Relationship Between Health Related Quality of Life and Quality of Wheelchair Provided to Veterans

Sandra Hubbard, MA, OTR/L, ATP, Shirley Fitzgerald, PhD, Dean Reker, PhD, RN, Lewis Kazis, ScD,
and Fred Downs, MBA
Human Engineering Research Laboratories –
University of Pittsburgh –
VA Pittsburgh Healthcare System
Pittsburgh, PA 15206

ABSTRACT

There is compelling evidence that mobility, access to the community, and social integration enhance health related quality of life. Wheelchair quality and design can either maximize or limit a user's potential to participate in society, thus should also have an effect on quality of life. Using a retrospective study design, three years (FY 1999, 2000, 2001) of data from two VHA databases were merged to determine whether veterans provided with “better” quality wheelchairs would have significantly more ability to fulfill their physical and emotional life roles and function in society than veterans prescribed “lower” quality wheelchairs. Results indicate that individuals with better HRQoL were more likely to receive better quality wheelchairs.

KEYWORDS

Assistive technology, outcomes, mobility, participation

BACKGROUND

There is compelling evidence that mobility, access to the community, and social integration enhance health related quality of life (HRQoL) [1-4] . In fact, social participation is a more important predictor of HRQoL than physical functioning or extent of injury [5, 6] . If wheelchair quality and design maximize the user's potential [7] , then perhaps wheelchair quality will have an effect on HRQoL, by providing more opportunities for access to the community and social integration gains for wheelchair users.

The key attributes of a “quality” manual wheelchair are reduced weight and the option to adjust critical physical dimensions to provide a functional, personal fit. Combined, these factors provide the manual chair consumer with improved comfort, ease of transfers, and propulsion efficiency. In power chairs, quality translates into reduced attendant dependence, less probability of collisions, lower risk of breakdown and faster overall transit speeds. Thus, wheelchair quality and design may directly impact the user's ability to participate in society.

RESEARCH QUESTION

The purpose of this study was to determine whether individuals who are provided with “better” quality wheelchairs will have significantly more ability to fulfill their physical and emotional life roles and social function in society than individuals who have been provided with “lower” quality wheelchairs.

METHOD

Design :

Using a retrospective study design, three years (FY 1999, 2000, 2001) of data from two Veterans Health Administration (VHA) databases, the National Prosthetic Patient Database (NPPD) and the Veteran Health Study (VHS), were merged to create a dataset of veterans who both received a wheelchair and completed the SF-36V. There were 11130, 15772, and 15787 records for FY99, FY00, and FY01 respectively. The National Prosthetics Patient Database (NPPD) contains detailed information on the procurement, costs, and delivery of rehabilitation technology for veterans by tracking every device issued to veterans. The SF-36V was adapted from the MOS SF-36 (Kazis, 2000; Kazis et al., 1999); 1.4 million V/SF-36 questionnaires were administered nationally on a cross-sectional basis, representing 40% of the VA enrollee population (3.4 million). Data collection took place between July 1999 and January 2000.

Operational Definitions :

Physical and emotional life roles and social function in society were measured by the Role Limitation Due to Physical Health Problems (RP; scale = -6.75 to 111.45), Role Limitation Due to Emotional Problems (RE; scale = -16.95 to 115.35), and Social Functioning (SF; scale = 0 to 100) SF-36V scales, and the health behavior questions “Compared to one year ago, how would you rate your physical health in general now?” (CP; scale = 1 to 5), “Compared to one year ago, how would you rate your emotional problems in general now?” (CE; scale = 1 to 5), and “Do you live alone?” (SS; scale = 1 to 5). A higher score on the RP, RE, and SF scales indicates better health. A lower score on the CP and CE scales indicates more change for the better.

Quality of wheelchair was determined from “Health Care Common Procedure Coding System (HCPCS) codes”, developed by the Center for Medicare and Medicaid (CMS) for reimbursement purposes. “Better” quality wheelchairs included chairs that could be individualized: ultra-light (i.e. K0005) and adjustable power wheelchair chairs (i.e. K0014). “Lower” quality wheelchairs included the standard wheelchair with minimal adjustments (i.e. K0001, 0002, 0003).

