Utilization and User Satisfaction with Alternating Pressure Air Cushions

 

Journal

Disability and Rehabilitation: Assistive Technology 

 

Utilization and user satisfaction with alternating pressure air cushions: a pilot study of at-risk individuals with spinal cord injury

Gary A. Wu,Susan L. Garber &Kath M. Bogie

Pages 599-603 | Received 12 Nov 2014, Accepted 05 Mar 2015, Published online: 24 Mar 2015

Pages 599-603 | Received 12 Nov 2014, Accepted 05 Mar 2015, Published online: 24 Mar 2015

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Abstract

Purpose: An appropriate wheelchair cushion is integral to pressure ulcer (PU) prevention for the wheelchair user with SCI. For users who find it difficult to remember or perform weight shifts, an alternating pressure air cushion (APAC) may off-load pressure to minimize PU risk. APACs are considered mobility assistive technology (AT). Effective AT delivery includes consideration of the AT consumer as a unique individual. The Quebec User Evaluation of Satisfaction with Assistive Technology (QUEST) is a structured and standardized method to measure user satisfaction with AT. Method: Twelve full time wheelchair users with SCI were provided with an APAC six times for 2 weeks daily home use every 3 months. At the completion of the 18-month study period, the 8-variable QUEST 2.0b questionnaire was applied to evaluate satisfaction with APAC use. Results: Users were generally quite satisfied with APAC weight (p < 0.01 relative to neutral). Durability was more likely to be an area of concern. Overall, 92% of participants considered themselves quite satisfied or very satisfied with APAC use (p < 0.001). Conclusions: Users with SCI were satisfied with the overall performance of the APAC tested after repeated periods of use. The majority of user’s were very satisfied with APAC comfort overall.

  • Implications for Rehabilitation
  • Abandonment of AT may be reduced if user satisfaction is evaluated.
  • The QUEST 2.0b is a useful and valid measure of user satisfaction with alternating pressure air cushions.
  • In the current study cohort, users with SCI were satisfied with the performance and comfort of the APAC ( Aquila APK2 cushion) tested after repeated periods of use.

Keywords: Comfortdevice performancepressure reliefweight-shiftingwheelchair seating

Introduction

A wheelchair support seating system includes both a seat cushion and back support. The primary purpose of a wheelchair cushion is to redistribute pressure at the seating interface and reduce the risk of pressure ulcers (PUs). In addition, the effective cushion promotes postural stability, increases overall sitting tolerance and enhances functional performance. Numerous studies have shown that although no one cushion can meet every user’s needs, pressure redistribution cushions are a critical component in all wheelchair seating systems in order to maximize function and quality of life for individuals with mobility restrictions [1–5Garber SL, Dyerly LR. Wheelchair cushions for persons with spinal cord injury: an update. Am J Occup Ther 1991;45:550–4
Yuen HK, Garrett D. Comparison of three wheelchair cushions for effectiveness of pressure relief. Am J Occup Ther 2001;55:470–5
Collins F. An essential guide to managing seated patients in the community. Br J Community Nurs 2008;13:S39–40, S42–3, S45–6
Young T. The Flo-tech range of pressure-reducing cushions. Br J Nurs 1997;6:455–6, 458–9
Pellow TR. A comparison of interface pressure readings to wheelchair cushions and positioning: a pilot study. Can J Occup Ther 1999;66:140–9 ]. Wheelchair seating systems should be individualized to each person [6Consortium for Spinal Cord Medicine. Outcomes following traumatic spinal cord injury: clinical practice guidelines for health-care professionals. J Spinal Cord Med 2000;23:289–316[PubMed],, [Google Scholar]]. Consideration must be given to individual and caregiver characteristics, maintenance and affordability [7Remsburg RE, Bennett RG. Pressure-relieving strategies for preventing and treating pressure sores. Clin Geriatr Med 1997;13:513–41[PubMed][Web of Science ®],, [Google Scholar]].

