Table 2 Secondary outcomes

Self-reported physical activity levels

Global Physical Activity Questionnaire (GPAQ) [31]

The GPAQ assesses intensity-specific physical activity participation in 3 domains (activity at work, travel to and from places, recreational activities), and sedentary behaviour [31].

Objective physical activity levels

Axivity tri-axial accelerometer [32], assessed over a 7-day period

The device accurately estimates how physically active a person has been throughout the day using an accelerometer. The outcomes are overall physical activity, categorised according to intensity (sedentary, light, moderate, vigorous) and quantified as the average counts per minute of acceleration during the time the accelerometer is worn.

Function

Patient Specific Functional Scale (PSFS) [33]

At baseline, participants will be asked to self-select three activities they have difficulty performing due to their LBP. Each activity will be scored on an 11-point scale at each timepoint, with 0 representing ‘unable to perform activity’ and 10 representing ‘able to perform activity at the same level as before injury or problem.’ The scores for the three activities will be summed, giving a total score ranging from 3 to 30.

Pain intensity (i.e., mean intensity of LBP over the past fortnight)

Numerical Rating Scale (NRS) [34]

The NRS is an 11-point scale, scored on a scale of 0 to 10, with 0 representing ‘no pain’ and 10 representing ‘worst possible pain.’

Disability

Roland–Morris Disability Questionnaire (RMDQ) [35]

The RMDQ consists of 24 items and total scores range from 0 to 24, with higher scores indicating higher disability levels.

Quality of life

Assessment of Quality of Life questionnaire (AQoL-8D) [36, 37]

The AQoL-8D consists of 35 items across 8 dimensions, with higher scores within each dimension corresponding to poorer quality of life. Utility weighted AQoL-8D scores will be used to estimate quality-adjusted life years (QALYs) for the cost-effectiveness analysis [38].

Self-management behaviours

Questionnaire specifically designed for this study

Examples of self-management behaviours will include, but are not limited to, the use of heat packs or hot showers for LBP, massage (not delivered by a professional), brace or support strapping/tape, topical creams/gels, physical activity and exercise, relaxation, meditation, mindfulness techniques, and walking aids specifically used to manage LBP.

Medication use

Questionnaire specifically designed for this study

Data on the use of medications for managing LBP, including type (i.e., paracetamol, non-steroidal anti-inflammatory drugs, opioids), dosage, and whether the medication was prescribed by a medical or health professional, will be collected on a fortnightly basis.

Sleep quality

Pittsburgh Sleep Quality Index (PSQI) [39]

The PSQI is an 18-item self-reported questionnaire assessing sleep disturbances in the last month. The total score is composed of a sum of scores in 7 different domains and ranges from 0 to 21, with higher scores indicating poorer sleep quality.

Attitudes regarding use of pain medications

Short-form Pain Medication Attitudes Questionnaire (PMAQ-14) [40]

The PMAQ-14 consists of 14 items across 7 areas of concern for users of pain medications (addiction, need, scrutiny, side effect, tolerance, mistrust of doctors, withdrawal). Each item is scored on a 6-point scale with 0 representing never true and 5 representing always true.

Beliefs about back pain

Back Beliefs Questionnaire (BBQ) [41]

The BBQ consists of 14 items and total scores range from 9 to 45, with lower scores indicating more negative beliefs about back pain.