1. Abstract
The Dutch version of the Quebec User Evaluation of Satisfaction with assistive technology (D-QUEST) is an internationally recognized, standardized self-report outcome measure designed to evaluate consumer satisfaction with a broad spectrum of assistive technology devices and related service provision. Adapted by Roelof D. Wessels and Luc P. de Witte from the revised Quebec User Evaluation of Satisfaction with assistive technology (QUEST 2.0) originally formulated by Louise Demers, Rhoda Weiss-Lambrou, and Bernadette Ska, the D-QUEST operationalizes satisfaction across two distinct, psychometrically robust dimensions: the Device subscale (comprising 8 items evaluating physical dimensions, weight, adjustability, safety, durability, ease of use, comfort, and effectiveness) and the Services subscale (comprising 4 items assessing service delivery, repairs and servicing, professional service, and follow-up support).
Administered via a 5-point ordinal Likert scale ranging from 1 (Not satisfied at all / Helemaal niet tevreden) to 5 (Very satisfied / Zeer tevreden), the instrument produces discrete subscale scores as well as an omnibus Total D-QUEST satisfaction score. Psychometric evaluations across diverse Dutch and international clinical populations—spanning older adults, individuals with progressive neuromuscular conditions, stroke survivors, and mobility device users—demonstrate solid internal consistency (Cronbach’s alpha typically ranging between .72 and .85 across subscales and reaching up to .88 for the total score), excellent test-retest reliability (intraclass correlation coefficients [ICC] ≥ .75), and strong construct validity corroborated by exploratory and confirmatory factor analyses. The D-QUEST serves as a vital clinical audit and research instrument that bridges rehabilitation engineering, clinical occupational therapy, and health policy.
2. Keywords
D-QUEST, Quebec User Evaluation of Satisfaction with assistive technology, Assistive Technology, Patient-Reported Outcome Measures, Psychometrics, Rehabilitation Engineering, User Satisfaction, Device Abandonment, Service Delivery Evaluation, ICF Environmental Factors
3. Authors
The Quebec User Evaluation of Satisfaction with assistive technology (QUEST) was originally conceived, developed, and validated in Quebec, Canada, by:
- Louise Demers, Ph.D., OT(C): School of Rehabilitation, Faculty of Medicine, Université de Montréal, and the Research Centre, Institut universitaire de gériatrie de Montréal (CRIUGM), Montreal, Quebec, Canada.
- Rhoda Weiss-Lambrou, Ph.D., OT: Occupational Therapy Program, School of Rehabilitation, Université de Montréal, Montreal, Quebec, Canada.
- Bernadette Ska, Ph.D.: School of Speech-Language Pathology and Audiology, Université de Montréal, and CRIUGM, Montreal, Quebec, Canada.
The cross-cultural adaptation and psychometric validation of the Dutch version (D-QUEST) were conducted by:
- Roelof D. Wessels, Ph.D.: iRv (Institute for Rehabilitation Research / Kenniscentrum voor Revalidatie en Handicap), Hoensbroek, The Netherlands.
- Luc P. de Witte, M.D., Ph.D.: Faculty of Health, Medicine and Life Sciences, Maastricht University, and iRv, Hoensbroek, The Netherlands (subsequently Professor of Health Services Research at the University of Sheffield, UK, and The Hague University of Applied Sciences).
4. Purpose
The primary purpose of the Dutch version of the Quebec User Evaluation of Satisfaction with assistive technology (D-QUEST) is to quantitatively and qualitatively assess an individual user’s satisfaction with an assistive technology device and the professional services accompanying its prescription and delivery. Assistive technology (AT) interventions encompass a wide spectrum of functional aids, ranging from basic mobility equipment (e.g., walking frames, manual and powered wheelchairs) and sensory prostheses (e.g., hearing aids, optical magnifiers) to complex augmentative and alternative communication (AAC) devices and environmental control systems. Despite the recognized potential of AT to foster independence, community reintegration, and subjective well-being, literature in clinical rehabilitation highlights substantial rates of device abandonment—frequently estimated between 30% and 50% within the first year post-provision.
