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Therapist-supported, internet-delivered cognitive behavioral therapy (iCBT) is efficacious for generalized anxiety disorder (GAD), but few studies are yet to report its effectiveness in routine care.
In this study, we aim to examine whether a new 12-session iCBT program for GAD is effective in nationwide routine care.
We administered a specialized, clinic-delivered, therapist-supported iCBT for GAD in 1099 physician-referred patients. The program was free of charge for patients, and the completion time was not predetermined. We measured symptoms with web-based questionnaires. The primary measure of anxiety was the GAD 7-item scale (GAD-7); secondary measures were, for pathological worry, the Penn State Worry Questionnaire and, for anxiety and impairment, the Overall Anxiety Severity and Impairment Scale.
Patients completed a mean 7.8 (SD 4.2; 65.1%) of 12 sessions, and 44.1% (485/1099) of patients completed all sessions. The effect size in the whole sample for GAD-7 was large (Cohen
This nationwide, free-of-charge, therapist-supported HUS Helsinki University Hospital–iCBT for GAD was effective in routine care, but further research must establish effectiveness against other treatments and optimize the design of iCBT for GAD for different patient groups and individual patients.
Generalized anxiety disorder (GAD) [
Pharmacotherapy and psychotherapy are considered first-line GAD treatments [
The need to resolve the accessibility and affordability challenges of face-to-face CBT led to the development of internet-delivered CBT (iCBT), with notable work occurring in Sweden, the Netherlands, Denmark, Australia, and Canada, for example [
As demonstrated in recent meta-analyses of randomized controlled trials (RCTs) [
However, RCT efficacy studies, being the gold standard for clinical evidence, have their own shortcomings. Participants are more likely to be highly motivated, have had thorough screening, and have received more intensive treatment than in routine care. Therefore, RCT-validated treatments may or may not yield similar results or level of adherence in routine care depending on whether the criteria are lax [
We identified 5 publications comprising 7 therapist-supported iCBT interventions focusing on GAD in routine care using 3 different programs at 2 clinics. ThisWayUp clinic in Australia performed 6 interventions comprising 2 programs [
The HUS Helsinki University Hospital has developed and is providing nationwide, original Finnish language therapist-supported iCBT programs for several psychiatric conditions (further referred to as HUS-iCBTs), including one for GAD. Intake for the 12-session program requires a physician’s referral, it is free of charge, and therapist support is provided centrally by a specialized clinic. As the combination of setting and design of the HUS-iCBT for GAD differs from those studied earlier, the effectiveness of these programs may differ.
The aim of this study is to examine the effectiveness of HUS-iCBT for GAD in routine care. We hypothesized that the intervention would have a large overall effect size and the patients’ completion rate would be comparable (36%-55%) with the reported routine care studies.
The HUS-iCBTs were delivered centrally by the iCBT clinic at HUS Psychiatry. The interventions were free of charge, diagnosis-specific, and therapist-supported programs. All physicians in Finland can refer their patients to therapy. The referring physicians received support from the instructions on the web. A specially trained mental health professional screened all referrals centrally. We deliberately implemented these inclusion procedures to enable virtually unlimited nationwide access for the clinical population despite the limited number of therapists.
The study was an observational, nationwide, open-label, real-world trial.
Participants were recruited from those entering HUS-iCBT for GAD between February 2016 and December 2018. To be accepted for the treatment, patients had to (1) be diagnosed with GAD (ICD-10 [
The patients provided informed consent after the first log-in. The study protocol was approved by the ethics committee of the HUS and pertinent institutional authorities.
The new iCBT program for GAD was designed by an expert group to be diagnosis-specific because the existing evidence base was clearly the strongest at the time, in 2013. This new program consisted of 12 consecutive sessions and a follow-up session 3 months after treatment completion. The program was theoretically based on several models of GAD and anxiety, including aspects of the cognitive avoidance model [
After approval, the patients received an email and a letter prompting them to sign in and begin treatment. A schedule of 1 session per week was recommended, and a minimum 24-hour waiting period was enforced between sessions to encourage daily life practice. The program sent email prompts for arriving messages and, after 2 weeks of inactivity, log-in reminders. Nevertheless, no maximum completion time was required if the patient remained active in therapy.
