هزینه اثربخشی و بالینی رفتاردرمانی شناختی با هدایت درمانگر با ارائه اینترنتی برای افراد پیرتر با علائم اضطراب: یک کارآزمایی تصادفی

There is preliminary support for internet-delivered cognitive behaviour therapy (iCBT) as a way of improving access to treatment among older adults with anxiety. The aim of this randomized controlled trial (RCT) was to examine the efficacy, long-term outcomes, and cost-effectiveness of an iCBT program for adults over 60 years of age with anxiety. Successful applicants were randomly allocated to either the treatment group (n = 35) or the waitlist control group (n = 37). The online treatment course was delivered over 8 weeks and provided with brief weekly contact with a clinical psychologist via telephone or secure email. Eighty-four percent of participants completed the iCBT course within the 8 weeks and 90% provided data at posttreatment. Significantly lower scores on measures of anxiety (Cohen’s d = 1.43; 95% CI: 0.89 – 1.93) and depression (Cohen’s d = 1.79; 95% CI: 1.21 – 2.32) were found among the treatment group compared to the control group at posttreatment. These lower scores were maintained at 3-month and 12-month follow-up and the treatment group rated the iCBT treatment as acceptable. The treatment group had slightly higher costs ($92.2; 95% CI: $38.7 to $149.2) and Quality-Adjusted Life-Years (QALYs = 0.010; 95% CI: 0.003 to 0.018) than the control group at posttreatment and the intervention was found to have a greater than 95% probability of being cost-effective. The results support iCBT as an efficacious and cost-effective treatment option for older adults with symptoms of anxiety.

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Results Preliminary Tests No differences were found between the treatment and control groups on the demographic variables shown in Table 1. The number of treatment group participants meeting diagnostic criteria at pretreatment and at 3-month follow-up is shown in Table 2. No differences were found between the treatment and control groups in the proportions meeting diagnostic criteria (ps > .05). No differences were found between participants who did not complete posttreatment questionnaires and those who completed posttreatment questionnaires on age, hours of internet use, medication use, confidence with the internet and number of diagnoses or pretreatment symptoms of anxiety or depression (ps > .05). Table 2. Frequency Data of Participants’ Diagnoses At time of application 3-Month Follow-up Treatment Group Control Group Total Treatment Group n % n % n % n % MINI-Diagnosis MDE 14 42 18 48 32 45 5 15 PAN/AG 13 39 10 27 23 32 4 12 SP 10 30 10 27 20 28 3 9 OCD 3 9 1 2 4 5 1 3 PTSD 2 6 1 2 3 4 2 6 GAD 16 48 23 62 39 55 2 6 Number of diagnoses 0 8 24 5 13 13 18 23 69 1 5 15 15 40 20 28 5 15 2 9 27 3 8 12 17 3 9 3 10 30 14 37 24 34 2 6 4 0 0 0 0.0 0 0 0 0 5 1 3 0 0.0 1 1 0 0 Note. Baseline observations were carried forward for missing data. Abbreviations: MDE, Major Depressive Episode; PAN/AG, panic disorder/Agoraphobia; SP, social phobia; OCD, Obsessive Compulsive Disorder; PTSD, Post Traumatic Stress Disorder; GAD, Generalised Anxiety Disorder. Table options Symptom Outcomes for Overall Sample Means and standard deviations for the overall sample on the GAD-7 and the PHQ-9 are shown in Table 3. The mixed-models analyses examining GAD-7 scores revealed a significant main effect for Time (F3,139 = 40.91, p < .001) and a significant Time × Group interaction (F1,190 = 44.88, p < .001). For the PHQ-9, analyses revealed a significant main effect for Time (F3,149 = 32.20, p < .001) and a significant Time × Group interaction (F1,190 = 45.21, p < .001). Pairwise comparisons revealed the treatment group had significantly lower GAD-7 and PHQ-9 scores than the waitlist control group (p < .001) at posttreatment. The GAD-7 and the PHQ-9 scores of the treatment group at posttreatment, 3-month, and 12-month follow-up