AT can contribute to the achievement of enhanced functioning from an International Classification of Functioning perspective. Efficacy can be assessed by evaluating a variety of variables. Of the 50 reviewed studies, 36 (72%) have investigated this domain. Overall, 26 scales were used to evaluate the functional efficacy. Of these, 6 (23%) instruments were specifically designed and developed for evaluating APs. The most commonly used questionnaire is the WST-Q, which appears to be an outcome measure in 9 studies.

The WST-Q is a standardized evaluation method developed and used to self-evaluate manual or powered wheelchair skills and safety [67]. In addition to assessing capacity (as in Wheelchair Skills Test; WST), the WST-Q assesses confidence and performance (what wheelchair users do and how they do it). In the reviewed articles, it was administered to patients and their informal caregivers [20,21]. With regard to patients, the studies showed that it is an effective way to evaluate variation in 32 power mobility skills (eg, the capability of putting on brakes, propelling a straight distance, and performing a reaching task from their wheelchair) in all power mobility AP users [22]. For example, studies used the WST-Q to evaluate the functional efficacy in patients with autosomal recessive spastic ataxia [23], multiple sclerosis, and SCI [24].

Furthermore, 22% (2/9) of the studies also reported the WST as an instrument to confirm the WST-Q results [25,26]. However, a study showed that the WST can be considered a reliable, valid, and useful tool for evaluating safety and performance domains in several clinical populations who need manual wheelchairs, specifically amputations, stroke, musculoskeletal disorders, SCI, and neuromuscular disorders [27].

The SCI-FI or AT banks allow for assessing an individual’s ability to use new APs and how the ability to execute day-to-day functional activities (with AT) changes over time [28]. It focuses on the ability to perform activities, as usual, using APs, specifically basic mobility (eg, changing or maintaining body positions and transfers), self-care (eg, eating and dressing), fine motor (eg, manipulating and moving objects), ambulation, and wheelchair mobility. Four studies involving large samples (from 269 patients to 1237 patients) of patients with SCI used SCI-FI or AT to assess mobility ADs outcome such as wheelchairs [29,30]. Studies converge in supporting that SCI-FI or AT is an optimal solution to evaluate functioning with AT in 4 domains: basic mobility, self-care, fine motor function, and ambulation [31].

Overall, 3 studies used this self-report measure to quantify “how far and how often they have mobilized with or without assistance” during the last 4 weeks. In detail, this tool investigates power mobility in 5 “Life-Space Levels” (bedroom or sleeping area, external area of the residence, neighborhood, and inside and outside the city). The studies involved patients who required several mobility APs, including mobility service dogs and manual and powered wheelchairs. The reviewed articles showed that this tool can be administered to patients with diseases of the nervous system and sense organs, such as autosomal recessive spastic ataxia [23] or multiple sclerosis [24] and traumatic damage to the spinal cord [26].

Three questionnaires were cited in 2 studies for each to evaluate the functional efficacy of APs in terms of “functional independence,” “functional mobility,” and “functional communication.”

The Functional Independence Measure (FIM) assesses the degree of assistance required by patients to perform motor (eg, eating, grooming, bathing, and dressing) and cognitive (eg, comprehension and expression) activities of daily living [68]. In the reviewed papers, the tool was used to assess the patient’s level of disability as well as a change in patient status consequent to the AT intervention. The FIM has been used to evaluate changes in patients with several motor disabilities, including deficits because of traumatic SCI [29]. The reviewed studies showed that the FIM can be used to evaluate the functional efficacy of 2 main categories of ADs: products for controlling, carrying, moving, and handling objects and devices (ie, smart environment) and products for mobility (ie, wheelchairs) [29,32].

In their study, Tyner et al [29] adopted a modified version of FIM, the Self-Report Functional Measure, an alternative brief self-report instrument developed to measure 13 different motor functions affecting basic activities of daily living in wheelchair users with SCI.

The Functional Mobility Assessment (FMA) was adapted from the Functional Everyday with a Wheelchair (FEW) questionnaire, which included all items relevant to individuals who use mobility devices, that is, wheelchairs, scooters, canes, crutches, or walkers that allow them to perform functional tasks independently, safely, and efficiently as possible [33]. It measures the perceived functional independence of individuals in several tasks, such as “carrying out daily routine” or “personal care tasks.” The 2 reviewed studies applied the FMA as a functional performance efficacy measure applied to mobility APs (eg, wheelchairs, scooters, canes, crutches, and walkers).

