title: Predictors of outcome in Internet-based cognitive behavior therapy for severe health anxiety.
abstract: Internet-based cognitive behavior therapy (CBT) for severe health anxiety can be effective, but not all patients achieve full remission. Under these circumstances, knowledge about predictors is essential for the clinician in order to make reliable treatment recommendations. The primary aim of this study was to investigate clinical, demographic, and therapy process-related predictors of Internet-based CBT for severe health anxiety. We performed three types of analyses on data from a sample comprising participants (N = 81) who had received Internet-based CBT in a randomized controlled trial. Outcomes were a) end state health anxiety, b) improvement in health anxiety (continuous change scores), and c) clinically significant improvement. Outcomes were assessed at six-month follow-up. The results showed that the most stable predictors of both end state health anxiety and improvement were baseline health anxiety and depressive symptoms. Treatment adherence, i.e. the number of completed treatment modules, also significantly predicted outcome. Notably, health anxiety at baseline was positively associated with symptom improvement while depressive symptoms was negatively related to improvement. Demographic factors were largely without significant impact on end state symptoms or improvement. We conclude that baseline symptom burden and adherence to treatment have strong predictive effects in Internet-based CBT for severe health anxiety.
authors.affiliation: Department of Clinical Neuroscience, Division of Psychiatry, Karolinska Institutet, Retzius väg 8, SE-171 77 Stockholm, Sweden; Department of Clinical Neuroscience, Osher Center for Integrative Medicine, Karolinska Institutet, Stockholm, Sweden; Department of Clinical Neuroscience, Division of Psychology, Karolinska Institutet, Stockholm, Sweden. Electronic address: kire.hedman@ki.se.
authors.forename: Erik
authors.initials: E
authors.lastname: Hedman
authors.forename: Nils
authors.initials: N
authors.lastname: Lindefors
authors.forename: Gerhard
authors.initials: G
authors.lastname: Andersson
authors.forename: Erik
authors.initials: E
authors.lastname: Andersson
authors.forename: Mats
authors.initials: M
authors.lastname: Lekander
authors.forename: Christian
authors.initials: C
authors.lastname: Rück
authors.forename: Brjánn
authors.initials: B
authors.lastname: Ljótsson
mesh_terms: D000328:Adult; D000368:Aged; D001007:Anxiety / Q000150:complications / Q000523:psychology / Q000628:therapy*; D015928:Cognitive Behavioral Therapy / Q000379:methods*; D003863:Depression / Q000150:complications / Q000628:therapy; D005260:Female; D006304:Health Status; D006801:Humans; D020407:Internet; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance; D013813:Therapy, Computer-Assisted / Q000379:methods; D016896:Treatment Outcome
keywords: Cognitive behavior therapy; Internet; Predictors; Severe health anxiety