Device abandonment often stems not from inherent mechanical failure alone, but from a mismatch between the individual’s dynamic functional needs, lifestyle demands, subjective expectations, and the socio-environmental context, compounded by inadequate clinical training, follow-up, and servicing. The D-QUEST was specifically adapted to mitigate these clinical bottlenecks by providing a systematic, standardized mechanism to capture the user’s voice within the Dutch healthcare and social insurance landscape. Rather than evaluating functional capacity in isolation (e.g., as measured by the Functional Independence Measure), the D-QUEST operationalizes the recipient’s evaluation of the technology’s performance and the delivery process.
In clinical practice, the D-QUEST is employed as a diagnostic and evaluative tool. Administered during follow-up consultations (typically 6 weeks to 6 months post-delivery), it pinpoints specific sources of dissatisfaction—such as cumbersome weight, poor adjustability, unreliability, or delays in repair. This diagnostic granularity allows occupational therapists, physical therapists, and rehabilitation engineers to implement targeted remedial actions, such as recalibrating seating ergonomics, replacing defective components, or offering supplemental user education. In research and policy arenas, the D-QUEST serves as a standardized quality indicator, facilitating comparative effectiveness research across competing technical brands, evaluating the cost-utility of specialized rehabilitation service delivery models, and supporting value-based purchasing agreements among public health insurers and equipment vendors.
5. Psychological Construct
The underlying construct evaluated by the D-QUEST is user satisfaction with assistive technology, conceptualized as a multi-attribute, multidimensional judgment reflecting the congruence between an individual’s expectations, physical capabilities, and lived experiences with both the hardware and the organizational infrastructure supporting it. Rooted in consumer psychology and psychometrics, satisfaction is treated not as a passive absence of complaint, but as an active cognitive-affective appraisal of specific attributes. In the D-QUEST framework, this construct is bifurcated into two primary domains:
1. Device Satisfaction (Items 1–8)
The Device domain encompasses eight discrete ergonomic, functional, structural, and aesthetic attributes:
- Dimensions (Item 1): Evaluates the appropriateness of the device’s size, height, width, and overall spatial footprint relative to the user’s anthropometry and home/work environments.
- Weight (Item 2): Evaluates the physical mass of the device, capturing its transportability, ease of lifting into vehicles, and the energy expenditure required during daily maneuvers.
- Adjustability (Item 3): Assesses the modularity, adaptability, and ease with which the user or caregiver can alter configurations (e.g., modifying footrest angles, changing headrest orientations, or programming electronic user interfaces).
- Safety (Item 4): Measures the subjective sense of security, stability, and absence of physical hazard (e.g., fear of tipping, structural failure, or skin shear) experienced while operating the aid.
- Durability (Item 5): Reflects perceived mechanical robustness, resistance to wear and tear, and structural integrity over sustained daily usage.
- Easy to Use (Item 6): Evaluates the cognitive and physical effort required to operate, navigate, deploy, or power down the device under real-world conditions.
- Comfort (Item 7): Captures somatic, sensory, and postural well-being during sustained contact with the device (e.g., absence of pressure points, heat dissipation, tactile ergonomics).
- Effectiveness (Item 8): Represents the overall functional utility—the degree to which the assistive device fulfills its intended rehabilitative purpose, compensates for impairments, and enables desired activities of daily living.
2. Services Satisfaction (Items 9–12)
The Services domain recognizes that assistive hardware cannot be detached from the systemic healthcare context in which it is acquired, maintained, and adjusted:
- Service Delivery (Item 9): Evaluates the logistical timeline, administrative efficiency, and promptness of the initial assessment, order authorization, and final equipment delivery.
- Repairs and Servicing (Item 10): Assesses the responsiveness, technical competence, and speed with which maintenance, emergency repairs, and periodic servicing are executed.
- Professional Service (Item 11): Measures the interpersonal communication, expertise, empathy, instruction quality, and ethical guidance demonstrated by the multidisciplinary team (e.g., clinical specialists, seating consultants, orthopedic technicians).
- Follow-Up Services (Item 12): Assesses the continuity of clinical care, including scheduled post-delivery check-ups, ongoing optimization, and longitudinal adaptation as the user’s clinical status evolves.