Although HUS-iCBT for GAD was therapist-supported, several persuasive elements used in unguided iCBT programs [
Session 1: Introduction to HUS Helsinki University Hospital–internet-delivered cognitive behavioral therapy program, cognitive behavioral therapy model, and generalized anxiety disorder
Session 2: Bodily stress response, worry and relaxation
Session 3: Worry and avoidance, intolerance of uncertainty
Session 4: Experiential Avoidance, Core Beliefs
Session 5: Negative beliefs about worrying, challenging worrying
Session 6: Positive beliefs about worrying, challenging beliefs about worrying
Session 7: Challenging worrying
Session 8: Acceptance of worries, acceptance vs submission
Session 9: Intolerance of uncertainty and reaching for perfection and certainty
Session 10: Problem solving vs worrying, solvable vs unsolvable worries
Session 11: Social skills, needs in relationships, assertiveness
Session 12: Summarizing, warning signs, plan for the future, feedback
Reduction: simple stepped instructions; for example, worry diary or relaxation
Tunneling: logical thematic progression
Self-monitoring: symptom graphs
Simulation: example stories with avatars
Rehearsal: web-based worry diary and relaxation training
Reminders: log-in reminders
Normative influence: normalization of common generalized anxiety disorder features
The therapists in the program were clinical psychologists, psychology students, or nurses with additional therapeutic training, all working at HUS Psychiatry. Each therapist received 1 day of training on internet delivery of CBT, text-based communication, the intervention protocol, and Good Clinical Practice. Therapists received regular group supervision and sought consultation with a senior psychotherapist at any time.
To support patients’ progress, the therapists provided empathic asynchronous feedback with written messages 4 times or more often (if the patient requested) during the therapy. If the patient was inactive for 2 weeks, the therapist pursued contact through an SMS text message or iCBT program. If no reply arrived within a week, further contact was attempted by phone and thereafter by a letter including a 2-week deadline for continuing, after which access to therapy was discontinued.
A web-based report of live data on individual therapists was created during the study to allow for supervision of compliance with the intervention protocol and to prompt support to those failing to ask for support. The report included data on the date of the last log-in and the number of patients not contacted or logged in within the last 2 weeks. The therapist time per patient was not subject to monitoring, but each therapist treated a minimum quota of patients per dedicated working hour. On average, this quota would mean 9 to 11 minutes of working time per patient per week.
Symptoms were measured using web-based questionnaires. The primary measure of anxiety was the GAD-7; secondary measures were, for pathological worry, the Penn State Worry Questionnaire (PSWQ) and, for anxiety and impairment, the Overall Anxiety Severity and Impairment Scale (OASIS).
Patients completed the GAD-7 at the beginning of each of the first 11 sessions and at the end of the final 12th session. The 2 secondary measures were filled at the beginning and end of treatment. Each participant received an invitation for a follow-up measurement 3 months after completing the treatment.
The GAD-7 is a short, 7-item self-report questionnaire developed to measure GAD diagnostic symptom criteria of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition [
The PSWQ is a 16-item questionnaire designed to measure pathological worry, a signature feature of GAD [
The OASIS is a 5-item scale developed as a brief transdiagnostic measure of anxiety severity and impairment [
We measured the number of completed sessions and the time of therapy, defined as the time between the first and last GAD-7 in-therapy measurements. Only patients who completed all 12 sessions were categorized as completers. The program introduced the main theoretical framework in the first 4 sessions, and the later sessions focused mostly on further implementation of basic principles or introduced secondary content. Hence, we subcategorized noncompleters into two groups a priori: early dropouts (those discontinued before the completion of the fourth session) and late dropouts.