Possible confounding variables included number of co-morbidities (numco), age, sex, and race. Three samples were created based on when the participant received their wheelchair in relation to completing the SF-36V. Sample 1 (N=6304 for FY99) received their wheelchair during FY99 then completed the SF-36V. Sample 2 (N=2620 for FY99) also received their wheelchair in FY99, but completed their SF-36V at least 90 days after receiving their wheelchair, therefore had time to adjust to their chair and reflect these adjustments in their SF36V scores. Sample 3 (N=2069 for FY99, 15586 for FY00, and 15720 for FY01) completed the SF-36V then received their wheelchair. Veterans were then assigned to a group based on whether they received a “better” or “lower” quality wheelchair.

Analyses :

A univariate analysis found no systematic bias when taking into considering the large sample size. Because a time trend was noted in the univariate analysis, a multivariate regression was performed with time and quality of wheelchair as the main effects and RP, RE, SF, TR2, and TR3 as the outcome variables.

RESULTS

Univariate results indicated that veterans who receive better quality wheelchairs reported better HRQoL than veterans who reported “lower” HRQoL. However, the HRQoL of veterans who had not yet received their wheelchair, but would later receive a “better” quality wheelchair, was higher than veterans who had already received a “better” quality chair, indicating veterans with a higher HRQoL receive “better” quality wheelchairs. See Table 1.

**Table 1 Frequency, mean, and standard deviation of “better” and “lower” quality groups**
		Sample 1+2			Sample 3
		better	lower		better	lower
Means (Standard Deviation)	mean(sd) n	mean(sd) n	p	mean(sd) n	mean(sd) n	p
RP	5.47(27.13) 305	3.53(24.80) 7011	0.826	7.53(29.43) 73	3.58(25.78) 1714	0.262
RE	29.77(46.02) 299	23.19(42.57) 6834	0.687	32.39(48.28) 69	23.44(43.12) 1677	0.093
SF	33.97(29.09) 313	29.67(27.53) 7185	0.839	35.00(33.00) 75	29.50(27.62) 1764	0.159
CP	3.77(1.06) 312	3.97(1.05) 7138	0.015	3.84(0.93) 75	4.04(0.97) 1757	0.086
CE	3.45(0.97) 308	3.55(1.02) 7148	0.969	3.52(1.05) 73	3.55(0.95) 1752	0.805
SS	22% 343	16% 8590	0.005	17% 84	17% 1985	0.941
numco	4.98(3.65) 343	6.18(3.54) 8590	<.0001	4.49(3.33) 82	5.85(3.46) 1955	0.000
age	61.44(13.33) 343	67.70(12.28) 8590	0.721	59.04(13.17) 82	67.99(11.64) 1955	<.0001
sex	96% 342	96% 8570	0.970	96% 84	96% 1976	0.916
race	66% 343	63% 8590	0.262	71% 84	72% 1985	0.879
RP = Role Physical RE = Role Emotional SF = Social Functioning CP = Change Physical CE = Change Emotional SS = % of veterans who live alone numco = Number of cormorbidities age = Age as of Feb 1999 sex = % of male veterans race = % of veterans who are white vs. not white Continuous variables reported as means(std dev) Discrete variables reported as frequency

DISCUSSION

Veterans who are younger, more active, more physically and emotionally healthy, and have fewer co-morbidities tend to receive “better” quality wheelchairs. This is perhaps because these veterans are more socially savvy. There could also be an element of clinician bias. A study to determine if this pattern holds true across diagnoses is underway.

A time factor emerged. Veterans who had their wheelchairs for more than 90 days tended to report a higher HRQoL than those who had their chairs for less than 90 days. However, only the CP scale was significant (p <.0001) indicating that veterans who had their chairs longer experienced more change for the better in their physical health. P-values for SF and CE were equal to 0.065 and 0.072 respectively, indicating a trend toward better social functioning and more change for the better in emotional health. This time effect was not apparent for “lower” quality wheelchairs.

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ACKNOWLEDGEMENTS

This study was partially funded by the VA Center for Health Equity Research and Promotion (CHERP), and a VA Rehabilitation Research and Development Pre-Doctoral Fellowship Award.

Author Contact Information:

Sandra Hubbard, MA, OTR/L, ATP, PhD Candidate,
Human Engineering Research Laboratories - 151R1,
7180 Highland Drive,
Pittsburgh, PA 15206 (412) 365-4850
EMAIL: slh78@pitt.edu