The selection of an appropriate wheelchair cushion is an integral part of any PU prevention program. PUs were the most frequent complication observed during the annual evaluation examination of patients within the Model Systems [8National Spinal Cord Injury Statistical Center, University of Alabama at Birmingham, 2006, Annual Statistical Report, July 2006 [Google Scholar]]. Sacral region PUs were the most frequent (33.3%) followed by ischial (12%) and trochanteric PUs (3%). Historically, individuals with spinal cord injury (SCI) were taught duration and frequency of performing weight shifts to range from 15 to 30 s every 15 to 30 min to 60 s every hour [9Bergstrom N. A research agenda for pressure ulcer prevention. Decubitus 1992;5:22–4, 26, 30[PubMed],, [Google Scholar],10Ho CH, Bogie K. The prevention and treatment of pressure ulcers. Phys Med Rehabil Clin N Am 2007;18:235–53[Crossref][PubMed],, [Google Scholar]]. A retrospective review of the TcPO2 measurements of 46 newly injured and chronic SCI individuals found that the mean duration of pressure relief required to raise tissue oxygen to unloaded levels was 1 min and 51 s, significantly longer than the previously recommended of 15–30 s [11Coggrave MJ, Rose LS. A specialist seating assessment clinic: changing pressure relief practice. Spinal Cord 2003;41:692–5[Crossref][PubMed][Web of Science ®],, [Google Scholar]].

Alternating pressure air cushions (APAC) have not been used extensively in the past due to: (1) added weight, particularly when used on manual wheelchairs, (2) reliance on a power source for activation, (3) the need for battery recharging and (4) cost. New developments in technology have allowed for many of these concerns to be addressed with smaller, lighter-weight components. In general, APACs consist of alternating rows or groups of air cells that cycle by inflating and deflating at a predetermined cadence, typically of 4 to 5 min duration [10Ho CH, Bogie K. The prevention and treatment of pressure ulcers. Phys Med Rehabil Clin N Am 2007;18:235–53[Crossref][PubMed],, [Google Scholar]]. For users who find it difficult either to remember or to perform a weight shift, APACs may off-load pressure to minimize the risk of PUs and facilitate PU healing [6Consortium for Spinal Cord Medicine. Outcomes following traumatic spinal cord injury: clinical practice guidelines for health-care professionals. J Spinal Cord Med 2000;23:289–316[PubMed],, [Google Scholar],12Consortium for Spinal Cord Medicine Clinical Practice Guidelines. Pressure ulcer prevention and treatment following spinal cord injury: a clinical practice guideline for health-care professionals. 2nd ed. Washington, DC: Paralysed Veterans of America; 2014 [Google Scholar]].

Pressure-relieving/redistribution strategies are successful in reducing the risk of PUs when they follow an individualized approach based on individual and caregiver characteristics with the objectives of prevention, early detection and affordability [7Remsburg RE, Bennett RG. Pressure-relieving strategies for preventing and treating pressure sores. Clin Geriatr Med 1997;13:513–41[PubMed][Web of Science ®],, [Google Scholar]]. The biomechanical efficacy of a wheelchair cushion should be evaluated by its pressure-time effect on tissue function [13Rithalia S. Know how – alternating pressure relief. Nurs Times 1997;93:76–7[PubMed],, [Google Scholar]]. However, even the most effective cushion will work only if it is used consistently and according to individual instruction on its operation and maintenance.

APACs are among the devices classified/categorized as mobility assistive technology (AT). The essential components of effective AT delivery models include consideration of the AT consumer as a unique individual, evidence of a specific process for AT delivery and recognition of AT devices and services as complex issues [14Ripat J, Booth A. Characteristics of assistive technology service delivery models: stakeholder perspectives and preferences. Disabil Rehabil 2005;27:1461–70[Taylor & Francis Online][Web of Science ®],, [Google Scholar]]. Utilization of and satisfaction with AT devices can be extremely variable. A number of factors can determine the long-term use of AT including participants’ perceptions of the AT’s characteristics, improved physical function [15Garber SL, Gregorio TL. Upper extremity assistive devices: assessment of use by spinal cord-injured patients with quadriplegia. Am J Occup Ther 1990;44:126–31(Review)[Crossref][PubMed][Web of Science ®],, [Google Scholar]], the presence or absence of anxiety and the individual’s ability to recall AT training [16Wielandt T, Mckenna K, Tooth L, Strong J. Factors that predict the post-discharge use of recommended assistive technology (AT). Disabil Rehabil Assist Technol 2006;1:29–40[Taylor & Francis Online],, [Google Scholar]]. A client-centered approach is essential, in which the person’s perceptions and opinions are addressed along with his/her needs and goals. In the clinical setting, a positive client-therapist rapport is essential in selecting any AT device and can be assessed using The Matching Person to Technology Model [17Scherer M, Jutai J, Fuhrer M, et al. A framework for modelling the selection of assistive technology devices (ATDs). Disabil Rehabil Assist Technol 2007;2:1–8[Taylor & Francis Online],, [Google Scholar],18Adya M, Samant D, Scherer MJ, et al. Assistive/rehabilitation technology, disability, and service delivery models. Cogn Process 2012;13:S75–8[Crossref][PubMed][Web of Science ®],, [Google Scholar]].