were all significantly lower than their pretreatment scores (ps < .001). There were no significant changes in the treatment group from posttreatment to 3-month follow-up or from the 3-month to the 12-month follow-up (ps > .05), indicating that initial symptom reductions from pretreatment to posttreatment were maintained at follow-up. Table 3. Means, Standard Deviations and Effect Sizes (Cohen’s d) for the Observed and Estimated Marginal Means n Observed Means (Completer Data) Estimated Means (Mixed Models Data) Effect sizes (Based On Observed Means) Pre Post 3-Month Follow-up 12-Month Follow-up Pre Post 3-Month Follow-up 12-Month Follow-up Within Group pre to post Between Group post treatment Within Group pre to 3-month Within Group pre to 12-month OVERALL SAMPLE GAD-7 Treatment 33 11.67 (5.34) 3.90 (2.94) 4.57 (3.79) 4.03 (3.27) 11.41 (3.10) 3.56 (3.26) 4.22 (3.25) 3.74 (3.29) 1.80 (1.21 – 2.35) 1.43 (0.89 –1.93) 1.53 (0.97 – 2.06) 1.73 (1.14 – 2.27) Control 37 10.35 (4.41) 9.75 (4.91) – – 10.94 (3.11) 10.22 (3.35) – – 0.13 (-0.33 – 0.58) – – PHQ-9 Treatment 33 10.76 (4.79) 3.63 (2.68) 3.93 (3.81) 3.93 (3.44) 10.74 (2.96) 3.63 (3.11) 3.93 (3.11) 3.90 (3.15) 1.84 (1.24 – 2.39) 1.79 (1.21 – 2.32) 1.31 (0.77 – 1.83) 1.43 (0.88 – 1.96) Control 37 10.78 (4.37) 10.47 (4.62) – – 10.75 (2.96) 10.56 (3.18) – – 0.07 (-0.39 – 0.52) – – CLINICAL SAMPLE GAD-7 (GAD-7 ≥ 8) Treatment 23 14.48 (3.57) 4.90 (2.80) 5.10 (3.76) 4.85 (3.32) 14.03 (3.10) 4.46 (3.24) 4.65 (3.24) 4.40 (3.29) 2.99 (2.10 – 3.77) 1.62 (0.95 – 2.23) 2.56 (1.74 – 3.29) 2.79 (1.94 – 3.55) Control 27 12.41 (3.12) 11.21 (4.64) – – 13.16 (3.14) 11.93 (.3.32) – – 0.30 (-0.24 – 0.84) – – PHQ-9 (GAD-7 ≥ 8) Treatment 23 12.83 (3.78) 4.14 (2.55) 4.43 (3.73) 4.05 (3.17) 12.64 (4.09) 4.02 (2.93) 4.31 (2.93) 3.84 (2.99) 2.70 (1.86 – 3.44) 2.18 (1.45 – 2.84) 2.24 (1.47 – 2.93) 2.52 (1.71 – 3.24) Control 27 12.37 (3.54) 12.00 (4.30) – – 12.46 (2.80) 12.43 (2.97) – – 0.09 (-0.44 – 0.63) – – Note. GAD-7; Generalised Anxiety Disorder 7-item. PHQ-9; Patient Health Questionnaire 9-item. Table options Symptom Outcomes for Clinical Sample Means and standard deviations for the clinical sample (GAD-7 total scores ≥ 8) for the GAD-7 and the PHQ-9 are shown in Table 3. The mixed-models analyses revealed a significant main effect for Time (F3,97 = 47.81, p < .001) and a significant Time × Group interaction (F1,135 = 44.31, p < .001) on the GAD-7. Similarly, a significant main effect for Time (F3, 108 = 38.04, p < .001) and a significant Time × Group interaction (F1, 135 = 55.47, p < .001) were found on the PHQ-9. Pairwise comparisons revealed the treatment group had significantly lower GAD-7 and PHQ-9 scores than the waitlist control group (p < .001) at posttreatment. The GAD-7 and PHQ-9 scores of the treatment group at posttreatment, 3-month, and 12-month follow-up were all significantly lower than their pretreatment scores (ps < .001). There were no significant changes in the treatment group from posttreatment to 3-month follow-up or from the 3-month to the 12-month follow-up (ps > .05), indicating that initial symptom reductions from pretreatment to posttreatment were maintained at follow-up. Clinical Contact The mean total therapist time per participant in the treatment group was 57.58 minutes (SD = 31.30; range = 17–144 mins), which included sending and reading secure email messages and telephoning participants. An additional 40 minutes of therapist time was required per participant for administrative purposes and the conduct of diagnostic interviews. Clinical Significance The proportions of participants reporting reliable improvement and reliable recovery are shown in Table 4. Chi-square analyses indicated greater proportions of reliable improvement and reliable recovery on the GAD-7 and the PHQ-9 in the treatment group compared to the waitlist control group (p < .001). At 3-month and 12-month follow-up, over 75% of the treatment