Evaluation of a Theory-Informed Implementation Intervention for the Management of Acute Low Back Pain in General Medical Practice: The IMPLEMENT Cluster Randomised Trial

Introduction: This cluster randomised trial evaluated an intervention to decrease x-ray referrals and increase giving advice to stay active for people with acute low back pain (LBP) in general practice. Methods: General practices were randomised to either access to a guideline for acute LBP (control) or facilitated interactive workshops (intervention). We measured behavioural predictors (e.g. knowledge, attitudes and intentions) and fear avoidance beliefs. We were unable to recruit sufficient patients to measure our original primary outcomes so we introduced other outcomes measured at the general practitioner (GP) level: behavioural simulation (clinical decision about vignettes) and rates of x-ray and CT-scan (medical administrative data). All those not involved in the delivery of the intervention were blinded to allocation. Results: 47 practices (53 GPs) were randomised to the control and 45 practices (59 GPs) to the intervention. The number of GPs available for analysis at 12 months varied by outcome due to missing confounder information; a minimum of 38 GPs were available from the intervention group, and a minimum of 40 GPs from the control group. For the behavioural constructs, although effect estimates were small, the intervention group GPs had greater intention of practising consistent with the guideline for the clinical behaviour of x-ray referral. For behavioural simulation, intervention group GPs were more likely to adhere to guideline recommendations about x-ray (OR 1.76, 95%CI 1.01, 3.05) and more likely to give advice to stay active (OR 4.49, 95%CI 1.90 to 10.60). Imaging referral was not statistically significantly different between groups and the potential importance of effects was unclear; rate ratio 0.87 (95%CI 0.68, 1.10) for x-ray or CT-scan. Conclusions: The intervention led to small changes in GP intention to practice in a manner that is consistent with an evidence-based guideline, but it did not result in statistically significant changes in actual behaviour. Trial Registration: Australian New Zealand Clinical Trials Registry ACTRN01260600009853

Attentional capture for tool images is driven by the head end of the tool, not the handle

Tools afford specialized actions that are tied closely to object identity. Although there is mounting evidence that functional objects such as tools capture visuospatial attention relative to non-tool competitors, this leaves open the question of which part of a tool drives attentional capture. Here, we used a modified version of the Posner cueing task to determine whether attention is oriented towards the head versus the handle of realistic images of common elongated tools. We compared cueing effects for tools with control stimuli that consisted of images of fruit and vegetables of comparable elongation to the tools. Critically, our displays controlled for lower-level influences on attention that can arise from global shape asymmetries in the image cues. Observers were faster to detect low-contrast targets positioned near the head end versus the handle of tools. As expected, no lateralized performance bias was observed for the control stimuli. In a follow-up experiment we confirmed that the bias towards tool heads was not due to inhibition of return as a result of early attentional orienting towards tool handles. Finally, we confirmed that real-world exemplars of the tools in the cueing studies were associated more strongly with specific grasping patterns than the elongated fruits and vegetables. Together, our results demonstrate that affordance effects on attentional capture are driven by the head end of a tool. Prioritizing the head end of a tool is adaptive because it ensures that the most relevant region of the object takes priority in selecting an effective motor plan