Clients, patients and consumers who believed that their personal needs were assessed and that they participated actively in the pre-purchase decision-making process were less likely to abandon devices over time. Matching AT to the consumer also must consider quality of life, mood, support from others, motivation for the AT, program/therapist reliance and self-determination/self-esteem [19Scherer MJ, Sax C, Vanbiervliet A, et al. Predictors of assistive technology use: the importance of personal and psychosocial factors. Disabil Rehabil 2005;27:1321–31. Erratum in: Disabil Rehabil 2005;27:1461[Taylor & Francis Online][Web of Science ®],, [Google Scholar]]. Consumers are more likely to be satisfied with the AT if they feel informed [20Martin JK, Martin LG, Stumbo NJ, Morrill JH. The impact of consumer involvement on satisfaction with and use of assistive technology. Disabil Rehabil Assist Technol 2011;6:225–42[Taylor & Francis Online],, [Google Scholar]]. Negotiation and strategizing are ongoing processes. Satisfaction with mobility technology is associated with the functional and cosmetic features of the mobility device, mobility technology delivery systems/policies, and assessment of the person, technology, and environment. The client’s ability to self-manage these factors either independently or by directing someone to assist is a core consideration.

The Quebec User Evaluation of Satisfaction with Assistive Technology (QUEST) is a structured and standardized method which focuses on user satisfaction with AT [21Demers L, Weiss-Lambrou R, Ska B. Item analysis of the Quebec User Evaluation of Satisfaction with Assistive Technology (QUEST). Assist Technol 2000;12:96–105[Taylor & Francis Online][Web of Science ®],, [Google Scholar]]. Users are asked to indicate the importance of several variables and to rate the associated degree of satisfaction [22Demers L, Weiss-Lambrou R, Ska B. Development of the Quebec User Evaluation of Satisfaction with Assistive Technology (QUEST). Assist Technol 1996;8:3–13[Taylor & Francis Online],, [Google Scholar]]. Across cultures, consumers of AT/devices will express concerns about satisfaction specific to that culture and/or the targeted impairment groups [23Mao HF, Chen WY, Yao G, et al. Cross-cultural adaptation and validation of the Quebec User Evaluation of Satisfaction with Assistive Technology (QUEST 2.0): the development of the Taiwanese version. Clin Rehabil 2010;24:412–21[Crossref][PubMed][Web of Science ®],, [Google Scholar]]. In the current study, the QUEST tool was modified to focus on use of the AT by persons with SCI in a research study, thus variables related to service delivery were not included.

Materials and methods

A repeated measures longitudinal study design of 12 individuals with SCI who were full time wheelchair users was employed. Participants used the cushion for 2 weeks for a total of six trials over an 18-month period. Subject characteristics are summarized in Table 1.

Table 1. Study cohort characteristics.

CSVDisplay Table

Study participants were provided with a commercially available APAC, the Airpulse PK (Figure 1), for repeated periods of 2 weeks daily home use over 18 months of the study protocol. A generic multi-cellular layout of the cushion was used, and a standardized 3-min inflation/deflation cycle was employed. This cycle time was selected to reproduce the duration of independent pressure relief maneuver previously reported to be necessary for tissue oxygenation recovery. Cushion inflation pressure was selected based on user weight, in accordance with the manufacturers’ guidelines.

Figure 1. Airpulse PK cushion.

Display full size

The QUEST 2.0b user satisfaction questionnaire was administered at completion of the 18-month study period, i.e. after six home use trials. The QUEST 2.0b tool had been modified to include eight variables specific to the use of technology in a research study (Table 2). The participant was asked to rate his/her satisfaction with respect to each variable using a 5-point scale. A single sample t test was applied to determine the significance of differences between the observed sample mean and a neutral mean score (3).

Table 2. The QUEST 2.0b tool.

CSVDisplay Table

The Institutional Review Board of the MetroHealth Medical Center, Cleveland, Ohio approved this study. Written informed consent was obtained from all study participants.

