Introduction 2006 2002 2002 2002 1999 1999 2002 2002 2005 2007 2000 2006 2007 2006 2005 d 2007 P 2007 In the current study, we will present the results of a systematic review of Internet-delivered CBT for health problems. In the review, we aim to establish for which health problems Internet-based CBT has been developed, and examined in randomized controlled or comparative trials, and whether these interventions were effective. We also examine the target groups and contents of these intervention, as well the quality of the studies. Methods Search strategy and selection of studies 2006 2004 2007 Quality assessment 2005 2005 1995 2005 We assessed the validity of the studies using four basic criteria: allocation to conditions is conducted by an independent (third) party; adequacy of random allocation concealment to respondents; blinding of assessors of outcomes; and completeness of follow-up data. Analyses We examined the characteristics of the target populations, the interventions, and the design of the included studies. d M c M e SD ec 1988 When sufficient effect sizes were available (at least three effect sizes examining the same outcome measure in the same health problem), we calculated pooled mean effect sizes. For these analyses, we used the computer program Comprehensive Meta-analysis (version 2.2.021), developed for support in meta-analysis. As we expected considerable heterogeneity, we decided to calculate mean effect sizes with the random effects model. In the random effects model, it is assumed that the included studies are drawn from ‘populations’ of studies that differ from each other systematically. 2003 I 2 2003 Results Included studies 1 Table 1 Selected characteristics of Internet-based cognitive behavioral interventions for health problems  Participants Intervention and conditions Study Health condition Recruitment Women (%) Age group (M) Conditions  N Intervention Contact Period Measurements Dropout (%) Country 2003 Headache Community 82 18–59 (40) 1. I-CBT + telephone 24 Psychoeducation, applied relaxation; problem solving; cognitive restructuring E-mail (at request) 6 weeks Pre, post 32 Sweden 2. I-CBT 20 Weekly telephone calls 2005 Tension-type, migraine-only or mixed headache  Community 83 NR (42) 1. I-CBT 39 Progressive muscle relaxation + cognitive stress coping therapy (tension-type), or autogenic training + PMR (migraine/mixed) No therapist contact 4 weeks Pre, post 38 US 2. Waiting-list 47 2000 Recurrent headache Community 68 ≥ 18 (37) 1. I-CBT 51 Psychoeducation, applied relaxation; problem solving; cognitive restructuring E-mail (at request) 6 weeks Pre, post 61 Sweden 2. Waiting-list 51 2006 Chronic pain + burn-out in patients on long-term sick leave  Community 90 18–65 (47) 1. I-CBT 30 Films + texts; psychoeducation + cognitive self-treatment (changing, coping with shame and guilt, depression, identity, etc.) Real live introduction meeting + weekly online sessions 20 weeks Pre, post, 1 year 8 Sweden 2. Waiting-list 30 2004 Chronic back pain  Community 63 18–65 (45) 1. I-CBT 25 Applied relaxation; physical exercise, coping strategies E-mail (at request) weekly telephone calls 8 weeks Pre, post, 3 months 8 Sweden 2. Waiting-list 32 2006 Pediatric recurrent pain/headache Community 64 9–16 (12) 1. I-CBT 25 Psychoeduation; relaxation; cognitive restructuring E-mail contact (5 times) + telephone contact (3 times) 7 weeks Pre, post, 3 months 21 Canada 2. Waiting-list 22 2002 Tinnitus Community 47 18–70 (48) 1. I-CBT 53 Psychoeducation; applied relaxation; positive imagery; advice on noise sensitivity; cognitive restructuring; behavioral sleep management. Weekly report on progress, weekly encouraging e-mail  6 weeks Pre, post, 1 year 41 Sweden 2. Waiting-list 64 2003 People with physical disabilities who feel lonely Community 53 ≥ 18 (34) 1. I-CBT 11 Psychoeducation on communication; self-observation, role-playing, confrontation, positive verbalizations; social skills and assertiveness. Weekly sessions on the Internet 12 weeks Pre, post, 4 months 14 Canada 2. Waiting-list 11 2006 Chronic diseases (heart, lung, or type 2 diabetes) Community 71 ≥ 18 (57) 1. I-CBT 457 Exercise programs; relaxation; cognitive restructuring; psychoeducation; physician-patient communication; healthy eating; fatigue management; problem solving  Web-based bulletin board discussion groups (trained peer moderators) 6 weeks Pre, post, 1 year 18 US 2. Care-as-Usual 501 2005 Early-stage