Dr Kate O'Brien

There has been a proliferation of digital health interventions (DHIs) targeting dietary in-take. Despite their potential, the effectiveness of DHIs are thought to be dependent, in part, on user engagement. However, the relationship between engagement and the effectiveness of dietary DHIs is not well understood. The aim of this review is to describe the association between DHI engagement and dietary intake. A systematic search of four electronic databases and grey literature for records published before December 2019 was conducted. Studies were eligible if they examined a quantitative association between objective measures of engagement with a DHI (subjective experience or usage) and measures of dietary intake in adults (aged = 18 years). From 10,653 citations, seven studies were included. Five studies included usage measures of engagement and two examined subjective experiences. Narrative synthesis, using vote counting, found mixed evidence of an association with usage measures (5 of 12 associations indicated a positive relationship, 7 were in-conclusive) and no evidence regarding an association with subjective experience (both studies were inconclusive). The findings provide early evidence supporting an association between measures of usage and dietary intake; however, this was inconsistent. Further research examining the association between DHI engagement and dietary intake is warranted.

Objective: To assess the effectiveness of weight-loss interventions on pain and disability in people with knee and hip osteoarthritis (OA) and spinal pain. Design: Intervention systematic review. Literature Search: Twelve online databases and clinical trial registries. Study Selection Criteria: Randomized controlled trials of any weight-loss intervention (eg, diet, physical activity, surgical, pharmaceutical) that reported pain or disability outcomes in people with knee or hip OA or spinal pain. Data Synthesis: We calculated mean differences or standardized mean differences (SMDs) and 95% confidence intervals (CIs). We used the Cochrane risk of bias tool to assess risk of bias and the Grading of Recommendations Assessment, Development, and Evaluation tool to judge credibility of evidence. Results: Twenty-two trials with 3602 participants were included. There was very low- to very low-credibility evidence for a moderate effect of weight-loss interventions on pain intensity (10 trials, n = 1806; SMD, -0.54; 95% CI: -0.86, -0.22; I2 = 87%, P<.001) and a small effect on disability (11 trials, n = 1821; SMD, -0.32; 95% CI: -0.49, -0.14; I2 = 58%, P <.001) compared to minimal care for people with OA. For knee OA, there was low- to moderate-credibility evidence that weight-loss interventions were not more effective than exercise only for pain intensity and disability, respectively (4 trials, n = 673; SMD, -0.13; 95% CI: -0.40, 0.14; I2 = 55%; 5 trials, n = 737; SMD, -0.20; 95% CI: -0.41, 0.00; I2 = 32%). Conclusion: Weight-loss interventions may provide small to moderate improvements in pain and disability for OA compared to minimal care. There was limited and inconclusive evidence for weight-loss interventions targeting spinal pain.

Background: Economic evaluations which estimate cost-effectiveness of potential treatments can guide decisions about real-world healthcare services. We performed an economic evaluation of a healthy lifestyle intervention targeting weight loss, physical activity and diet for patients with chronic low back pain, who are overweight or obese. Methods: Eligible patients with chronic low back pain (n¿=¿160) were randomized to an intervention or usual care control group. The intervention included brief advice, a clinical consultation and referral to a 6-month telephone-based healthy lifestyle coaching service. The primary outcome was quality-adjusted life years (QALYs). Secondary outcomes were pain intensity, disability, weight and body mass index. Costs included intervention costs, healthcare utilization costs and work absenteeism costs. An economic analysis was performed from the societal perspective. Results: Mean total costs were lower in the intervention group than the control group (-$614; 95%CI: -3133 to 255). The intervention group had significantly lower healthcare costs (-$292; 95%CI: -872 to -33), medication costs (-$30; 95%CI: -65 to -4) and absenteeism costs (-$1,000; 95%CI: -3573 to -210). For all outcomes, the intervention was on average less expensive and more effective than usual care, and the probability of the intervention being cost-effective compared to usual care was relatively high (i.e., 0.81) at a willingness-to-pay of $0/unit of effect. However, the probability of cost-effectiveness was not as favourable among sensitivity analyses. Conclusions: The healthy lifestyle intervention seems to be cost-effective from the societal perspective. However, variability in the sensitivity analyses indicates caution is needed when interpreting these findings. Significance: This is an economic evaluation of a randomized controlled trial of a healthy lifestyle intervention for chronic low back pain. The findings suggest that a healthy lifestyle intervention may be cost-effective relative to usual care.

Purpose: To assess the causal mechanisms of a healthy lifestyle intervention for patients with chronic low back pain and knee osteoarthritis, who are overweight or obese. Methods: We conducted causal mediation analyses of aggregated data from two randomized controlled trials (RCTs); which included 160 patients with chronic low back pain, and 120 patients with knee osteoarthritis. The intervention consisted of brief advice and referral to a six-month telephone-based healthy lifestyle coaching service. We used causal mediation to estimate the indirect, direct and path-specific effects of hypothesized mediators including: self-reported weight, diet, physical activity, and pain beliefs. Outcomes were pain intensity, disability, and quality of life (QoL). Results: The intervention did not reduce weight, improve diet or physical activity or change pain beliefs, and these mediators were not associated with the outcomes. Sensitivity analyses showed that our estimates were robust to the possible effects of unknown and unmeasured confounding. Conclusions: Our findings show that the intervention did not cause a meaningful change in the hypothesized mediators, and these mediators were not associated with patient-reported outcomes.

Objective: To determine the effectiveness of telephone-based weight loss support in reducing the intensity of knee pain in patients with knee osteoarthritis, who are overweight or obese, compared to usual care. Design: We conducted a parallel randomised controlled trial (RCT), embedded within a cohort multiple RCT of patients on a waiting list for outpatient orthopaedic consultation at a tertiary referral hospital in NSW, Australia. Patients with knee osteoarthritis, classified as overweight or obese [body mass index (BMI) between =27 kg/m2 and <40 kg/m2] were randomly allocated to receive referral to an existing non-disease specific government funded 6-month telephone-based weight management and healthy lifestyle service or usual care. The primary outcome was knee pain intensity measured using an 11-point numerical rating scale (NRS) over 6-month follow-up. A number of secondary outcomes, including self-reported weight were measured. Data analysis was by intention-to-treat according to a pre-published analysis plan. Results: Between May 19 and June 30 2015, 120 patients were randomly assigned to the intervention (59 analysed, one post-randomisation exclusion) or usual care (60 analysed). We found no statistically significant between group differences in pain intensity [area under the curve (AUC), mean difference 5.4, 95%CI: -13.7 to 24.5, P = 0.58] or weight change at 6 months (self-reported; mean difference -0.4, 95%CI: -2.6 to 1.8, P = 0.74). Conclusions: Among patients with knee osteoarthritis who are overweight, telephone-based weight loss support, provided using an existing 6-month weight management and healthy lifestyle service did not reduce knee pain intensity or weight, compared with usual care. Trial registration number: ACTRN12615000490572