We collected patient demographics such as age, registered sex, and municipality class. The municipality class was either urban or nonurban, according to the official Finnish classification [
Our data were a convenience sample of all consented patients who entered treatment after February 2016. Our desired power was 80% and type I error was 0.05 for the main tests and 0.01 for post hoc tests. When comparing 2 independent means, a requirement to detect a small effect size, a minimum of 0.2, would be achieved with a sample of 435 for main tests and 647 for post hoc tests, assuming a 45%/55% completer/noncompleter distribution. For mixed model parameters, we set significance at a conservative
The primary outcome analysis involved a linear mixed random model that allowed growth modeling to account for the changing pace of recovery at different time points during therapy, the use of all available data, and different intercept estimations for each individual. GAD-7 served as the dependent variable, and we modeled a growth curve using linear, quadratic, and cubic terms of the GAD-7 observation time. To control for the effect of
The ITT and noncompleter groups’ effect sizes for GAD-7 were estimated with mixed model–estimated marginal means. This approach generally performs better than a pure last observation carried forward (LOCF) at handling dropout bias, especially in larger samples (n>400 [
We calculated clinical change indexes using the LOCF values. Reliable change was defined as Reliable Change Index (RCI [
We used SPSS Statistics 22 (IBM Corporation) for the analyses [
Of all referrals to the clinic, those rejected during the recruitment period amounted to only 0.6%. Of the 1912 patients who completed the consent form, 1488 (77.82%) provided their consent (
Of the 1099 patients analyzed, 485 (44.13%) fully completed the HUS-iCBT, and a further 363 (33.03%) completed at least the first 4 sessions, meaning that 251 (22.84%) patients dropped out early. Those who completed from 4 to 11 sessions were considered as late dropouts. On average, patients completed 7.8 (SD 4.2; 65.1%) of the 12 sessions. The average time on therapy (time between pretreatment and last measurements) in the whole sample was 128 (SD 97) days, 171 (SD 95) days for completers, 36 (SD 44) days for early dropouts, and 131 (SD 84) days for late dropouts.
At baseline, completers and noncompleters differed in their proportions regarding referral source, municipality class, average age, and OASIS scores (
Patient flowchart. GAD-7: Generalized Anxiety Disorder 7-item scale.
In post hoc analyses, completion was more likely among patients referred from private or occupational care (50.4%) than among those from primary care (39.1%;
In total, 30 therapists treated an average of 37 (SD 38) study patients. Of the 1099 patients, 1097 (99.81%) received at least one message from their therapist, and 796 (72.43%) sent one or more messages to their therapist. Completers sent a message more often (420/485, 86.6% patients) than noncompleters (376/614, 61.2% patients). Therapists sent, on average, 8.4 (SD 4.7) messages and patients (those who did) sent 4.0 (SD 4.2) messages. Of those patients who did send messages, the average number of messages that completers sent (4.9, SD 4.8) was greater than that of noncompleters (3.1, SD 3.1). Therapists sent, on average, more messages to completers (11.6, SD 4.4) than to noncompleters (5.9, SD 3.1).
Baseline characteristics.
Characteristics | Total sample (N=1099) | Completers (n=485) | Noncompleters (n=614) | Completers vs noncompleters | |||||||||
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Test statistic | |||||||||
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.13 | ||||||||||||
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Female | 849 (77.3) | 385 (79.4) | 464 (75.6) |
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Male | 250 (22.7) | 100 (20.6) | 150 (24.4) |
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.002 | ||||||||||||
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Primary care | 601 (54.7) | 235 (48.5) | 366 (59.6) |
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Private or occupational | 339 (30.8) | 171 (35.3) | 168 (27.4) |
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Student health care | 50 (4.5) | 24 (4.9) | 26 (4.2) |
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Psychiatry | 55 (5) | 25 (5.2) | 30 (4.9) |
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Unspecified | 54 (4.9) | 33 (6.8) | 21 (3.4) |
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.004 | ||||||||||||
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Urban | 966 (87.9) | 412 (84.9) | 554 (90.2) |
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Nonurban | 130 (11.8) | 73 (7.2) | 57 (5.7) |
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Age (years), mean (SD) | 33.3 (12.2) | 36.0 (13.1) | 31.1 (12.2) | t935=6.578 | <.001 | ||||||||
GAD-7a, mean (SD) | 13.2 (3.6) | 13.1 (3.6) | 13.3 (3.6) | t1038=0.941 | .35 | ||||||||
PSWQb, mean (SD) | 64.4 (9.8) | 64.7 (9.9) | 64.2 (9.7) | t1031=0.723 | .47 | ||||||||
OASISc, mean (SD) | 12.4 (2.8) | 12.0 (2.8) | 12.7 (2.8) | t1046=4.216 | <.001 |
aGAD-7: Generalized Anxiety Disorder 7-item scale.
bPSWQ: Penn State Worry Questionnaire.
cOASIS: Overall Anxiety Severity and Impairment Scale.