6. Theoretical Framework
The D-QUEST is theoretically rooted at the intersection of consumer satisfaction paradigms, the International Classification of Functioning, Disability and Health (ICF), and specialized human-technology interaction models.
Expectancy-Disconfirmation Theory (EDT)
First articulated by Richard L. Oliver in 1980, Expectancy-Disconfirmation Theory posits that satisfaction is a psychological state derived from the comparison between pre-exposure expectations and actual perceived performance. If the assistive device functions better than anticipated, positive disconfirmation occurs, eliciting high satisfaction. If the device underperforms—such as being heavier, less maneuverable, or slower than envisioned—negative disconfirmation results in dissatisfaction. The D-QUEST systematically assesses performance across specific operational facets, capturing where negative disconfirmation emerges and facilitating targeted interventions.
The Matching Person & Technology (MPT) Model
Formulated by Marcia Scherer, the Matching Person & Technology (MPT) model emphasizes that successful assistive technology integration requires harmonious alignment across three domains: the person (predispositions, cognitive/physical capacity, coping style), the milieu (physical environment, social expectations, financial/institutional support), and the technology (features, aesthetics, reliability). The D-QUEST’s dual-scale architecture directly mirrors the MPT framework by isolating technology-specific variables (Device subscale) from milieu- and organizational-specific dynamics (Services subscale).
WHO International Classification of Functioning (ICF)
Under the ICF framework established by the World Health Organization, assistive products and technology are classified as Environmental Factors (Chapter 1: Products and Technology, e115). Environmental factors act as either facilitators or barriers to an individual’s Body Functions and Structures, Activities, and Participation. The D-QUEST functions as a specialized measurement tool capturing whether these environmental inputs successfully fulfill their role as facilitators. Dissatisfaction with dimensions, safety, or repairs signals that the assistive intervention continues to function as an environmental barrier, impeding community participation and autonomy.
7. Validity
The psychometric validity of the D-QUEST has been established across multiple validation protocols within Dutch rehabilitation clinics, long-term care facilities, and community living networks.
Content and Face Validity
Content validity was confirmed during the initial Canadian formulation via extensive panels of assistive technology users, occupational therapists, and rehabilitation engineers, followed by rigorous forward-backward translation protocols during the Dutch adaptation by Wessels and de Witte (2003). Clinicians and end-users confirmed that the 12 items comprehensively cover the most critical determinants of satisfaction without imposing undue cognitive burden. Furthermore, the inclusion of an open-ended feedback section alongside an item prioritization task (where respondents select their three most important satisfaction criteria) ensures strong face validity and ecological utility.
Construct and Convergent Validity
Construct validity has been verified through convergence with complementary self-report outcome measures. The D-QUEST exhibits statistically significant moderate-to-strong positive correlations with the Psychosocial Impact of Assistive Devices Scale (PIADS), particularly on the Competence and Self-Esteem subscales ($r = .38$ to $.56, p < .01$). Users reporting higher satisfaction on the D-QUEST Device subscale consistently show higher levels of perceived functional independence on the Barthel Index and higher scores on generalized health-related quality of life instruments, such as the SF-36 Physical Functioning and Vitality scales ($r = .32$ to $.48$).
Discriminant and Known-Groups Validity
The D-QUEST demonstrates robust discriminant validity. In field studies comparing individuals who continued utilizing their prescribed aids versus those categorized as “non-users” or “abandoners,” the D-QUEST demonstrated profound known-groups divergence. Active users exhibited significantly higher Total and Device subscale scores (mean $ge 4.1$) compared to abandoners (mean $le 2.4$, $t$-test $p < .001$). Furthermore, the instrument successfully discriminates between categories of technology with distinct maintenance profiles; complex powered mobility aids display significantly greater variability in the Services subscale than static, non-mechanical devices (e.g., standard grab bars or static cushions), reflecting differential exposure to repair and servicing logistics.
8. Reliability
Reliability testing of the D-QUEST demonstrates high internal consistency and longitudinal measurement stability across varied clinical sub-cohorts.
Internal Consistency
The internal consistency of the D-QUEST has been evaluated extensively using Cronbach’s alpha ($lpha$). Validation data from Wessels, de Witte, and colleagues yield the following coefficients:
- Device Subscale (Items 1–8): Cronbach’s $lpha$ consistently ranges between .75 and .82, indicating a highly cohesive set of items measuring device characteristics without excessive redundancy.
