Understanding Stakeholder Attitudes, Needs and Trends in Accessible Tourism: A Systematic Review of Qualitative Studies

: The inclusion of people with disabilities (PwD) in tourism is a phenomenon that encompasses various inﬂuencing factors, such as accessibility, which must be reviewed for this process to work correctly. Accessible tourism has advantages for both people with disabilities and everyone else. It provides an opportunity for everyone to enjoy leisure without barriers. However, there are still factors that limit the proper operation of the sector, which require a review and new strategies for its improvement. The objective of this review is to o ﬀ er a synthesis of those challenges that must be addressed in order to achieve quality accessible tourism, as well as to present the various emerging trends that can represent an important advance for the future of accessible tourism. To this end, a qualitative study review process has been carried out where the di ﬀ erent opinions and perceptions of the various actors involved in the accessible tourism sector are considered. A thematic analysis and synthesis of the information was conducted using the “Thematic Synthesis” procedure. The methodological quality of the studies included in the synthesis was also assessed. The studies reviewed show a need to recognize disabled travelers as autonomous and independent people who seek to escape from their daily routine, and who require certain speciﬁc supports to facilitate their tourist experience. Accessible tourism is valued as a good market opportunity, but its proper development requires greater sta ﬀ awareness to promote co-creation in tourism, as well as the support of technological systems to create individualized tourist proﬁles detailing the needs of each person.


Introduction
According to the World Health Organization (WHO), more than a billion people worldwide-equivalent to approximately 15% of the world's population-have some form of disability. Levels of disability are rising worldwide due to the gradual aging of the population and to an increase in chronic health conditions, among other factors [1]. The World Tourism Organization (UNWTO) notes that the accessibility to spaces, products and services related to tourism must be a central component of any policy defined as responsible and sustainable [2].
The total volume of the accessible tourism market, made up of people with disabilities (PwD) and People with Reduced Mobility (PRM) in the European Union, easily exceeds 120 million tourists. If the group of tourists over 65 years of age is added to this group, it totals almost 127.5 million people [3,4]. To these figures can be added the total data from other parts of the world. According to experience. In this sense, the support of new technologies to facilitate the range of services in a more concrete and specialized way, and collaboration in co-creating tourist spaces, products, and experiences, is regarded as vitally important [22,33].
To meet these particular requirements in relation to the type and severity of the disability, customization offers a valuable strategy, as it allows users to establish their specific requirements and needs, steering them toward products and services that are relevant to them [34]. Offering high quality tourist experiences to PwD continues to be a great challenge, and not only because of architectural or relational barriers. In many cases, the main problem results from a lack of coordination between the different actors involved in co-creating tourist experiences. In this regard, digital ecosystems can make tourism environments more accessible by enabling value co-creation [35]. Moreover, co-creation is also related to an increase in customer satisfaction, customer loyalty, and spending on services [36].
A large body of scientific literature has been based on analyzing perceptions of the PwD services provided by accommodation managers [24]. However, all the stakeholders need to be considered. The opinion of PwD on the accessibility conditions at tourist destinations is of vital importance [37,38]. Therefore, control and coordination, communication, clarity of roles and responsibilities, collaboration, and integration between professionals and PwD make up a key framework [39].
On the motivations of PwD for traveling, the results in the existing literature offer a wide range of stimuli and incentives that influence their decision. These include the possibility of escaping from the daily routine, relaxation, or enjoyment [40]. It seems that although tourists with disabilities have a high level of intrinsic motivation, they travel mainly for extrinsic reasons. Perceived accessibility has a significant impact on all types of motivations [32].
The current problem is that even though the potential of accessible tourism has been partially recognized at the market level, it can be said that the accessibility market remains precarious in different parts of the world, and that tour operators require more training and a more sophisticated understanding of what accessible destination experiences mean [41,42]. In addition, there is also a need to conduct a detailed analysis to identify what elements make a destination worthy of being considered competitive for the accessibility tourism market [43,44].
There are pull factors for a destination that can only be determined through qualitative research. These factors can be specific motives, cognitive, and affective images, which can also provide implications for the use of thematic and content analysis, destination management, marketing, and tourism experiences [45]. All of this must be applied to the tourism industry to enhance the products and services offered, in an effort to address the most neglected and most important dimension, which is closely related to tourist behavior [46]. This can be useful for the business world when designing tourism marketing strategies, since ascertaining the behavior of tourists is an essential tool for decision-making and a starting point for strategic planning [3].
Therefore, the objective of this systematic review is twofold. It is intended to, on the one hand show those challenges that accessible tourism must overcome in order to improve its outlook, and, on the other, provide an insight into those trends and practices that may be useful to ensure quality accessible tourism to anyone. Based on the selected methodological perspective of analysis and synthesis of qualitative evidence, and on the perceptions and visions of the different agents involved in developing accessible and inclusive tourism, we intend to showcase the new global perspectives that will have to be taken into account when developing a future agenda that improves the quality and experiences of accessible tourism, as has been requested in previous research [47,48].

