Introduction

According to the Census Bureau Americans with Disabilities Report, approximately 3.6 million non-institutionalized people greater than 15 years old use wheelchairs [1]. Estimates indicate that there are about 273,000 people with spinal cord injury (SCI) in the US [2]; with an incidence of approximately 12,000 who survive a SCI each year [3]. Seventy percent of them use a manual (MWC) or power wheelchair (PWC) as their primary means of mobility [4]. Wheelchairs (WC) positively impact the level of independence and participation that people with disabilities can achieve [5]. Therefore, WCs problems, such as breakdowns, may negatively impact a user’s life [6] and reduce satisfaction with the WC [7]. Recent studies have shown that WC breakdowns are occurring at a high rate and increasing in the US [8, 9]. A recent study found that 52.6% of those surveyed (n=726) reported at least one WC repair in the prior 6 months [8]. This was an increase from a previous study that found 44.7% of participants (n=2167) required at least one WC repair in the past six months [9]. Negative consequences reported due to a WC breakdown included being stranded, missing medical appointments, being injured, and missing work or school [8, 9]. Of those who indicated at least one repair, between 19.7% [9] and 30.5% [8] indicated at least one adverse consequence. The prevalence of these consequences have been identified to be increasing [8]. Those who use a PWC have been found to have twice as many breakdowns than those who use a MWC [10]. In addition, people who use a PWC with seat functions (e.g. tilt, recline, elevating leg rests) reported being injured in greater numbers than those who did not have seat functions [11]. Although we know that breakdowns are occurring at a high rate, little research has been done to investigate the types of repairs required. This information would help identify the nature of the failures [11] so they can be prevented. The goal of this study was to identify the frequency and types of repairs among MWC and PWC users.

Methods

Participants were enrolled if they were over the age of 16, had neurological impairment due to a non-progressive SCI that occurred at least one year before the study, and used a WC over 40 hours per week. The data were collected between October 2012 and November 2013 at 7 current or former Spinal Cord Injury Model System sites. All centers obtained approval from their local Institutional Review Boards prior to the implementation of study procedures. After obtaining informed consent, participants were asked to complete a survey. All data collected were self-reported by participants.

Demographic variables collected included gender, age, years post injury, and race. WC characteristics and repair variables collected included the type of WC used (MWC or PWC), the number of repairs needed in the past 6 months to the WC used most often, and number and types of repairs done in the past 6 months to the WC used most often. Repairs were categorized into 7 groups: wheels and casters; WC frame; user interfaces; seating system; peripheral items; electrical system; and power and control system. Those who reported needing repairs were asked to indicate if any of the following  adverse consequences occurred due to a WC breakdown: no consequence, been stranded, been injured, missed work or school, and/or missed a medical appointment. Participants were asked to state where the most significant repair was completed.

Data Reduction and Statistical Analysis

Descriptive statistics were performed on gender, age, years post injury, and race. Frequency counts were calculated for repairs needed, type of repairs done, type of adverse consequences, and location where most significant repair was completed stratified by type of WC (MWC or PWC).  Fisher’s exact test was run to evaluate if location where most significant repair was done differ among WC type. SPSS version 21 was used to perform all statistical analyses.

Results

A total of 229 WC users answered the survey. They were between 18 and 78 years old with an average age of 44.7±12.9 and 23.1% were female. They were on average 10.4±8.8 years post injury. Seventy six percent were White, 14.8% African American, 4% reported other race, and 5.2% did not provide race information. One-hundred and forty were MWC users and 89 were PWC users. A total of 131 (57.2%, n=229) of the participants reported that their WC needed repairs in the past 6 months (Table 1). Of those who reported needing at least one repair, ten (7.6%, n=131) reported that none of these repairs were completed, seven (5.3%, n=131)  indicated that repairs were done but the number was unknown, and one person (0.8%, n=131) reported that the question was not applicable. One hundred and thirteen participants recalled type and number of repairs done.

Table 2 summarizes the number of participants who reported having at least one repair done in each category of repairs by type of WC used. Of those who reported needing at least one repair, 30 (22.9%, n=131) reported having at least one adverse consequence due to a wheelchair breakdown. Types and frequencies of adverse consequences are described in Table 3. Table 4 summarizes the location where the most significant repair was done stratified by WC type. Note that 2 participants who stated that repairs where completed did not report where the most significant one was done. More MWC users completed repairs at home themselves or their family members than PWC users, p=0.05.

Discussion

The number of participants completing repairs in the past 6 months remains high, more than 50%, and similar of those in a previous study [8]. These preliminary results can aid to understand what types of repairs are common. Wheel and caster repairs were the most prevalent among MWCs and higher than in PWCs. Fitzgerald’s pilot study showed a similar trend [7]. This could be due to the fact that PWC tires require less maintenance and many use flat-free tires [7]. In addition, research has shown that the vast majority of pneumatic tires users do not maintain the tire pressure recommended by the manufacturer [12]. Repairs in the power and control system were the most prevalent for PWCs. The majority of the repairs (49.2%) that were completed in MWCs were done at home by the MWC users or by a family member. This may indicate that many were not high severity repairs. Additionally, MWC users reported doing repairs themselves more than PWC users.

There are two potential factors that mitigate the number of repairs needed: regular maintenance habits as well as robust/maintenance-free design. To address the first factor, basic maintenance training could empower WC users on how to care for their own WC.  . Several types of repairs needed to wheels and casters could be done by WC users or a caregiver. Because of the complexity of PWCs , it may not be feasible for WC users or caregivers themselves. However, routine inspection to electrical, power, and control systems could help PWC users identify problems before a breakdown occurs. In this way, adverse consequences could be prevented.

The number of WC users reporting at least one adverse consequence due to a wheelchair breakdown continues to be high and consistent with previous literature, 19.7% [9] and 30.5%  [8]. A high percentage (5.3%) of those reporting needing repairs were injured because of a wheelchair breakdown. This percentage of WC users reporting adverse consequences over just six months is concerning and calls for an immediate intervention.  The high prevalence of repairs done in the power and control system of PWCs may indicate the need for more robust/maintenance-free design.

Limitations

This study has several limitations. Data were collected from current and former SCIMS sites, which are centers of excellence, and that could mean the number of repairs were underestimated as compared to the general population. A larger sample size might be needed to be able to detect differences between WC types. Finally, repair was not defined so a repair could have been interpreted differently among participants.