breast cancer Clinical 100 NR (52) 1. I-CBT 32 Psychoeducation; coping advice for common physical symptoms such as pain and fatigue; structured coping-skills training exercises Bulletin board for asynchronous group discussion 12 weeks Pre, post 15 US 2. Waiting-list 30 2004 Insomnia Community 65 ≥ 18 (44)  1. I-CBT 54 Psychoeducation; sleep restriction, stimulus control, cognitive restructuring E-mail (at request) 5 weeks Pre, post 24 Sweden 2. Waiting-list 55 2006 Pediatric brain injury Clinical 38 5–16 (11) 1. I-CBT 20 Problem solving; communication; behavior management skills;  Videocontact with therapist 14 weeks Pre, post 2 US 2. I-information 20 Abbreviations: 2006 Eleven studies compared an Internet-based CBT intervention to a control condition, while one study compared two types of Internet-based CBT to each other (one with and one without weekly telephone calls). Nine of the eleven controlled studies used a waiting list control group, while one study used a care-as-usual control group, and the other one used an information control group. In all studies, participants were randomized to one of two conditions. In none of the studies was Internet-based CBT compared to a face-to-face intervention of another treatment. Six studies only presented pre-post data, while the other six also had a follow-up measurement (mean length of follow-up in these six studies was 7.67 months; standard deviation 4.76). Six studies were conducted in Sweden, four in the United States, and two in Canada. All included studies were conducted in the year 2000 or later (one in 2000 and another one in 2002, two in 2003, in 2004, and in 2005, and four in 2006). 2006 The target populations Three studies focused on patients suffering from pain, three on headache, and six on other health problems (tinnitus; physical disabilities; chronic diseases; breast cancer; insomnia; and pediatric brain injury). In ten of the twelve studies, patients were recruited through announcements on websites, referrals, and community recruitment. In the other two studies patients were recruited through screening of clinical samples. Ten studies were aimed at adults, two at children. None of the interventions were aimed at older adults, although three studies allowed older adults (≥70 years) to participate. The other studies on adults only included younger adults for participation or did not report that they used an age limit. The interventions The character of the interventions differed from each other. One group of interventions consisted of self-help materials on the Internet, with supporting e-mails or telephone calls (5 studies). In two studies the intervention consisted of self-help materials on the Internet, but without the supporting e-mails or calls. In the other studies, the core of the intervention consists of online contact between a therapist or moderator and the patients (individual or in groups). Most interventions contained psychoeducation on the specific problem, and different CBT modules such as cognitive restructuring, relaxation techniques, and social skills training. The duration of the interventions ranged between 4 and 20 weeks. Effects of the interventions 2 Table 2 Main outcomes of studies on Internet-based cognitive behavioral interventions for health problems  Health condition Comparison Main outcome Effect size 95% CI Pain 2006 Chronic pain and burnout Rehabilitation course versus waiting list control Functional limitations 0.48 −0.03–0.99 2004 Chronic back pain Internet-guided self-help versus waiting list control Coping with pain 0.79 0.22–1.36 2006 Pediatric recurrent pain/headache Internet-guided self-help versus waiting list control Pain 0.47 −0.24–1.18    POOLED a 0.25–0.92 Headache 2003 Headache Internet self-help with support versus self-help only Headache 0.38 −0.35–1.11 2005 Chronic headache Internet self-help versus waiting list control Headache 0.56 0.13–0.99 2000 Recurrent headache Internet self-help versus waiting list control Headache 0.19 −0.40–0.78 Other 2002 Tinnitus Internet CBT versus waiting list control Distress from tinnitus 0.26 −0.23–0.75 2003 Physical disabilities Goal-oriented CBT chat-group teletherapy versus waiting list control Loneliness 0.46 −0.45–1.37 2006 Chronic diseases  Online CBT workshops versus care-as-usual Health indicators (only 1 year FU) 0.10 −0.04–0.24 2005 Early-stage breast cancer Online CBT coping group versus waiting list control Health-related