The Impacts of Chronic Non-specific Low Back Pain on Cognitive Functions of Older Adults: A Longitudinal Study

11-point numerical rating scale, ranged from 0 to 10, higher scores indicate higher pain intensity.

Perform the following MRI sequences: T1-weighted, T2-weighted, DTI (diffusion tensor imaging), resting-state fMRI, and task-related fMRI.

The Chinese version of the short Depression Anxiety Stress Scales, scores ranged from 0 to 13, higher scores for each domain (depression, anxiety, and stress) indicate more respective problems.

The Hong Kong Chinese Version of the Roland-Morris Disability Questionnaire has 24 items. Scores ranged from 0 to 24, higher scores indicate worse disability.

The More Odd Shifting task, It requires participants to switch between different mental sets or rules, such as identifying odd numbers or shifting between different categories. Better response accuracy indicates better cognitive flexibility

The Modified Wisconsin Card Sorting Test, more correct matching of cards indicate better perseveration and abstract reasoning.

The Verbal Digits Forward and Backward Test, more correct recall of digits indicate better working memory and executive function

The Trail Making Tests, a neuropsychological test of visual attention and task switching, completing the trail correctly within a shorter period of time means better cognitive flexibility.

Go/NoGo task, more response accuracy indicates better control of inhibition.

The Chinese version of Pain Catastrophizing Score. The scores ranged from 0 to 13, higher scores indicate more pain catatrophizing thought.

Fatigue, Resistance, Ambulation, Illness, and Loss, the presence of 3 of 5 item characteristics indicate the presence of frailty, scores ranged from 0 to 5. Lower scores mean more frailty.

Pittsburgh Sleep Quality Index. It has 7 domains to measure sleep quality , sleep latency, sleep duration, habital sleep efficiency, sleep disturbances, use of sleep medication, and daytime dysfunction. Scores ranged from 0 to 21, higher scores indicate poorer sleep quality.

Hong Kong Montreal Cognitive Assessment. It is a cognitive screening tool specifically adapted for Chinese older adults in Hong Kong. It is designed to detect mild cognitive impairment and dementia. A score < 26 suggests participant has mild cognitive impairment.

Short Physical Performance Battery (SPPB). It consists of three components: balance test, gait speed test, and chair stand test. The SPPB scores range from 0 to 12. Individuals with SPPB scores between 10 and 12 can exercise at home and in the community while those with more severe mobility limitations (scores < 10) require further assessment and supervision for exercise.

Timed Up and Go (TUG) test. It measures the time taken for an individual to rise from a chair, walk 3 meters, turn around, walk back, and sit down again. The TUG test helps identify individuals at risk of falls and mobility impairments. A shorter completion time indicates a better balance and functional mobility.