Describing the resource utilisation and costs associated withvertebral fractures: the Build Better Bones with Exercise (B3E) Pilot Trial

This analysis examined costs/resources of 141 women with vertebral fractures, randomised to a home exercise programme or control group. Total, mean costs and the incremental cost-effectiveness ratio (ICER) were calculated. Quality of life was collected. Cost drivers were caregiver time, medications and adverse events (AEs). Results show adding an exercise programme may reduce the risk of AEs.

INTRODUCTION

This exploratory economic analysis examined the health resource utilisation and costs experienced by women with vertebral fractures, and explored the effects of home exercise on those costs.

METHODS

Women ≥ 65 years with one or more X-ray-confirmed vertebral fractures were randomised 1:1 to a 12-month home exercise programme or equal attention control group. Clinical and health system resources were collected during monthly phone calls and daily diaries completed by participants. Intervention costs were included. Unit costs were applied to health system resources. Quality of life (QoL) information was collected via EQ-5D-5L at baseline, 6 and 12 months.

RESULTS

One hundred and forty-one women were randomised. Overall total costs (CAD 2018) were $664,923 (intervention) and $614,033 (control), respectively. The top three cost drivers were caregiver time ($250,269 and $240,811), medications ($151,000 and $122,145) and AEs ($58,807 and $71,981). The mean cost per intervention participant of $9365 ± $9988 was higher compared with the mean cost per control participant of $8772 ± $9718. The mean EQ-5D index score was higher for the intervention participants (0.81 ± 0.11) compared with that of controls (0.79 ± 0.13). The differences in quality-adjusted life year (QALY) (0.02) and mean cost ($593) were used to calculate the ICER of $29,650.

CONCLUSIONS

Women with osteoporosis with a previous fracture experience a number of resources and associated costs that impact their care and quality of life. Caregiver time, medications and AEs are the biggest cost drivers for this population. The next steps would be to expand this feasibility study with more participants, longer-term follow-up and more regional variability.

Build better bones with exercise (B3E pilot trial): results of a feasibility study of a multicenter randomized controlled trial of 12 months of home exercise in older women with vertebral fracture

We pilot-tested a trial of home exercise on individuals with osteoporosis and spine fracture. Our target enrollment was met, though it took longer than expected. Participants stayed in the study and completed the exercise program with no safety concerns. Future trials should expand the inclusion criteria and consider other changes.

PURPOSE

Osteoporotic fragility fractures create a substantial human and economic burden. There have been calls for a large randomized controlled trial examining the effect of exercise on fracture incidence. The B3E pilot trial was designed to evaluate the feasibility of a large trial examining the effects of home exercise on individuals at high risk of fracture.

METHODS

Community-dwelling women ≥ 65 years with radiographically confirmed vertebral compression fractures were recruited at seven sites in Canada and Australia. We randomized participants in a 1:1 ratio to a 12-month home exercise program or equal attention control group, both delivered by a physiotherapist (PT). Participants received six PT home visits in addition to monthly phone calls from the PT and a blinded research assistant. The primary feasibility outcomes of the study were recruitment rate (20 per site in 1 year), retention rate (75% completion), and intervention adherence rate (60% of weeks meeting exercise goals). Secondary outcomes included falls, fractures and adverse events.

RESULTS

One hundred forty-one participants were recruited; an average of 20 per site, though most sites took longer than anticipated. Retention and adherence met the criteria for success: 92% of participants completed the study; average adherence was 66%. The intervention group did not differ significantly in the number of falls (IRR 0.97, 95% CI 0.58 to 1.63) or fragility fractures (OR 1.11, 95% CI 0.60 to 2.05) compared to the control group. There were 18 serious adverse events in the intervention group and 12 in the control group.

CONCLUSION

An RCT of home exercise in women with vertebral fractures is feasible but recruitment was a challenge. Suggestions are made for the conduct of future trials.

Dependencies of the thermal conductivity of individual single-walled carbon nanotubes

This work is aimed at assessing the sensitivity of carbon nanotube (CNT) thermal conductivity to physical and numerical parameters owing to its wide variation in the literature. CNTs of various lengths, chiralities, and temperatures are simulated with molecular dynamics. The Tersoff and AIREBO potentials are also compared in this study. Thermal conductivity is computed with two different non-equilibrium molecular dynamics (NEMD) methods, which show interestingly divergent results; exploring the CNT phonon density of states reveals a proximate cause for the differences.

Spatial resolution of the electrical conductance of ionic fluids using a Green-Kubo method

We present a Green-Kubo method to spatially resolve transport coefficients in compositionally heterogeneous mixtures. We develop the underlying theory based on well-known results from mixture theory, Irving-Kirkwood field estimation, and linear response theory. Then, using standard molecular dynamics techniques, we apply the methodology to representative systems. With a homogeneous salt water system, where the expectation of the distribution of conductivity is clear, we demonstrate the sensitivities of the method to system size, and other physical and algorithmic parameters. Then we present a simple model of an electrochemical double layer where we explore the resolution limit of the method. In this system, we observe significant anisotropy in the wall-normal vs. transverse ionic conductances, as well as near wall effects. Finally, we discuss extensions and applications to more realistic systems such as batteries where detailed understanding of the transport properties in the vicinity of the electrodes is of technological importance.