group reported reliable improvement on the GAD-7 and the PHQ-9. Table 4. Proportions Reporting Reliable Improvement and Reliable Recovery CLINICAL SAMPLE n Post-Treatment 3- Month Follow-Up 12- Month Follow-Up Reliable Improvement χ2 Reliable Recovery χ2 Reliable Improvement Reliable Recovery Reliable Improvement Reliable Recovery GAD-7 (GAD-7 ≥ 8) Treatment 23 19 / 23 (82.6%) χ2 = 20.43, p < .001 18 / 23 (78%) χ2 = 17.86, p < .001 18 / 23 (78.3%) 18 / 23 (78%) 19 / 23 (82.6%) 16 / 23 (69%) Control 27 5 / 27 (18.5%) 5 / 27 (18%) – – – – PHQ-9 (PHQ-9 ≥ 10) Treatment 19 15 /19 (78.9%) χ2 = 18.45, p < .001 14 / 19 (73%) χ2 = 15.88, p < .001 15 / 19 (78.9%) 15 / 19 (78.9%) 14 / 19 (73.6%) 13 / 19 (68.4%) Control 23 3 / 23 (13%) 3 / 23 (13%) – – – – Note. Baseline observations were carried forward for missing data. A person was deemed to have made a reliable improvement if they scored above the total cut-off at pre-treatment and their symptoms improved by a reliable amount. A person was deemed to have reliably recovered if they scored above the clinical cut-off at pre-treatment, made a Reliable Improvement, and scored below the clinical cut-off at the post-treatment or follow-up time point of interest. GAD-7; Generalised Anxiety Disorder 7-item. PHQ-9; Patient Health Questionnaire 9-item. Table options Treatment Satisfaction Of participants who completed the post-treatment questionnaires (n = 28), 67% (n = 19) reported that they were very satisfied with the course, 21% (n = 6) reported that they were mostly satisfied, 3% (n = 1) gave a rating of neutral and 7% (n = 2) reported that they were somewhat dissatisfied. No participants reported that they were very dissatisfied with the course. Of respondents, 96% (n = 27) would recommend the course to a friend and 96% (n = 27) reported that the course was worth their time. Economic Analysis In the economic evaluation, after adjustment for baseline covariates, the mean cost per participant in the treatment group was $92.2 more over the 8-week period (95% bias corrected CI: $38.70 to $149.20) compared with the waitlist control group (Table 5). Similarly, after adjustment, individuals in the treatment group had, on average, slightly higher QALYs than individuals in the control group (difference in QALYs of 0.010 [95% CI: 0.003 to 0.018], Table 5). In summary, participants randomized to receive treatment had, on average, slightly higher QALYs but incurred higher costs than participants allocated to the control group. The incremental cost-effectiveness ratio was $8,806 (95% CI: $2,849 to $39,522) which means that, on average, the intervention will produce one additional QALY for additional cost of $8,806. Uncertainty in the cost-effectiveness estimates is represented in Figure S1. The cost-effectiveness plane shows that treatment is very likely to be more costly but more effective. The CEAC shows the probability of the treatment being cost-effective at different WTP thresholds. There is 50% probability of treatment being cost-effective if the decision-maker is only willing to pay $8,806 per QALY (which is also the mean value of ICER) and it increases as the decision maker’s WTP increases. The CEAC shows that treatment is highly likely to be cost-effective at the commonly used willingness-to-pay threshold of $50,000/QALY in Australia (probability of being cost-effective is > 95%; Fenwick et al., 2004 and McCabe et al., 2008; Figure S1). Table 5. Adjusted Costs and QALYs for the Treatment and Control Groups at Posttreatment Mean costs ($) 95% Bias Corrected Confidence Interval ($) Mean QALYs 95% Bias Corrected Confidence Interval Treatment 229.5 184.9 - 276.4 0.102 0.044 - 0.139 Control 137.4 98.4 - 173.5 0.092 0.033 - 0.128 Difference 92.2 38.7 - 149.2 0.010 0.003 - 0.018 Note. Adjusted for baseline utility, baseline cost (in the cost equation) and history of mental health problems. QALYs; quality-adjusted life-years. 1 AUD = 0.937 USD.