FEW is a brief, structured self-report outcome measurement questionnaire used to evaluate the functioning in wheelchair users [69]. Only 1 reviewed study has used this tool to evaluate the performance in the actually lived environment of users who need manual and power mobility devices [34].

The Functional Assessment of Communication Skills for Adults (FACS-A) is a 43-item scale that measures functional communication in daily living activities (eg, understanding television and radio, responding in an emergency, and using a calendar) [70]. In detail, it focuses on 4 domains: social communication; communication of basic needs; reading, writing, and number concepts; and daily planning. In their study, Vincent et al [35] used only items of the first 2 domains that might be affected by using APs with hearing persons. Specifically, FACS-A was used to evaluate changes in communication in hearing persons using “Le communicateur Oralys on pocket PC,” a software that translates sign language into oral French. In another study, FACS-A was adopted to evaluate functional communication in patients with cerebral palsy using augmentative and alternative communication [36].

The other 17 instruments were cited by only 1 article each. Among them, only 2 instruments have been developed for evaluating the AT intervention: the (1) Wheelchair User’s Shoulder Pain Index (WUSPI) [71] and Individually Prioritised Problem Assessment (IPPA) [72,73]. WUSPI was used in a study involving adults with traumatic SCI, which showed the validity of WUSPI as a self-report measure to evaluate the effect of mobility service dogs on shoulder pain in wheelchair users during functional activities (eg, transfers, wheelchair mobility, self-care, and general activities) [26].

The other tools have not been specifically designed and developed for AT interventions. They allow for evaluating several aspects of functional efficacy and have been used according to the prescribed APs. For example, activities that can be performed using ADs can be broken down into several tasks, and assessing difficulty in carrying them out can be an efficacy indicator. In the literature, 3 instruments evaluating this aspect have been found: the (2) IPPA, the (3) COPM [74], and (4) Assessment of Life Habits (LIFE-H) [75]. IPPA is a validated tool that evaluates the perceived effectiveness of an AT intervention. Mortenson et al [37] showed that IPPA can be successfully used with different AT categories and clinical populations. Specifically, in the reviewed article, IPPA was used to evaluate the ability of AT interventions involving APs for personal mobility and domestic activities to improve older AT users’ activity performance. COPM is a client-centered outcome measure for patients to identify and prioritize everyday issues that restrict their participation in everyday life. LIFE-H is a self-report measure to capture the self-rated level of accomplishment for everyday activities of people with disabilities, collecting information on all life habits that people carry out in their environments (home, workplace or school, and neighborhood). One study involved in this review showed that LIFE-H can be used in patients with autosomal recessive spastic ataxia and users of manual and powered wheelchairs [38]. Overall, 6 instruments described in 2 articles were available and were used to evaluate functional efficacy in cognitive abilities. A study has focused on changes in many cognitive domains (eg, orientation, memory, attention, and language) of older adults with or without dementia that uses an electric calendar to compensate for time orientation and memory [39]. The authors investigated changes in cognitive functioning using 2 screening tests: (5) Mini-Mental Examination State [76] and (6) Neurobehavioral Cognitive Status Examination [77]. Moreover, they investigated whether the chosen AP could impact the behaviors in daily living, measured by the short version of the (7) Dementia Behavior Disturbance Scale, a validated tool for behavioral and psychological symptoms in people with dementia [78]. Other studies have focused on specific cognitive domains, particularly language. The (8) Communicative Effectiveness Index modified was used by Londral et al [40] to measure the efficiency of assistive communication devices in supporting speech dysfunction in patients with amyotrophic lateral sclerosis. Another study evaluated the impact of assistive communication products in the language domain, focusing on receptive language skills, reading comprehension, and functional communication [36]. In detail, they evaluated patients with cerebral palsy using the (9) Gray Silent Reading Test for reading comprehension ability [79]; the (10) Test of Auditory Comprehension of Language, revised for comprehension of semantics, morphology, and syntax; and the (11) Peabody Picture Vocabulary Test, revised [80] for receptive (hearing) vocabulary.

