Table 1.
Baseline characteristics
| Opioid (n = xxx) | Placebo (n = xxx) | |
|---|---|---|
| Female | n/N (%) | n/N (%) |
| Age (years) | xx.x (SD), n | xx.x (SD), n |
| BMI (kg/m2) | xx.x (SD), n | xx.x (SD), n |
| Location of pain | ||
| Back | n/N (%) | n/N (%) |
| Neck | n/N (%) | n/N (%) |
| Both | n/N (%) | n/N (%) |
| Days since onset of pain | Med (IQR) | Med (IQR) |
| Number of previous episodes of pain | Med (IQR) | Med (IQR) |
| Currently employed | n/N (%) | n/N (%) |
| Employment classification | n/N (%) | n/N (%) |
| Manager | n/N (%) | n/N (%) |
| Technician and trade worker | n/N (%) | n/N (%) |
| Clerical and administrative | n/N (%) | n/N (%) |
| Machinery operator or driver | n/N (%) | n/N (%) |
| Professional | n/N (%) | n/N (%) |
| Community or personal services worker | n/N (%) | n/N (%) |
| Sales worker | n/N (%) | n/N (%) |
| Labourer | n/N (%) | n/N (%) |
| Compensable back/neck pain | n/N (%) | n/N (%) |
| Household income/week (years) (AUD) | ||
| No income | n/N (%) | n/N (%) |
| $1–$799 ($1–$41,599) | n/N (%) | n/N (%) |
| $800–$1999 ($41,600–$103,999) | n/N (%) | n/N (%) |
| $2000–$3999 ($104,000–$207,999) | n/N (%) | n/N (%) |
| $4000 or more ($208,000 or more) | n/N (%) | n/N (%) |
| Chose not to answer | n/N (%) | n/N (%) |
| Health insurance status | ||
| None | n/N (%) | n/N (%) |
| Private hospital only | n/N (%) | n/N (%) |
| Private extras only | n/N (%) | n/N (%) |
| Private hospital and extras | n/N (%) | n/N (%) |
| DVA | n/N (%) | n/N (%) |
| Chose not to answer | n/N (%) | n/N (%) |
| Pain severity (BPI pain severity subscale average) (x/10) | Mean (SD) | Mean (SD) |
| Disability (BPI pain interference subscale average) (x/10) | Mean (SD) | Mean (SD) |
| Condition-specific disability | ||
| Back – RMDQ (0–24) | N = mean (SD) | N = mean (SD) |
| Neck – NDI (0–50) | N = mean (SD) | N = mean (SD) |
| Quality of life – Physical SF12v2 | Mean (SD) | Mean (SD) |
| Quality of life – Mental SF12v2 | Mean (SD) | Mean (SD) |
| Global perceived effect scale (−5 to 5) | Mean (SD) | Mean (SD) |
| Healthcare utilisation prior to enrolment | ||
| Took prescription opioid medication for back/neck pain | n/N (%) | n/N (%) |
| Saw a physiotherapist | n/N (%) | n/N (%) |
| Had imaging | n/N (%) | n/N (%) |
| Other healthcare | n/N (%) | n/N (%) |
| On medication for other pain or mood, sleeping, seizures or mental health problems during this episode of pain | n/N (%) | n/N (%) |
BPI Brief Pain Inventory, RMDQ Roland-Morris Disability Questionnaire, NDI Neck Disability Index, SF12v2 Short form 12, version 2