Results and discussion

Utilization: AT abandonment

Abandonment of AT, including high- and low-tech devices, seating systems and wheelchairs, is very costly. Over 20 years ago, Phillips and Zhao [24Phillips B, Zhao H. Predictors of assistive technology abandonment. Assist Technol 1993;5:36–45[Taylor & Francis Online],, [Google Scholar]] reported that more than 29% of all devices prescribed to 227 adults with various disabilities were discarded with mobility aids the most frequently abandoned device. They suggested that consumer satisfaction will be enhanced and device abandonment may be reduced if there is more consumer involvement in the device prescription process. In a study of wheelchair utilization and satisfaction following cerebral vascular accident, Garber et al. [25Garber SL, Bunzel R, Monga TN. Wheelchair utilization and satisfaction following cerebral vascular accident. J Rehabil Res Dev 2002;39:521–34[PubMed][Web of Science ®],, [Google Scholar]] found that wheelchair use declined for 31% of the participants, primarily due to reported and assessed improved physical function. However, it was evident that a number of wheelchairs were purchased at great expense that would eventually be discarded. Garber and colleagues suggested that there is a need for re-evaluation of mobility needs during the years following stroke rehabilitation. Most recently, Scherer noted that the steady abandonment rate seen over the past 30 years may be due to challenges within the AT delivery service [26Scherer MJ. From people-centered to person-centered services, and back again. Disabil Rehabil Assist Technol 2014;9:1–2[Taylor & Francis Online],, [Google Scholar]]. There was high continued utilization in the current study, no participants stopped using the APAC in any 2 week home use. Two participants who did not complete the study (and thus did not complete the QUEST 2.0b questionnaire) were lost to follow-up because they moved.

Satisfaction: QUEST 2.0 outcomes

The QUEST 2.0 tool has been shown to be a reliable and valid measure of user satisfaction of individuals with a broad range of assistive devices. However, little data exist demonstrating user satisfaction with AT. Used alone, the QUEST tool cannot directly assess personal factors and potential barriers to use. Shone and colleagues [27Shone SM, Ryan S, Rigby PJ, Jutai JW. Toward a comprehensive evaluation of the impact of electronic aids to daily living: evaluation of consumer satisfaction. Disabil Rehabil 2002;24:115–25[Taylor & Francis Online][Web of Science ®],, [Google Scholar]] found that combining the QUEST with other outcome measures (FIM, demographic data) may provide clinicians who prescribe or recommend these devices with tangible information about utilization and satisfaction. The QUEST has been used in many facilities to measure satisfaction with a wide variety of AT including manual wheelchairs [28Bergström AL, Samuelsson K. Evaluation of manual wheelchairs by individuals with spinal cord injuries. Disabil Rehabil Assist Technol 2006;1:175–82[Taylor & Francis Online],, [Google Scholar],29de Groot S, Post MW, Bongers-Janssen HM, et al. Is manual wheelchair satisfaction related to active lifestyle and participation in people with a spinal cord injury?Spinal Cord 2011;49:560–5[Crossref][PubMed][Web of Science ®],, [Google Scholar]], electronic aids to daily living [26Scherer MJ. From people-centered to person-centered services, and back again. Disabil Rehabil Assist Technol 2014;9:1–2[Taylor & Francis Online],, [Google Scholar]] and computer-related AT [30Burton M, Nieuwenhuijsen ER, Epstein MJ. Computer-related assistive technology: satisfaction and experiences among users with disabilities. Assist Technol 2008;20:99–106; quiz 84–5[Taylor & Francis Online][Web of Science ®],, [Google Scholar]]. In all of these studies, the QUEST was shown to be a useful and valid measure of user satisfaction with the devices.

In the current study as shown in Figure 2, 92% of participants considered themselves quite satisfied or very satisfied overall with use of the APAC (p < 0.001). Looking at the sub-scores for each criterion, one user rated himself not very satisfied with APAC cushion safety. This individual used a manual wheelchair and was concerned that the APAC altered the overall centre of gravity of his seating system, leading to a fear of toppling; however, this did not happen during APAC use. Overall, 58% of users were very satisfied, leading to a statistical significant positive outcome relative to neutral (p < 0.001). Similarly, one user rated himself not very satisfied with APAC cushion comfort; however, overall 67% of users were very satisfied, leading to a statistical significant positive outcome relative to neutral (p < 0.001). Study participants reported using the APAC primarily in their main wheelchair but also in the car for longer trips. User satisfaction with APAC cushion weight was quite satisfied overall, with a statistical significant positive outcome relative to neutral (p < 0.01). Durability was more likely to be an area of concern, with users equally distributed between neutral, quite satisfiedor very satisfied.

