The relationship between in-seat movement and pressure ulcers in wheelchair users with SCI/D

Abstract

Objective

To identify parameters that are associated with time at pressure, are most related to pressure ulcer outcomes, and that may be used to influence pressure ulcer (PrU) outcomes in future intervention studies.

Design

Analysis used datasets from cross-sectional and longitudinal observational studies. Wheelchair-usage and in-seat metrics thresholds were optimized to differentiate individuals in PrU or No PrU groups. Logistic regression identified the demographics and in-seat activity metrics that impacted PrU outcomes.

Setting

General Community.

Participants

Fifty individuals with spinal cord injuries and/or disorders (SCI/D) who use a wheelchair as their primary mobility device. 22 subjects were within the first year following injury and 28 had been using a wheelchair for over 2 years. Twenty-one participants reported PrU outcomes.

Interventions

Not applicable.

Outcome Measures

Time in chair, pressure relief frequency, weight shift frequency, percentage of seated time that the subject is active (CoP Percent Active), frequency of in-seat movement, unloading event frequency, maximum time between events, and number of transfers.

Results

Optimal cutoff thresholds for the most significant in-seat movement metrics included: unloading event frequency of 3.1 times per hour (OR 0.353, 95% CI [0.110, 1.137]), maximum time between events of 155.4 min (OR 2.888, 95% CI [0.886, 9.413]), and CoP Percent Active of 2.6% (OR 0.221, 95% CI [0.063, 0.767]). When individuals were more active than these cutoffs, significantly more individuals were in the no pressure ulcer group. In predictive modeling, CoP Percent Active was the in-seat movement metric that significantly predicted PrU outcomes. The model was improved by adding age, occupation, and injury completeness.

Conclusion

Of the 4 significant predictors in the model, only CoP Percent Active was modifiable. Therefore, an opportunity exists to design approaches to modify behavior. However, the results illustrate that the key to preventative movement may be through functional movement as opposed to scheduled, routine pressure reliefs.

Keywords:

• Wheelchair
• Movement
• Pressure ulcer
• Risk assessment
• Behavior

Acknowledgements

The authors thank the staff members at Duke University and the Durham Department of Veterans Affairs Medical Center, the Kessler Foundation’s Spinal Cord Injury Laboratory, and the Shepherd Center’s Virginia C. Crawford Research Institute for assistance in collecting data.

Disclaimer statements

Contributors None.

Funding Research reported in this publication was supported by the National Institute on Disability, Independent Living, and Rehabilitation Research [grant number H133E080003] and United States Department of Defense [grant number W81XWH-13-1-0387]. Research reported in this publication was also supported by the National Institute on Aging of the National Institutes of Health under Award Number R01AG056255. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Conflicts of interest Authors have no conflict of interests to declare.