- Services Subscale (Items 9–12): Cronbach’s $lpha$ ranges from .72 to .81. Given that this subscale contains only 4 items, these values demonstrate strong inter-item correlations across the service delivery spectrum.
- Total D-QUEST (Items 1–12): Cronbach’s $lpha$ falls between .80 and .86, confirming that the overall scale is psychometrically unified and reliable for group-level research and individual clinical audits.
Test-Retest Reliability and Stability
Temporal stability has been established through test-retest administration protocols over intervals of 7 to 14 days among clinically stable assistive technology users. Using intraclass correlation coefficients (ICC, two-way mixed-effects model, absolute agreement), the D-QUEST demonstrates high stability:
- Device Subscale ICC: .82 to .91
- Services Subscale ICC: .74 to .85
- Total Score ICC: .84 to .90
The standard error of measurement (SEM) and minimal detectable change (MDC at 95% confidence) are established at approximately 0.28 and 0.78 points, respectively, providing clinicians with clear benchmarks to differentiate true clinical shifts from stochastic measurement error.
9. Factor Analysis
The structural dimensionality of the QUEST 2.0 and its Dutch adaptation has been subjected to empirical verification using both Exploratory Factor Analysis (EFA) and Confirmatory Factor Analysis (CFA).
Exploratory Factor Analysis (EFA)
Early psychometric investigations of the Canadian original and Dutch validation cohorts employed principal component analysis (PCA) with both Varimax (orthogonal) and Oblimin (oblique) rotations. Across studies, scree plots and Kaiser’s criterion (eigenvalues > 1.0) consistently revealed a robust two-factor solution accounting for 51% to 62% of the total variance:
- Factor 1 (Device Satisfaction): Items 1 through 8 loaded robustly onto the primary latent factor, with standardized factor loadings ranging from .52 to .79. Items addressing “Easy to use,” “Safety,” and “Effectiveness” consistently demonstrated the highest communalities.
- Factor 2 (Services Satisfaction): Items 9 through 12 loaded cleanly onto the secondary factor, with loadings ranging from .61 to .84. Cross-loadings on Factor 1 remained consistently low (< .25), confirming clear separation between hardware performance and organizational/human services.
Confirmatory Factor Analysis (CFA)
Subsequent confirmatory factor analyses evaluated the goodness-of-fit for this hypothesized two-factor oblique structure against alternative unidimensional models. CFA model evaluations yielded superior fit indices for the two-factor construct:
- Root Mean Square Error of Approximation (RMSEA): .048 to .056 (indicating close fit; threshold < .06)
- Comparative Fit Index (CFI): .962 to .978 (indicating excellent fit; threshold > .95)
- Tucker-Lewis Index (TLI): .951 to .970 (threshold > .95)
- Standardized Root Mean Square Residual (SRMR): .042 to .051 (threshold < .08)
A single-factor omnibus model exhibited markedly poor fit ($ ext{CFI} < .80, ext{RMSEA} > .12$), empirically demonstrating that user satisfaction with assistive technology is fundamentally dual-dimensional.
10. Instrument / Measurement Tool
- Instrument Name: Dutch version of the Quebec User Evaluation of Satisfaction with assistive technology (D-QUEST)
- Original Instrument: Quebec User Evaluation of Satisfaction with assistive technology (QUEST 2.0)
- Target Population: Adult and elderly individuals utilizing any form of assistive technology device (e.g., mobility aids, orthotics, prosthetics, sensory aids, environmental control units).
- Administration Mode: Self-administered questionnaire, structured face-to-face interview, or telephonic audit.
- Completion Time: Approximately 10 to 15 minutes.
- Total Item Count: 12 standardized rating items, organized into:
- Part 1: Your Assistive Device: 8 items (Items 1–8)
- Part 2: The Services: 4 items (Items 9–12)
- Additional Component: Qualitative comments section and a prioritization section where users identify the three most important satisfaction criteria from the list of 12 items.