The building of the primary mixed model is described in
The estimated fixed and random effects on GAD-7 are given in
Mixed linear model parameter estimates.
Parameter | Estimate (SE; 95% CI) | Wald Z | ||||||||
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N/Aa |
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Intercept | 12.422 (0.210; 12.01 to 12.83) |
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59.16 (1594.5) | <.001 | |||||
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Observation time (time) | −0.028 (0.004; −0.035 to −0.021) |
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−7.89 (8627.5) | <.001 | |||||
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Time2 | 3.35×10−5 (1.32×10−5; 7.57×10−6 to 5.95×10−5) |
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2.53 (8308.9) | .01 | |||||
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Time3 | −3.39×10−8 (1.18×10−8; −5.70×10−8 to −1.07×10−8) |
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−2.87 (8117.6) | .004 | |||||
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Observation session (session) | −0.523 (0.035; −0.592 to −0.455) |
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−15.00 (8652.5) | <.001 | |||||
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Time × session | 0.002 (0.0003; 0.002 to 0.003) |
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9.11 (8240.2) | <.001 | |||||
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Time × age | −1.32×10−4 (4.10×10−5; 2×10−4 to −5.11×10−5) |
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−3.21 (8669.3) | .001 | |||||
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N/A |
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Private or occupational | N/A |
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N/A | N/A | ||||
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Psychiatry | 2.059 (0.530; 1.018 to 3.099) |
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3.88 (1289.4) | <.001 | ||||
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Other | 1.409 (0.533; 0.363 to 2.454) |
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2.64 (1272.5) | .008 | ||||
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Student health care | 0.500 (0.559; −0.597 to 1.598) |
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0.89 (1336.0) | .37 | ||||
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Primary care | 0.919 (0.249; 0.430 to 1.408) |
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3.68 (1303.0) | <.001 | ||||
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N/A |
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Private or occupational | N/A |
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N/A | N/A | ||||
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Psychiatry | 0.001 (0.002; −0.004 to 0.006) |
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0.34 (8163.2) | .73 | ||||
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Other | 0.004 (0.002; −0.001 to 0.009) |
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1.58 (8140.2) | .11 | ||||
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Student health care | 0.010 (0.003; 0.004 to 0.015) |
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3.46 (8193.8) | .001 | ||||
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Primary care | 0.004 (0.001; 0.002 to 0.006) |
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3.51 (8219.9) | <.001 | ||||
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N/A |
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Completers, as reference | N/A |
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N/A | N/A | ||||
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Late dropouts | 0.005 (0.001; 0.002 to 0.008) |
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3.44 (8677.2) | .001 | ||||
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Early dropouts | 0.003 0.004; −0.005 to 0.012) |
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0.72 (8525.7) | .47 | ||||
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Residual | 9.40 (0.15; 9.11 to 9.70) | 61.76 | N/A | <.001 | |||||
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Patient intercept | 10.56 (0.52; 9.59 to 11.63) | 20.34 | N/A | <.001 |
aN/A: not applicable.
Estimated mean marginal values based on linear mixed model versus observed values. Curves depict an average patient trajectory. GAD-7: Generalized Anxiety Disorder 7-item scale.
Treatment effect sizes are given in
At the 3-month follow-up, 111 completers were reached, which accounted for 10.1% of the whole sample and 22.9% of the completers. The observed change in the GAD-7 score was −6.8. For secondary measures, changes were −11.3 in PSWQ and −3.9 in OASIS.
Treatment effects based on estimated marginal means and observed values.