Overall, 4 studies have focused on functional autonomy/independence related to AT interventions. First, Mortenson et al [41] assessed mobility independence and performance in activities of daily living in patients who needed mobility APs using 3 subscales of the (12) Functional Autonomy Measurement System [81]. The (13) Barthel Index for Activities of Daily Living was another tool used to measure functional independence in activities of daily living [82]. In the reviewed study, this instrument allowed for investigating changes in functional independence in performing everyday activities (eg, bathing, grooming, dressing, chair transfer, and mobility) in patients with autosomal recessive spastic ataxia who use manual and powered wheelchairs [38]. Similarly, the (14) Spinal Cord Independence Measure III has been used to evaluate any changes in performing activities of daily living and mobility in patients with SCI using manual and powered wheelchairs [42]. Finally, the (15) Occupational Therapy Functional Assessment Compilation (OTFAC) tool [43], which was initially designed as a comprehensive functional assessment tool for occupational therapists, can also be used to isolate the impact of an AT intervention on a person’s functional performance. The reviewed article showed the feasibility of OTFAC as a tool for evaluating changes in functional autonomy in several clinical conditions using mobility APs such as wheelchairs and seating systems [43].

Finally, 2 studies have investigated functional changes in basic and instrumental daily life activities in 2 clinical populations (ie, dementia and amyotrophic lateral sclerosis). First, the (16) Bristol Activity of Daily Living Scale (BADLS) [83], which focuses on independence in performing 20 activities, was developed specifically to be used with patients affected by dementia. The reviewed study used the BADLS to evaluate whether AT interventions extend the time that people with dementia can continue to live independently at home [44]. In addition, the (17) Amyotrophic Lateral Sclerosis Functional Rating Scale is another valid scale to evaluate the patients’ functioning in performing activities of daily living, making use of the prescribed assistive communication devices [40].

In the standard “ISO 9241-11:2018 Ergonomics of human-system interaction—Part 11: Usability,” the definition of satisfaction can also be found: “extent to which the user’s physical, cognitive and emotional responses that result from the use of a system, product or service meet the user’s needs and expectations.”

The high abandonment rates of the AT are associated with the device’s poor performance, which does not meet the environmental needs and does not consider the user’s opinion [22]. The effective use of evidence-based strategies is particularly necessary because the level of availability of AT, especially wheelchairs, is low and can be abandoned if inappropriate for the user. Wheelchair users often have problems such as, for example, discomfort and poor posture. Therefore, it is essential to investigate user satisfaction by involving users in a collaborative target identification process [45]. However, there are only a few wheelchair-specific measures. Overall, 18 articles focused on evaluating patients’ satisfaction with using the prescribed AT devices. A total of 5 instruments were used.

QUEST 2.0 allows for evaluating the individuals’ satisfaction with the AT equipment they are using [84]. The reviewed articles showed that QUEST 2.0 is the most used questionnaire in AT outcome assessment. Papers appear heterogeneous in terms of AT categories and clinical populations. First, QUEST 2.0 can be successfully administered directly to patients to obtain the opinion of those using the APs. In more detail, QUEST 2.0 has been administered to many clinical conditions, including SCI [26], neuromuscular or musculoskeletal disorders (eg, rheumatoid arthritis) [46], and diseases of the nervous system and sense organs (eg, low vision) [35,47]. With regard to the evaluated ADs, QUEST 2.0 was used to evaluate user satisfaction in using 4 different categories of ADs: mobility [26], communication and information management [47,48], domestic activities [46,49], and controlling devices [32].

Assistive Technology Device Predisposition Assessment (ATD-PA) is one of the most well-known instruments for evaluating the overall user experience with AT. Only 1 study used the questionnaire ATD-PA (device form) to evaluate consumers’ subjective satisfaction [50]. This study did not provide detailed information on the ATs or populations that may use it. Therefore, this tool is a stable, valid, and reliable instrument for evaluating products and services, and is potentially usable for all patients who need ATs.

The LIFE-H is a self-report measure of the perceived level of accomplishment for everyday activities of people with disabilities that includes a scale evaluating the individual’s satisfaction regarding the accomplishment of life habits [75]. Moreover, 3 of the reviewed articles showed that this tool can be administered to patients with disabilities affected by diseases of the nervous system and sense organs, such as autosomal recessive spastic ataxia [38]. The studies applied the LIFE-H to 3 main categories of ATs, specifically mobility [37,38], communication and information management [35], and domestic activities [37].

WhOM is the second most commonly used patient-centered measure for evaluating satisfaction with the performance of self-identified activities. Unlike QUEST 2.0 and ATD-PA, it is a specific instrument for wheelchair and seating systems intervention [85]. The reviewed articles showed that this instrument has been used only in patients with 2 broad clinical categories: suspected or confirmed neurodegenerative conditions, such as autosomal recessive spastic ataxia [38], and traumatic damage to the spinal cord [51,52].

