- LBP low back pain, sd standard deviation, IQR interquartile range
- *Primary outcome
- aThe value ranges for LBP specific disability are based on the Roland-Morris Disability Questionnaire; higher values indicate higher levels of disability. Pain severity is measured using a modified version of the characteristic pain intensity subscale of the Graded Chronic Pain Scale, higher values indicate higher levels of pain. Fear avoidance beliefs will be measured using the Fear Avoidance Beliefs Questionnaire physical activity subscale, higher values reflect greater fear avoidance. AQoL-4D utility scores are anchored at death (0.00) and full health (1.00) and scaled from − 0.04 to 1.00 where negative utility values designate states worse than death
- bAdjusted effects from models fitted using Generalised Estimating Equations with exchangeable correlation structure and robust variance estimation to allow for clustering within practices. Effect estimates are the difference in means, with the exception of the outcome ‘X-ray occurred’, where the effect estimate is an odds ratio. Models adjusted for pre-specified confounding variables noted in Fig. 2 of the trial protocol [22], except for the confounding variables ‘number visits for this episode of acute low back pain’ and ‘≥ 1 X-ray low back pain previous 12 mths’ (see Additional file 1)
- cRD risk difference. RD calculated from marginal probabilities. Confidence intervals were calculated using a pairwise comparison of margins after fitting a GEE model using Stata, allowing for clustering of observations within practices
- dModelled with an independent correlation structure
- eAQoL-4D utility scores
Trials