Treatment effect | Baseline, mean (SD) | Post, mean (SD) | Pre–post, change | Pre–post, correlation | Effect size, Cohen |
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Completersb | 13.1 (3.6) | 7.0 (4.7) | −6.1 | 0.267 | 1.39 (1.25-1.53) | ||||||
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Early dropouts | 12.9 (3.6) | 11.5 (4.5) | −1.3 | 0.377c | 0.34 (0.16-0.51) | |||||
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Late dropouts | 12.9 (3.6) | 9.4 (5.1) | −3.5 | 0.351c | 0.85 (0.70-1.00) | |||||
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ITTd analysis | 12.9 (3.6) | 8.7 (4.7) | −4.1 | 0.308c | 0.97 (0.88-1.06) | |||||
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Completersb | 64.7 (9.9) | 53.7 (13.6) | −11.0 | 0.526 | 1.14 (1.00-1.27) | ||||||
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Completersb | 12.0 (2.8) | 8.4 (3.9) | −3.6 | 0.452 | 1.23 (1.09-1.37) |
aGAD-7: Generalized Anxiety Disorder 7-item scale.
bFewer patients completed the PSWQ and OASIS after the treatment (n=479).
cOnly these correlations were calculated from before the treatment and the last observed values for those with ≥2 observations.
dITT: intention to treat.
ePSWQ: Penn State Worry Questionnaire. For PSWQ and Overall Anxiety Severity and Impairment Scale, only baseline scores were available for noncompleters; hence, only complete effect sizes were observed.
fOASIS: Overall Anxiety Severity and Impairment Scale.
Clinical change indexes based on the GAD-7 scores are provided in
Indexes for PSWQ and OASIS were reported only for completers because noncompleters had only one observation. Reliable change on PSWQ was a change of >12 points and 40.9% (196/479) reliably improved and 1% (5/479) reliably deteriorated. On OASIS reliable change was a change of >3 points and 48.6% (233/479) reliably improved and 1.5% (7/479) reliably deteriorated.
Clinical indexes at the final on-therapy observation.
Clinical index | ITTa, n (%) | Completers, n (%) | Late dropoutsb (sessions ≥4), n (%) | Early dropoutsb (sessions <4), n (%) | |||||
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1099 (100) | 485 (100) | 363 (100) | 251 (100) | |||||
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Reliable improvementd | 532 (48.4) | 306 (63.1) | 170 (46.8) | 56 (22.3) | ||||
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Reliable deterioratione | 41 (3.73) | 12 (2.5) | 19 (5.2) | 10 (4) | ||||
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894 (100) | 385 (100) | 295 (100) | 214 (100) | |||||
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Reliable improvementd | 479 (53.6) | 268 (69.6) | 155 (52.5) | 56 (26.2) | ||||
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Recoveryf | 486 (54.4) | 280 (72.7) | 149 (50.5) | 57 (26.6) | ||||
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Reliable recoveryg | 421 (47.1) | 244 (63.4) | 129 (43.7) | 48 (22.4) | ||||
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Reliable deterioratione | 27 (3) | 9 (2.3) | 11 (3.7) | 7 (3.3) |
aITT: intention to treat.
bOn the basis of the last observed values.
cGAD-7: Generalized Anxiety Disorder 7-item scale.
dGAD-7 score drop of ≥5.
eGAD-7 score increase of ≥5.
fGAD-7 changed to <10 at after the treatment.
gBoth reliably improved and recovered.
This nationwide, free-of-charge, therapist-supported HUS-iCBT for GAD in routine care, with no predetermined maximum completion time, comprised 1099 patients referred by their physicians. To the best of our knowledge, this study has the largest reported real-world sample involving iCBT for GAD. The patients reported substantial improvement in ITT analyses amounting to effect sizes of Cohen
The change in GAD-7 score was comparable with that achieved in 3 of the 4 Australian ThisWayUp trials (Cohen
Interestingly, from both practical and theoretical viewpoints, the longer it took for patients to complete a given number of sessions, the less they improved. It is plausible that the effects of therapy become diluted if the patient’s commitment to therapy weakens. Therefore, methods of increasing engagement in therapy seem one of the most promising ways to increase the effectiveness of iCBT for GAD.