 

It is clear from the literature and clinical practice that there is no single cushion that will be effective for every patient. Experienced clinicians who are part of the process of selection must consider user and environment characteristics and user preferences. People already pay out of pocket for APAC use, and this preliminary study indicates that many of the prior reservations are no longer applicable. In addition to evaluating user satisfaction, we evaluated to the impact of repeated APAC use on tissue health. In comprehensive tissue health assessments of the same study participants we have shown that the use of an APAC dynamically and continuously alters interface pressure distribution with sustained positive impacts on tissue health [31Wu GA, Bogie KM. Physiological tissue health responses to conventional weight-shifting and alternating pressure air cushions in at-risk individuals. J Rehabil Res Dev 2014;51:1265–76[Crossref][PubMed][Web of Science ®],, [Google Scholar]]. As Adya et al. state “disability is the gap between a person and his or her environment” [18Adya M, Samant D, Scherer MJ, et al. Assistive/rehabilitation technology, disability, and service delivery models. Cogn Process 2012;13:S75–8[Crossref][PubMed][Web of Science ®],, [Google Scholar]]. Our preliminary studies indicate that APACs provide AT that bridges this gap by positively impacting tissue health [31Wu GA, Bogie KM. Physiological tissue health responses to conventional weight-shifting and alternating pressure air cushions in at-risk individuals. J Rehabil Res Dev 2014;51:1265–76[Crossref][PubMed][Web of Science ®],, [Google Scholar],32Wu GA, Bogie KM. Effects of using a dynamic cushion for the tissue health of persons at-risk. Proceedings of International Society of Biomechanics, Brussels, Belgium, July 2011 [Google Scholar]] and being acceptable to the end users.

APAC availability

Although it has been found that an APAC can positively impact tissue health as much or more than independent pressure relief [30Burton M, Nieuwenhuijsen ER, Epstein MJ. Computer-related assistive technology: satisfaction and experiences among users with disabilities. Assist Technol 2008;20:99–106; quiz 84–5[Taylor & Francis Online][Web of Science ®],, [Google Scholar],33Burns SP, Betz KL. Seating pressures with conventional and dynamic wheelchair cushions in tetraplegia. Arch Phys Med Rehabil 1999;80:566–71[Crossref][PubMed][Web of Science ®],, [Google Scholar]], it can be challenging for wheelchair users to obtain one. The cushion employed in the current study is available directly from the manufacturer or through authorized durable medical equipment dealers. Veterans in the US are able to obtain APACS, including the current generation of this cushion, the APK2, if the company is covered by a Dept of Veteran’s Affairs government contract. APAC may also be obtained under Medicare HCPCS code E2609 for a custom fabricated wheelchair cushion, any size. This code is not a set fee schedule but rather is based on individual consideration. Eligible users must submit a letter of medical necessity with reimbursement paperwork. Non-veterans users who have to pay out of pocket have options to purchase, rent or rent-to-own systems directly from the manufacturer.

Conclusions

The results of this preliminary study indicate that in the study cohort, users with SCI are satisfied with the performance and comfort of the APAC tested (Aquila APK2 Cushion) after repeated periods of use. The cushion used in this study did not raise user concerns with respect to weight or safety for the majority of users, and outcomes were significantly better than neutral. There was some concern with respect to APAC durability. The majority of user’s were very satisfied with APAC comfort overall. We have also shown that APAC use can positively impact tissue health. The current findings on user satisfaction combined with our findings on tissue health lend support for the value of APACs by at-risk individuals with SCI. Further work is needed to determine user satisfaction and the benefits of use, including effects on tissue health, with other APACs and in other populations.

Acknowledgements

The ideas and opinions expressed herein are those of the authors and not necessarily reflective of the NIDRR. The authors would like to thank Drs. Greg Nemunaitis and Melvin Mejia for publicizing the study to their patients and Ms Amy Winslow for participant recruitment and enrolment.

Declaration of interest

The authors declare that there are no conflicts of interest regarding the publication of this paper. This work was funded by the National Institute on Disability and Rehabilitation Research (NIDRR), Rehabilitation Engineering Research Center (RERC) on Spinal Cord Injury, Grant #H133E070024.