هزینه اثربخشی رفتاردرمانی شناختی مبتنی بر اینترنت برای اختلال وسواس: نتایج حاصل از یک مطالعه کنترل شده تصادفی

Obsessive-compulsive disorder (OCD) is a common and disabling disorder. Although evidence-based psychological treatments exists, such as cognitive behavior therapy (CBT), the cost-effectiveness of CBT has not been properly investigated. In this trial, we used health economic data from a recently conducted randomized controlled trial, where 101 OCD patients were allocated to either internet-based CBT (ICBT) or control condition (online support therapy). We analyzed treatment effectiveness in relation to costs, using both a societal- (including all direct and indirect costs) and a health care unit perspective (including only the direct treatment costs). Bootstrapped net benefit regression analyses were also conducted, comparing the difference in costs and effects between ICBT and control condition, with different willingness-to-pay scenarios. Results showed that ICBT produced one additional remission for an average societal cost of $931 and this figure was even lower ($672) when narrowing the perspective to treatment costs only. The cost-utility analysis also showed that ICBT generated one additional QALY to an average price of $7186 from a societal perspective and $4800 when just analyzing the treatment costs. We conclude that ICBT is a cost-effective treatment and the next step in this line of research is to compare the cost-effectiveness of ICBT with face-to-face CBT.

Although cognitive behavior therapy (CBT) for obsessive-compulsive disorder (OCD) has shown efficacy in numerous randomized trials, with overall large effect sizes (Gava et al. 2007), treatment availability is still low and only a fraction (5–8%) of the patients actually receives this treatment (Blanco et al., 2006 and Torres et al., 2007). An Internet-survey by Marques et al. (2010) also showed that, of those OCD patients who had received psychological treatments, the majority (67%) had actually received non-evidenced based treatments. Both financial- and logistic factors were found to be significant barriers to treatment seeking and many patients reported stigma-related reasons for not seeking help, such as shame and fear of discrimination. Another reason for the low accessibility of CBT could be the current lack properly trained therapists within the health care system (Larsson et al., 2010, Mataix-Cols and Marks, 2006 and Shapiro et al., 2003). Thus, although CBT is effective in reducing OCD symptoms, it is not accessible for the majority of those in need, a problem referred to as the treatment-demand gap (Kohn, Saxena, Levav, & Saraceno, 2004). One possible solution to overcome the problem of treatment accessibility could be to use internet-based CBT (ICBT; Andersson, 2009). ICBT mimics traditional CBT in every respect, the only difference being the way the treatment is delivered. In ICBT, the patient, instead of going to a clinic, logs on to a secure website and works with written self-help materials and homework assignments, which are closely monitored by a clinician. As in regular CBT for OCD, the main treatment component is exposure with response prevention (ERP), which the patients are instructed to practice repeatedly until fear, rituals and avoidance subside (Abramowitz, Taylor, & McKay, 2009). ICBT has been shown to be effective for several other psychiatric and somatic conditions (Hedman, Ljotsson, & Lindefors, 2012) and the treatment effects are in general much better when supported by a therapist (Cuijpers et al., 2011 and Cuijpers et al., 2010). ICBT carries important advantages compared to conventional face-to-face CBT, primarily that that it can overcome geographical and practical barriers for the patient and also that the therapist can treat four to five times more patients (Andersson, 2009). There are today a handful of studies showing that ICBT is an effective treatment for OCD. Two of these are uncontrolled studies (Andersson et al., 2011 and Wootton et al., 2011) and two are randomized controlled trials (Andersson et al. 2012; Wootton et al. 2013), showing effect sizes similar to those obtained in face-to-face CBT and also sustained long-term effects (Andersson et al. 2014). Thus, ICBT seems to be an acceptable and effective treatment that may increase accessibility for OCD patients to receive effective care. Cost-effectiveness analysis is a form of health economic evaluation where the treatment effects are analyzed in relation to the associated costs. There are two ways of doing cost-effectiveness analysis. One way is to use symptom specific measures and relate this to the cost change, that is, how much must the society to be willing to pay for one additional remission. Another way to estimate the cost-effectiveness of a treatment is to use a generic outcome, such as quality of life (also known as cost-utility analysis). Research about cost-effectiveness is important because it aids policy-makers in deciding what treatments that give the optimal output, in relation to both costs and efficacy. Assuming that health care resources are limited, cost-effectiveness studies thus enables that more patients can achieve clinical improvement and increased quality of life (Drummond, Sculpher, Torrence, O’Brien, & Stoddart, 2005). There is no consensus regarding the definition of a cost-effective treatment, but in the western world, a treatment that can generate an additional quality adjusted life year (QALY) at a cost below 50 000 USD is generally considered cost-effective (Grosse, 2008). ICBT has been shown to be a highly cost-effective treatment for a range of clinical disorders (Hedman et al., 2012a and Hedman et al., 2011) but research regarding cost-effectiveness of ICBT for OCD is lacking and health economic evaluation of face-to-face CBT for OCD is scarce. An early study by Ginsberg and Marks (1977) evaluated the societal cost impact of a 16 h CBT program and found a 35–61% decrease in medical consumption after receiving treatment. Furthermore, the intervention was associated with reduced time off work for both patients as well as relatives. A more recent study by McCrone et al. (2007) compared computer-aided CBT (CCBT) with face-to-face CBT. Results showed that although CCBT showed less efficacy compared to face-to-face CBT, the cost-effectiveness benefited CCBT due to lower treatment costs. However, a major limitation in this study was that societal costs were excluded from the analysis, for example, other medical costs sick leave and work cut-back. In recent trial by Tolin, Diefenbach, and Gilliam (2011), the authors evaluated a stepped care program (first low intensive treatment, then regular face-to-face CBT) vs. regular treatment (i.e. 17 sessions face-to-face CBT). Results showed that both groups had significant responder rates (67% in the stepped care vs. 50% in the regular ERP group) but the stepped care group was associated with both lower direct treatment- as well as indirect societal costs (Diefenbach and Tolin, 2013 and Tolin et al., 2011). There is, to our knowledge, no published data on the cost-effectiveness of ICBT for OCD. The aim of this study was therefore to investigate this issue from a societal as well as from a care provider perspective. We hypothesized that ICBT would be cost-effective compared to a basic attention control intervention.

