 55 (46–65) | 0.47 (0.27–0.66) | 0.79 (0.59–0.99) |
| 1W C | 7.90 (7.2–8.6) | 5.49 (4.8–6.2) | 4.7 (4.0–5.4) | 3.42 (2.9–3.9) | 3.72 (3.1–4.4) | 30 (21–40) | 53 (45–61) | 0.47 (0.28–0.66) | 0.84 (0.65–1.04) |
| SIAS-6/SPS-6 | |||||||||
| 1W + 1BD S | 14.98 (13.5–16.4) | 11.58 (10.2–12.9) | 11.77 (10.4–13.1) | 10.32 (8.8–11.9) | 11.08 (9.5–12.7) | 23 (14–32) | 26 (15–37) | 0.32 (0.14–0.51) | 0.36 (0.17–0.54) |
| 1W S | 14.69 (13.2–16.1) | 11.29 (9.7–12.9) | 9.43 (8.0–10.8) | 9.50 (8.1–10.9) | 9.87 (8.4–11.3) | 23 (12–34) | 33 (23–43) | 0.32 (0.13–0.52) | 0.46 (0.26–0.65) |
| 1W C | 14.89 (13.4–16.4) | 12.16 (10.8–13.6) | 11.49 (10.2–12.8) | 10.43 (9.0–11.9) | 11.38 (9.9–12.9) | 18 (9–28) | 24 (13–34) | 0.26 (0.07–0.45) | 0.32 (0.13–0.51) |
| PCL-5* | |||||||||
| 1W + 1BD S | 32.98 (30.4–35.5) | – | 24.95 (20.8–29.1) | 22.1 (19.2–25.0) | 22.62 (20.1–25.1) | – | 30 (23–38) | 0.61 (0.42–0.80) | 0.66 (0.47–0.85) |
| 1W S | 35.09 (32.2–38.0) | – | 25.84 (20.0–31.7) | 23.26 (20.5–26.0) | 23.36 (18.6–28.1) | – | 34 (20–47) | 0.71 (0.51–0.91) | 0.68 (0.48–0.88) |
| 1W C | 36.01 (32.7–39.3) | – | 25.41 (21.8–29.0) | 22.56 (20.5–24.6) | 26.08 (23.5–28.7) | – | 27 (20–34) | 0.86 (0.67–1.06) | 0.61 (0.42–0.80) |
| SDS | |||||||||
| 1W + 1BD S | 17.31 (16.3–18.3) | 11.44(10.2–12.7) | 9.87 (8.8–11.0) | 8.07 (7.1–9.0) | 8.47 (7.5–9.5) | 34 (27–41) | 51 (45–57) | 0.73 (0.54–0.92) | 1.14 (0.94–1.34) |
| 1W S | 16.51 (15.4–17.6) | 11.08 (9.8–12.4) | 8.84 (7.8–9.9) | 8.19 (6.9–9.5) | 8.35 (7.2–9.5) | 33 (25–41) | 49 (42–57) | 0.67 (0.47–0.86) | 1.03 (0.83–1.24) |
| 1W C | 16.89 (15.9–17.8) | 11.76 (10.6–12.9) | 10.1 (9.0–11.2) | 8.28 (6.9–9.7) | 9.12 (8.0–10.3) | 30 (23–37) | 46 (39–53) | 0.67 (0.48–0.86) | 0.99 (0.79–1.19) |
Note. 1W = once-weekly; 1BD = one-business-day; S=Specialized Clinic; C = Community Clinics; PHQ-9 = Patient Health Questionnaire-9; GAD-7 = Generalized Anxiety Disorder-7; K10 = Kessler-10; PDSS-SR = Panic Disorder Severity Scale-Self Report; SIAS-6/SPS-6 = Social Interaction Anxiety Scale-6 and Social Phobia Scale-6; PCL-5 = Posttraumatic Stress Disorder Checklist for DSM-5. SDS = Sheehan Disability Scale; 95% confidence intervals are shown in square parentheses for the estimated marginal means, percentage changes, and effect sizes.*PCL-5 was administered at online screening and not pre-treatment and was not administered at 8-week follow-up.
8-, 12-, 24-, and 52-week follow-up were incorrect for the once-weekly specialized clinic (1 W S) on the K10 and PCL-5 due a copy and pasting error.
An additional error was identified for the estimated marginal means, percentage changes from pre-treatment, and within-group effect sizes on the SIAS-6/SPS-6 at 8-, 12-, 24-, and 52-week follow-up. The values in the original article were based on the sum of the 6 items on the SIAS-6 and did not include the 6 items of the SPS-6 in the total score.
A corrected copy of Table 2 and updated description of the results have been included in this corrigendum.
The authors would like to apologise for any inconvenience caused.
3.3. Secondary outcomes
The means, standard deviations, percentage reductions, and Cohen's d effect sizes for the secondary measures for each of the three groups are also presented in Table 2. The GEE analyses revealed statistically significant Time effects for all variables (p < .001), but no significant interactions between Group and Time from pre-treatment to post-treatment and pre-treatment to 52-week follow-up (p range: 0.15–0.84).
3.4. Clinical significance
Percentage change and within group effect sizes from the GEE models are shown in Table 2. For all groups at post-treatment and 52-week follow-up, large within-group effect sizes (Cohen's d: 0.92–1.55) were observed on the PHQ-9, GAD-7, and K10. Medium within-group effect sizes were observed for the PDSS-SR and SDS at post-treatment (Cohen's d: 0.7–0.73), but were large at 52-week follow-up (Cohen's d: 0.79–1.14). On the SIAS-6/SPS-6 effects were small at post-treatment (Cohen's d: 0.29–0.41) and at 52-week follow-up (Cohen's d: 0.32–0.46). For the PCL-5, the effects were moderate from screening to 52-week follow-up (Cohen's d: 0.61–0.68).
4. Discussion
Also consistent with past research on transdiagnostic iCBT, patients in all groups, from pre-treatment to post-treatment showed significant small to moderate improvements in panic (within Cohen's d = 0.47–0.60; avg. % reduction ≥30%–44%), social anxiety (within Cohen's d = 0.26–0.32; avg. % reduction ≥18%–23%), and disability (within Cohen's d = 0.67–0.73; avg. % reduction ≥30%–34%). Of note, from pre-treatment to 52-week follow-up the improvements on panic and disability improved further and were considered large in magnitude (within Cohen's d = 0.79–1.14; avg. % reduction ≥46–55%). Improvements in social anxiety remained small at 52-week follow-up (within Cohen's d = 0.32–0.46; avg. % reduction ≥24–33%).