This study aims to evaluate the effectiveness of two communication interventions, compared to standard app notifications, in increasing adherence to a mobile health app among individuals with chronic low back pain. The main question it aims to answer is:

Do phone calls or text messages increase adherence compared to app notifications in patients receiving a digital health intervention for chronic back pain?

Participants will:

A) Receive pain education and clinical hypnosis via a mobile app for managing chronic LBP; B) Will be contacted up to twice via phone call or text message, or they will only receive standard notifications from the app.

Inclusion Criteria:

• Experiencing non-specific chronic low back pain (LBP), defined as pain between the 12th rib and the buttock crease.
• LBP with or without leg pain (in case of leg pain, LBP is worse than leg pain).
• Currently consulting with a general practitioner for their non-specific chronic LBP across Australia.
• Mean pain intensity score on the Numeric Rating Scale ≥ 3/10 in the past week.
• A score of at least moderate on question 8 of the physical functioning component of the SF-36 questionnaire.
• Access to a mobile device with minimal requirements to download the study app (300MB).
• An internet connection to access the mobile app functionalities.
• Able to understand English via reading and audio materials.
• Randomised to experimental group at NOTUS Trial.

Exclusion Criteria:

• Known or suspected specific spinal (e.g., radiculopathy, fracture) or specific non-spinal non- (e.g., tumour, infection) pathology.
• Less than six months post-spinal surgery.
• Scheduled for major surgery during the program or the follow-up period.
• Known or suspected serious psychiatric condition not being treated by a health professional that would impact adherence to the trial activities.
• Known or suspected sight or hearing problems that would limit access to the intervention components (reading and listening using headphones).

De-identified individual participant data will be made available to interested researchers only upon reasonable request and once the proposed research project has received separate ethics approval from a Human Research Ethics Committee.

Request to the data custodian, the Principal Investigator (j.mcauley@neura.edu.au).

Data will be made available after the publication of the study reports. There is no end date for the availability of study data.

General practitioners and statisticians will be blind to group allocation. Blinding will be maintained for the entire duration of the trial until all data have been collected, and data analysis and interpretation have been completed. The personnel involved in the daily operations of the trial (e.g., research assistants and investigators who will provide possible technical support to participants and trial managers) will be unblinded to group allocation and will not be involved in the analyses.