3. Results 3.1. Clinical efficacy A large between-group effect size (Cohen´s d=1.12) was observed at post-treatment on the Y-BOCS which favored the ICBT group. There were 60% (95% CI 0.69–1.53) responders in the ICBT group at post-treatment, compared to only 6% (95% CI 1–17) in the control condition. This difference was significant using a logistic regression model (B=3.18, Z=4.80, p <.001). The mean score on the EQ-5D at pre-treatment for the ICBT group was .80 (SD=.15) and .84 (SD=.12) in the control condition. The corresponding figure at post-treatment was .87 (SD=.14) in the ICBT group and .84 (SD=.12) in the control condition. This difference came out significant in the linear regression analysis (B=0.07, t=3.06, p <.01). 3.2. Costs Detailed information of the economic data at pre-treatment, post-treatment and at follow-up is presented in Table 3. There were no significant between-group cost differences except for the total net costs (including intervention) associated with the ICBT treatment (Z=-3.37, p <.001). Table 3. Mean costs ($). Pre-treatment Post-treatment 4-Month follow-up ICBT(SD) Control(SD) ICBT(SD) Control(SD) P-value a ICBT(SD) Direct medical 334(460) 695(69) 342(480) 169(285) .21 136(234) Health care visits 321(458) 681(1,242) 330(475) 169(285) .12 127(234) Medications 13(34) 14(26) 12(21) 11(24) .46 8(22) Direct non-medical 70(148) 114(287) 342(480) 169(285) .74 136(234) Indirect non medical 1,500(2,422) 1,240 (2,190) 732(1,595) 771(1,688) .62 625(1,166) Unemployment 602(2,064) 591(2,045) 307(1,505) 301(1,491) .98 371(1,114) Sickleave 138(578) 203(722) 85(281) 68(292) .51 39(127) Workloss 684(1399) 388(872) 270(622) 348(841) .96 187(473) Domestic 75(156) 58(108) 69(122) 53(123) .40 27(57) Total (excl. Intervention costs) 1,905(2,447) 2,049(2,793) 1,165(1,707) 1,032(1,761) .19 789(1,206) Therapist cost 423(221) 60(50) <.001 Total costs incl therapist cost 1,594(1,720) 1,092(1,764) <.001 789(1,206) Abbreviations: ICBT: Internet-based Cognitive Behavior Therapy SD: Standard Deviation a Significance testing were conducted at post-treatment using non-parametric Mann–Whitney tests. Table options 3.3. Cost-effectiveness 3.3.1. ICER of one additional remission When taking a societal perspective, the bootstrapped regression analyses estimated the ICER to 503/0.54=$931. This means that, from a societal perspective, one additional remission can be achieved for a mean cost of $931. The corresponding ICER when taking a health care unit perspective was reduced to 363/0.54=$672. As seen in Fig. 2, ICBT had a 90% probability of being cost-effective using a societal perspective given a willingness-to-pay of $2600. When narrowing the perspective to health care unit costs, the corresponding figure was reduced to $900. Full-size image (34 K) Fig. 2. Cost-effectiveness acceptability plane with remission as outcome variable. Note: Societal perspective means that all societal costs are included in the calculation. Health care unit perspective only includes the direct treatment costs. Abbreviations: ICBT: Internet-based cognitive behavior therapy. Figure options 3.4. ICER of one additional QALY We repeated the analyses but instead using the EQ-5D as outcome. This analysis gave a cost-utility estimate of 503/0.07=$7186 from a societal perspective. The corresponding figure for a health care unit perspective was 336/0.07= $4800. As seen in Fig. 3, ICBT was a cost-effective alternative with 90% probability given a willingness to pay of $26000. The corresponding figure from a health care provider perspective was $9000. Full-size image (35 K) Fig. 3. Cost-effectiveness acceptability plane with QALY as outcome variable. Note: Societal perspective means that all societal costs are included in the calculation. Health care unit perspective only includes the direct treatment costs. Abbreviations: ICBT: Internet-based cognitive behavior therapy, QALY: Quality adjusted life year.