quality of life 0.22 −0.32–0.76 2004 Insomnia Internet CBT versus waiting list control    2006 Pediatric brain injury Online family problem solving therapy versus Internet resources  Parental mental health 0.70 0.05–1.35 a Z P Q I 2    P Q I 2    d 2000 d 2005 d d d d d Discussion 2007 2007 2006 2006 2006 2007 2006 2006 2001 2006 2005 2006 2000 1999 1994 2004 2003 There is no consensus yet among researchers about the way CBT should be presented on the Internet, although standards are emerging. Most interventions used a guided self-help format in which the treatment protocol is presented on the Internet and the patient works it through more or less independently. The patients are supported by brief contacts with therapists through e-mail or telephone. However, other studies use a more traditional format in that the patients go online at the same time as the therapist and have a more or less regular treatment session. Group treatments can also be delivered in such a way. Another difference between interventions concerns the additional elements on the Internet, apart from CBT. Some interventions have combined the cognitive behavioral interventions with other components, such as psychoeducation, films and texts to read, and a forum for users of the website. Other interventions do not provide such extras. Our review showed up several other important limitations of the current research in this area. First, most studies used waiting list control groups, and only very few used a care-as-usual or another control group. Subjects in waiting list control groups probably do not take constructive action to reduce their problems themselves during the waiting period, because they are expecting professional help in the future. This may result in an overestimation of the effects of an intervention, because there may be less spontaneous recovery. Second, most studies recruited participants through the community and through other websites. This is not a problem for interventions that target the general population. But when such an intervention is effective this does not automatically mean that it is also effective in clinical settings. Subjects who are responding to community recruitment are probably very motivated which may improve their results compared to subjects who receive treatment. Third, none of the twelve identified trials compared Internet-based treatments to face-to-face or other treatments. This is, however, an important issue, because only direct comparisons can give evidence about the comparative effects of Internet-based treatments compared to more traditional treatments and the type of patients who can benefit from it. Fourth, most studies were aimed at adults. Only two studies were aimed at children and adolescents, while these groups are probably the most familiar with the Internet. None of the studies were specifically aimed at older adults, while they suffer most from health conditions. Future research should focus on these limitations of current research. More studies are needed with care-as-usual or other control groups, clinical recruitment strategies, comparisons with face-to-face treatments, and children or older adults as target populations. More research is also needed to examine how CBT should be presented on the Internet, and to examine reasons and solutions to the relatively high drop-out rates in several studies. Finally, it is also important to study how Internet-administered CBT can be integrated in stepped-care models of care. This review has several limitations. First, the number of included studies is still very small. And the number of studies examining specific health problems is too small to integrate the results of these studies statistically into a meta-analysis. Second, the quality of the included studies is not optimal. Third, the drop-out rates reported are high in some studies. This is a concern for this type of intervention, as patients can very easily withdraw from the intervention. Remarkably, the studies in which more traditional therapies (live sessions with therapists) are delivered through the Internet have the lowest drop-out rates. Despite these limitations, however, there is no doubt that the number of studies in this area will increase considerably in the next few years, while the promising results of the studies in this review indicate that the Internet will assume a major role in the delivery of CBT to patients with health problems.