The Wheelchair Satisfaction Questionnaire (WSQ) is designed to provide data on wheelchair users’ satisfaction with their AP at a given moment [53]. The only study mentioning this questionnaire supported its potential to give wheelchair users a quantifiable voice on wheelchair function [53]. It is well known that providing data from wheelchair users to wheelchair manufacturers and providers leads to a better design and provision.

The Psychosocial Impact of Assistive Devices Scale (PIADS) scale was developed for evaluating AT devices, asking patients how their life has been affected by using the AT equipment [86]. It is the most used scale for evaluating psychosocial impact; indeed, 9 articles used this instrument, showing that this tool has been administered to several clinical conditions and AT products. First, studies showed that PIADS has been used for a broad spectrum of clinical conditions in need of APs: diseases of the nervous system (eg, spastic cerebral palsy) and sense organs (eg, low vision) [47,54,55], severe motor disabilities [32], and traumatic damage to the spinal cord [26]. With regard to APs, PIADS can be applied to 4 main categories of ADs: mobility (eg, wheelchairs and seating systems) [26,54], communication and information management [47,55], domestic activities [56], and controlling devices [32,57].

Each of the other 3 instruments was cited by only one article to evaluate specific psychosocial impact components from the patient’s perspective: self-esteem, personal well-being, and self-determination. These instruments have been used with specific categories of patients. For example, the Rosenberg Self-Esteem Scale has been used to explore the differences between manual and power wheelchair users regarding self-esteem in persons with SCI [42]. The Arc’s Self-Determination Scale allowed for investigating autonomy, self-regulation, psychological empowerment, and self-realization in young patients with cerebral palsy using argumentative and alternative communication APs for at least 15 years [36]. Finally, Personal Wellbeing Index ensures well-being assessment in community-dwelling people (aged >65 y) who use APs to achieve individual goals for safety and security at home [58].

The WHO defines quality of life as an individual’s perception of their position in life in the context of the culture and value systems in which they live and in relation to their goals, expectations, standards, and concerns. It has a multidimensional nature and can be influenced by several factors and events that occur in a person’s life. To date, 8 reviewed articles have investigated this domain using 6 instruments.

Overall, 3 studies adopted the 36-item Short Form Health Survey (SF-36) to investigate patient-perceived quality of life in participants using APs [88]. SF-36 allows for evaluating 8 domains of quality of life that could be influenced by the prescribed APs: physical functioning, energy or vitality, bodily pain, general health perceptions, limitations owing to physical and emotional problems, social role functioning, and mental health or emotional well-being. The reviewed article is heterogeneous in terms of APs and the clinical population. The APs belong to the mobility category, including wheelchairs and compressive short-sleeve jackets. As clinical populations, these studies involved patients with hereditary pathologies of the connective tissue, specifically Ehlers-Danlos syndrome [60] or SCI [26].

Each of the other 5 instruments was cited by only 1 article to evaluate the quality of life of patients with several clinical conditions and their caregivers. For example, (1) the EuroQoL-5D-5L is an instrument that evaluates the participant’s perception of quality of life, investigating 5 dimensions: mobility, self-care, usual activities, pain or discomfort, and anxiety or depression. One study involving 495 patients with dementia used this tool to evaluate the quality of life in patients with ADs for domestic activities and participation in domestic life and their caregivers [44]. A study by Londral et al [40] described and used 2 questionnaires on quality of life to evaluate the impact of early support with assistive communication devices in patients with amyotrophic lateral sclerosis and their caregivers. First, (2) the McGill Quality of Life Questionnaire is used as a self-reported multidimensional tool to investigate patients’ and their caregivers’ overall quality of life, including physical well-being, psychological symptoms, existential well-being, and support. The other scale, (3) World Health Organization Quality of Life (WHOQOL) brief version [89], is administered only to caregivers to deepen the quality of life in 4 domains: physical and psychological health and well-being, social relations, and environment. This questionnaire has also been used with wheelchair users to investigate how the provision of wheelchairs affects their quality of life domains compared with wait-listed controls [22]. Another tool used with patients who needed assistive communication devices is the (4) Quality-of-Life Profile for People with Physical and Sensory Disabilities (QOLP) [90]. QOLP allows for collecting the perspective and experience (eg, thoughts, feelings, beliefs, attitudes, and resources) of people with disability, particularly young men who have used the assistive communication system for at least 15 years [36]. Finally, the (5) Assessment Quality of Life [91] was used to evaluate 8 dimensions of quality of life (ie, independent living, pain, senses, coping, mental health, happiness, relationships, and self-worth) in community-dwelling people (aged >65 y) who use APs for domestic activities and participation in domestic life [58].

