HEalth literacy in Low back Pain - the HELP! media intervention study: Statistical Analysis Plan

The HELP study aims to evaluate the effectiveness of a media-led intervention that includes evidence-based information on the management of low back pain (LBP), distributed and broadcasted at point-of-care in primary care settings (i.e. General Practice clinic waiting rooms), to change beliefs and behaviour about LBP management. The effect of the intervention on patients beliefs and attitudes about LBP management will be evaluated using The Back Beliefs Questionnaire (BBQ) and the Back Pain Attitudes Questionnaire (Back-PAQ) scores. Change in medical practitioner behaviour and delivery of care (i.e. prescription of opioid medication, referrals for medical imaging and allied health care) will be assessed using administrative data. The statistical analysis plan pre-specifies the method of analysis for the key outcome variables collected in the study. The BBQ and Back-PAQ scores will estimate the mean difference (MD) in each score between the intervention arm and the usual care arm obtained from a linear mixed model. Using a similar model, analysis of the GP clinic data will report the differences in proportions of opioid medication, and referrals to medical imaging and allied health care between the intervention arm and usual care arm.