A randomised controlled trial evaluating an internet-based cognitive behavioural therapy (iCBT) program for health anxiety

INTERVENTION: The internet Health Anxiety Program program comprises 6 lessons completed over 12 weeks. It includes all treatment components typically seen in face­‐to­‐face cognitive behavioural therapy (CBT) (the first­‐line treatment for severe health anxiety). One lesson will be completed every 7 to 14 days (it will become available after the preceding lesson has been completed, with a minimum of 5 days between lessons and a maximum of 14 days). Each lesson will take approximately 20‐30 minutes to complete. Participants will have access to summaries of each lesson, homework exercises, extra resources, email contact from the clinician (registered clinical psychologist) after completion of the first two lessons, then as required. The participant is also able to email or phone the clinician at any point during the trial as required. The participant completes a measure of psychological distress before each lesson and if their scores increase by one or more standard deviations the clinician is automatically alerted and initiates contact with the participant by phone or email. Strategies used to improved adherence to intervention protocols and procedures for monitoring adherence include: automated email reminders, monitoring the downloading of homework, collection of data on how long participants spent reading lessons and practicing skills. CONDITION: Health Anxiety Illness Anxiety Disorder Somatic Symptom Disorder PRIMARY OUTCOME: Mean score on the Short Health Anxiety Inventory SECONDARY OUTCOME: Changes in hypervigilance to bodily sensations according to the mean scores on the adapted version of the Body Vigilance Questionnaire. Changes in intolerance of uncertainty according to the mean score on the Intolerance of Uncertainty 12‐item (IUS‐12). Changes in mindful awareness and attention according to the mean scores on the Mindful Awareness and Attention Scale (MAAS). Changes in symptoms of 'cyberchondria' or excessive internet searching, according to mean scores on the Cyberchondria Severity Scale (CSS). Changes in unhelpful beliefs about body and health according to mean scores on the Cognitions about Body and Health Questionnaire (CABAH) Changes in worry behaviours (e.g., checking and reassurance‐seeking) according to the mean scores on the Brief Worry Behaviours Questionnaire. Level of functional impairment and disability according to mean score on the World Health Organisation Disability Assessment Schedule (WHODAS‐II). Mean score on the Patient Health Questionnaire 9‐item (PHQ‐9) Perceived health status according to the proportion of participants who report improvements on the Self‐Rated Health questionnaire. Proportion of participants with a change in the frequency of service use and days out of role according to the Service Use and Days out of Role Questionnaire (SUDOR), and the Service Use Inventory adapted from the Australian National Health and Wellbeing Survey. Severity of psychological distress according to mean scores on the Kessler‐10 (K10) Treatment Satisfaction according to the Treatment Satisfaction Questionnaire. INCLUSION CRITERIA: * Self‐identified as suffering from excessive health anxiety. * Meet criteria for either Illness Anxiety Disorder (IAD) or Somatic Symptom Disorder (SSD) according to the Anxiety Disorders Interview Schedule for DSM‐5 (ADIS‐5). * Australian resident status * At least 18 years of age * Access to a computer, printer, and the internet * If taking medication, must have been taking the same dose for at least 1 month and not intend to change that dose during the course of the program. * Prepared to provide name, phone number, and address, and to provide the name and phone number of a local general practitioner. * Willing to provide informed consent. * Willing to provide consent for study team to notify their GP of their participation in this project.