For many people with disabilities, access to ATs has been identified as a facilitator of the full enjoyment of human rights and participation in society and employment [22]. Overall, 7 articles have focused on evaluating the impact of AT interventions on the participation domain. In detail, 5 instruments were used. However, only 2 instruments have been created to evaluate participation using AT, specifically mobility APs: the Nordic Mobility-Related Participation Outcome Evaluation of Assistive Device Intervention (NOMO) [61] and the Assistive Technology Outcomes Profile for Mobility (ATOP-M) [92].

The NOMO instrument evaluates the effectiveness of mobility devices in assessing mobility-related participation [61]. To date, only 1 study has used NOMO as an AT outcome measure involving patients with different self-reported impairments who received a powered mobility device (powered wheelchair and scooter) [61].

The ATOP-M is a self-report measure of the impact of mobility devices on the level of activity and participation of the user [92]. Mortenson et al [59,62] conducted 2 studies involving a wide user base (>100 patients for the study) in which they proposed the ATOP-M as a valid instrument to evaluate the impact of power wheelchairs on the level of participation.

The Late Life Disability Index (LLDI) measures participation frequency and perceived limitation in 16 life tasks [93]. It has been frequently used as an outcome measure in geriatric research. The 3 articles that involve this scale converge in the evaluated APs, that is, powered wheelchairs. On the contrary, the studies disagree on the target. Indeed, 2 studies focused on patients. One study involving 115 end users underlined that the original scale might not be applicable to all power wheelchair users [62]. A following study by Mortenson et al [24] supported the use of LLDI in wheelchair users with multiple sclerosis and SCI. Finally, in the last study, the authors showed that LLDI can be successfully administered to caregivers, collecting the patients’ limitations from the caregivers’ point of view [20].

The Craig Handicap Assessment and Reporting Technique (CHART) scale assesses the degree of social and community participation [94]. It is designed as an interview tool, administered face-to-face or via telephone. Two reviewed studies proposed CHART as a tool for evaluating social participation related to manual and powered wheelchairs [22]. In addition, Hastings et al [42] used this interview with patients with tetraplegia caused by SCI.

Among the reviewed tools, 17 scales were designed to evaluate the ADs, including the QUEST 2.0, ATD-PA, WhOM, WSQ, ATOM, WheelCon-P, PIADS, IPPA, WST, SCI-FI or AT, FEW, FMA, WST-Q, WUSPI, NOMO 1.0, ATOP-M, and CATOM. These tools allowed the assessment of 7 domains, satisfaction (4/17, 24%), usability (1/17, 6%), confidence (1/17, 6%), psychosocial impact (1/17, 6%), functional efficacy (7/17, 41%), participation (2/17, 12%), and caregiver burden (1/17, 6%).

Approximately half (23/50, 46%) of the reviewed studies described outcome measures applied to several APs in a single category. In contrast, only 2 studies used the same instruments for assessing AT products of multiple AT categories (ie, mobility and domestic activities). Interestingly, these studies involved only the caregivers of AT users (eg, CATOM or IPPA).

Overall, 74% (39/53) of the studies involved small samples of ≤100 patients or caregivers, of which 18% (7/39) involved ≤10 patients (2 case studies). Most studies (44/50, 88%) involved patients with different clinical conditions; 4 articles recruited caregivers, and the other 2 included both categories. Most studies did not report the specific pathological conditions of the sample, including “AT users.” Among the reported clinical conditions, most studies involved patients with SCI (n=8), followed by neuromuscular or musculoskeletal disorders and diseases of the nervous system and sense organs (eg, amyotrophic lateral sclerosis, dementia, stroke, multiple sclerosis, low vision, and autosomal recessive spastic ataxia).

Most instruments were self-report questionnaires completed by the participants involved in the study. Only 8 studies reported objective outcome measure instruments administered by clinicians. Of these, 4 (50%) also reported self-reported measures. With regard to administration time, only 6 studies reported this information.