The change in the PSWQ for completers (Cohen
The OASIS-measured anxiety-related functional impairment demonstrated a large improvement in the completers (Cohen
Our completers improved faster than late dropouts, unlike those in 2 earlier studies, which showed no or negligible differences. However, significant improvement was also observed in our noncompleters, which could imply heterogeneity in this population. Feedback offered by the patients who withdrew from the Online Therapy Unit intervention also suggests that several patients may have discontinued treatment as their symptoms improved [
Although not unequivocally proven, clinician-referred patients in iCBT tend to exhibit lower effect sizes than community-recruited or self-referred ones [
In the ITT analysis using LOCF, of HUS-iCBT patients with a baseline GAD-7 score ≥10, 54.4% (486/894) of patients achieved recovery. This recovery rate is comparable with that reported earlier in face-to-face CBT for GAD (51.4% [
Moreover, the criteria for reliable change in our study and previous studies differed, which prevented direct comparison. In one meta-analysis of RCTs of iCBT, reliable deterioration occurred in 3.1% (95% CI 1.5%-5.9%) of patients in trials for anxiety disorders [
The full completion rate in our study (485/1099, 44.13%) was similar to the rates in previous routine care trials (36%-55%) but lower than that in a meta-analysis of routine care iCBT for depression and anxiety (61%) [
The proportion of completed sessions in HUS-iCBT (65%) was marginally lower than that in the earlier trials (67%-77% in ThisWayUp’s and 72% in Online Therapy Unit’s trials) but somewhat higher than that in the previously mentioned meta-analysis (57% [
Compared with our noncompletion rate (614/1099, 55.86%), face-to-face individual psychotherapy for GAD has had a low dropout rate of 17% in a meta-analysis of RCT trials [
In our study, completers sent and received more messages than did noncompleters. Our data do not allow exploration of causality, but this finding may be intuitively explained by the completer’s longer time on therapy. In the Online Therapy Unit’s trial [
Older patients improved more and faster than younger patients. At first glance, this seems counterintuitive, as one could presume that young, digital native patients could feel more comfortable in the digital realm than the older ones. Nevertheless, 1 of the 3 ThisWayUp’s trials also found that older age predicted larger improvement [
Moreover, younger patients were less likely to complete the program than their older counterparts. This relationship has been a common finding in iCBT for GAD in routine care [
Gender had no significant influence on adherence in our study, similar to the findings of Australian studies. Systematic reviews of RCTs on face-to-face psychotherapy for GAD or CBT for anxiety disorders have also found no significant gender-adherence relationship [
The full completion rate was higher among patients referred from private or occupational health (171/339, 50.4%) than among those referred from primary care (235/601, 39.1%). Their symptoms improved faster than those referred from students or primary health care. These effects could be due to patient-group differences: patients referred from occupational health are, by definition, employed and presumably have a higher average level of functioning, higher socioeconomic status, and a lower likelihood of serious comorbidities. Moreover, in our recent study, physicians in occupational health displayed more interest in sending patients to iCBT than their primary care counterparts [
Patients from nonurban municipalities were more likely to complete the therapy (73/130, 56.2%) than those from urban municipalities (412/966, 42.7%). This relationship is somewhat opposed to the findings in the 2012 report by Mewton et al [
The results of this and earlier studies in routine care are, in general, comparable despite considerable differences in setting, design, and support.
To the best of our knowledge, HUS-iCBT and the Online Therapy Unit’s programs had no predetermined maximum therapy completion time, whereas ThisWayUp applied a typical fixed maximum time restriction (90 days). The time from the first to last observation on HUS-iCBT (128 days) and from the first to last log-in at the Online Therapy Unit (135 days) were comparable and longer than the typical 90 days in other trials. Although the lack of a predetermined maximum time span may support adherence during changing life situations, it could also disengage some patients and dilute therapy effects, thereby leading to an increased dropout rate. As confounding design and sample features exist, such as different numbers of sessions and differences in sample average age, the optimal time span remains unknown.
In the Australian studies, patients were referred to iCBT by their own independent clinicians, each of whom was required to register as a provider, to receive training, and to use an assessment toolkit. The Online Therapy Unit required a centralized diagnostic interview. Our HUS-iCBT only screened referrals from physicians (but not from other clinicians) with no obligatory registration or any specific assessment schema. The practice at HUS-iCBT was chosen as the middle ground to ensure proper diagnostics while maintaining a high intake flow. To maintain a low threshold, the inclusion criteria in HUS-iCBT were purposely loose, with only 0.6% (51/8394) of all physician referrals rejected during the recruitment period, and this may have contributed to a possible patient–therapy mismatch.