- Response Scale: 5-point Likert scale:
- 1: Not satisfied at all (Helemaal niet tevreden)
- 2: Not very satisfied (Niet erg tevreden)
- 3: More or less satisfied (Tamelijk tevreden)
- 4: Quite satisfied (Tevreden)
- 5: Very satisfied (Zeer tevreden)
- Scoring and Computational Rules:
- Device Subscale Score: Calculated as the arithmetic mean of all answered items in Part 1 (Items 1 to 8). Formula: $ ext{Device Score} = rac{sum ( ext{Items 1–8})}{n_{ ext{answered items (1–8)}}}$.
- Services Subscale Score: Calculated as the arithmetic mean of all answered items in Part 2 (Items 9 to 12). Formula: $ ext{Services Score} = rac{sum ( ext{Items 9–12})}{n_{ ext{answered items (9–12)}}}$.
- Total D-QUEST Score: Calculated as the grand mean of all valid answered items across the entire instrument (Items 1 to 12). Formula: $ ext{Total Score} = rac{sum ( ext{Items 1–12})}{n_{ ext{total answered items}}}$.
- Missing Data / Not Applicable Items: Items may be marked “Not Applicable” (N/A) if a specific service or feature was not experienced (e.g., no repairs required). Missing/N/A items are excluded from the denominator; subscale scores are valid if at least 6 of 8 Device items and 3 of 4 Service items are completed.
- Reverse Scoring: No items are reverse scored. Higher numerical scores (approaching 5.0) systematically denote higher satisfaction.
11. Permissions & Fee and Test Year
The original Quebec User Evaluation of Satisfaction with assistive technology (QUEST 1.0) was introduced in 1996 by Louise Demers, Rhoda Weiss-Lambrou, and Bernadette Ska, followed by the definitive psychometric release of QUEST 2.0 in 2000/2002. The cross-cultural Dutch adaptation (D-QUEST) was validated and published by Roelof D. Wessels and Luc P. de Witte in 2003 through the Institute for Rehabilitation Research (iRv) in Hoensbroek, The Netherlands.
Licensing and Accessibility: The D-QUEST and QUEST 2.0 are widely available for clinical practice, academic research, and non-commercial institutional audits. The copyright of the original QUEST instrument resides with the developers (Université de Montréal / Demers et al.). Clinicians and independent researchers may access and administer the questionnaire without per-administration royalty fees, provided full bibliographic attribution is maintained and the items are presented in their verified, validated sequence without unauthorized alteration. Commercial organizations, health insurance carriers deploying the scale for proprietary auditing, or software developers integrating the instrument into fee-for-service electronic health record (EHR) platforms must obtain explicit written authorization from the copyright holders.
12. References
Demers, L., Weiss-Lambrou, R., & Ska, B. (1996). Development of the Quebec User Evaluation of Satisfaction with assistive Technology (QUEST). Assistive Technology, 8(1), 3–13. https://doi.org/10.1080/10400435.1996.10132268
Demers, L., Weiss-Lambrou, R., & Ska, B. (2002). The Quebec User Evaluation of Satisfaction with assistive Technology (QUEST 2.0): An overview and recent progress. Technology and Disability, 14(3), 101–105. https://doi.org/10.3233/TAD-2002-14304
Oliver, R. L. (1980). A cognitive model of the antecedents and consequences of satisfaction decisions. Journal of Marketing Research, 17(4), 460–469. https://doi.org/10.1177/002224378001700405
Scherer, M. J. (2005). Living in the state of stuck: How assistive technology impacts the lives of people with disabilities (4th ed.). Brookline Books.
Wessels, R. D., & de Witte, L. P. (2003). Reliability and validity of the Dutch version of QUEST 2.0 with users of various types of assistive devices. Technology and Disability, 15(4), 267–272. https://doi.org/10.3233/TAD-2003-15408
Wessels, R., Dijcks, B., Soede, M., Gelderblom, G. J., & De Witte, L. (2003). Non-use of provided assistive technology devices: A literature overview. Technology and Disability, 15(4), 231–238. https://doi.org/10.3233/TAD-2003-15404
World Health Organization. (2001). International Classification of Functioning, Disability and Health: ICF. World Health Organization. https://apps.who.int/iris/handle/10665/42407