In HUS-iCBT, the support was provided centrally by specially trained and supervised mental health professionals, as recommended by authors from 5 universities who argue that iCBT requires specialized expertise and processes [
HUS-iCBT was free of charge for the patients, as was the treatment at the Online Therapy Unit. Patients in ThisWayUp paid approximately Aus $49 (US $37) for the treatment, which may have ensured motivation and therefore improved adherence [
The main strengths of this study are its nationwide scope, the largest sample thus far reported, and its routine care setting. One could argue that reliance on self-report measures can inflate treatment effects, but 2 recent meta-analyses suggest that combining indexes based on self-reporting can be even conservatively biased [
Other routine care studies did not use PSWQ or OASIS. Their addition in our study shows that iCBT for GAD can ease pathological worry and anxiety-related impairments in routine care. Although they both offer important information, they may not be as sensitive to change as the GAD-7.
Concomitant treatments, including psychopharmaceuticals, are often offered to patients in routine care. Information on these treatments is not reliable. This limits our understanding of the possible interactions between different treatments.
Not all comorbidities may have appeared in patient documents in referrals, and depressive symptoms were not measured. This issue is particularly relevant for GAD, as its annual comorbidity with major depression is around 41% [
We could not, retrospectively, reliably identify the therapist behind each message sent to the patient. We know that due to vacation periods, illness, or leaving HUS, not all messages sent to a patient may have come from the same therapist. This prevented us from analyzing the effect of the individual therapist, their profession, or other relevant training.
Only 23% (111/485) of completers were reached for the 3-month follow-up. Such high attrition limits our conclusions regarding long-term effectiveness. However, we did not include follow-up data in the linear mixed model analyses, and these limited data do not compromise the main results.
Thus far, therapist-supported iCBT for GAD has not been compared with other active treatment forms or no treatment in routine care, making comparisons with active controls, coupled with health economic analyses, essential. Not all patients benefit from iCBT for GAD. Both transdiagnostic programs and tailoring content to individual needs have displayed promising results [
Adherence to iCBT for GAD seems to be lower in primary care than in RCT trials. Evidence is emerging for adapted therapist support for patients at risk for dropout [
iCBT programs often retain a considerable number of text-based answers and messages. Text mining approaches could offer an exciting avenue for exploring qualitative phenomena. Such analyses could be beneficial for both theoretical research and the practical application of iCBT.
The optimal time schedules for or the number of sessions in iCBT for GAD remain unclear. Further comparison studies should seek to establish more suitable, effective, and economic combinations. Age and other demographic variables may also influence the outcomes of iCBT for GAD. To provide equally effective care for everyone, future studies should investigate how to overcome hurdles presented by demographic variables.
PSWQ and OASIS were not used in other routine care studies. They represent both diagnosis-specific and transdiagnostic processes related to GAD and anxiety in general. OASIS, a short self-rating scale, opens up a venue for further comparative research between iCBT for various psychiatric disorders. As PSWQ measures pathological worry, a theoretically important GAD feature, an in-depth psychometric examination of PSWQ may reveal important information on moderators and mediators of effectiveness.
Since the collection of our data, HUS-iCBT for GAD has adopted a novel technical platform, a predetermined maximum completion time (20 weeks), pretreatment phone calls, and weekly therapist support. These changes may have practical implications that will enable further studies.
This nationwide, free-of-charge, therapist-supported HUS-iCBT for GAD with no predetermined maximum completion time was effective at improving symptoms and reducing worry and functional impairment in routine care. Overall, this therapy appears to be safer than no treatment and is at least as effective as other therapist-supported iCBTs for GAD. The observed gains at the 3-month follow-up should be confirmed in future studies. Future research needs to establish comparative effectiveness against other treatments and to optimize the benefit of iCBT for GAD in a variety of patient groups and individual patients.
Description of primary mixed model building and statistics.
cognitive behavioral therapy
generalized anxiety disorder
Generalized Anxiety Disorder 7-item scale
internet-delivered cognitive behavioral therapy
intention to treat
last observation carried forward
Overall Anxiety Severity and Impairment Scale
Penn State Worry Questionnaire
Reliable Change Index
randomized controlled trial
This work was supported by the Government of Finland and the Hospital Region of Helsinki and Uusimaa.
None declared.