Getting to Know the Disabled Traveler
The literature related to tourism and disability often highlights the frequent exclusion suffered by PwDs, and at the same time emphasizes the benefits that tourism brings in the fight against this exclusion [49]. It does, however, overlook one fundamental aspect, which is determining the Sustainability 2020, 12, 10507 4 of 23 peculiarities and diversities of travelers with disabilities [50,51]. Advances in tourism research must establish strategies that make it possible to better understand the needs and peculiarities of travelers with disabilities so as to establish more innovative, socially responsible, and sustainable management strategies [52]. All these actions seem unimaginable without taking into account the contributions of inclusive tourism, which helps us to think in a more constructive and critical way about the different ways of approaching tourism with the aim of increasing benefits and obtaining more equitable and sustainable results. Inclusive tourism not only aims to be a tool to expand access to consumption or production in tourist sites, but it also seeks to create new environments that are more suitable to experience and interaction [53]. Achieving tourism inclusion and full access to travel opportunities requires great knowledge, effort, and commitment on the part of tourism providers [54]. Tourism agents must bear in mind that the motivation factor is one of the most important elements for people with disabilities when choosing a tourist destination [51].

Accessibility for Tourism Inclusion
Accessibility and equal opportunities are becoming increasingly important in today's societies [55]. However, advocates have noted that to take the next step, we must analyze how accessible tourism relates to the paradigm of sustainable development. In this sense, this relationship goes beyond issues related to access, and require adopting an inclusive perspective [56]. Inclusive tourism affects competitiveness by making destinations more accessible, and thus being able to receive anyone. This development hinges on providing an urgent and positive response to the challenge of inclusion and accessibility by adapting policies so that destinations are available to all [57].
The advances observed in customer participation, their influence on the modification and creation of tourist destinations, and technological advances have all contributed to innovation in co-creation processes. In this regard, it is necessary to develop a deeper understanding of how the new information and communication technologies can serve as mediators in the innovation processes for co-creation between clients and tourism providers [58], and more specifically among clients with disabilities [59].

Accessible Tourism as an Emerging Market Bet
Tourism can be defined as a key activity from the perspective of economic and social development. Leading tourism in the future will depend to a large extent on the way in which destinations declare themselves to be innovative, inclusive, and competitive [60]. However, despite being a booming economic sector, efforts are still required to identify groups of consumers and potential clients, to ascertain the different profiles of clients with disabilities, and characterize their attitude regarding the product, which will ultimately have repercussions on greater tourist satisfaction [61]. The case studies, focused on specific geographic areas, have been useful in analyzing the state of implementing accessible tourism in different countries, as well as in narrowing many of the problems and difficulties faced by people with disabilities when traveling [62].
The future agenda of the accessible tourism market must take into account different influencing factors if it is to achieve adequate progress. Some of the advances required are as follows: the need to provide sources of accessible information that increase the participation of PwD in the various tourist activities [63], review of compliance with policies and regulations that determine how well PwD can access online tourist information [64], and identify ways of using new and emerging technologies that allow for enhancing value co-creation by providing the opinion of tourists with disabilities on accessibility to different tourist environments [65].
In recent studies, the emerging market that accessible tourism represents has become clear. Even for small tourism markets, such as rural tourism, results have shown the positive effect that tourism activities have on the economic performance and demographic resilience in rural areas characterized by high accessibility [66].

Review of the Design Protocol
We conducted a systematic peer review of the accessible tourism literature, to include an analysis and synthesis of qualitative research in the field. Methodologically, the systematic review was carried out by summarizing and analyzing the evidence and quality of the information in a structured, explicit, and systematic way [67,68]. This summary was prepared and written in keeping with the methodological suggestions in Enhancing transparency in reporting the synthesis of qualitative research: ENTREQ [69], and Preferred Reporting Items for Systematic Reviews and Meta-Analyses: The PRISMA Statement [70]. Finally, special attention was also given to following the recommendations presented in Chapter 20-Qualitative Research and Cochrane, of the Cochrane Handbook for Systematic Reviews of Interventions [71] and in Chapter 2-Systematic reviews of qualitative evidence, of the JBI Manual for Evidence Synthesis [72].

Search Strategy
The search involved a systematic review of papers on subjects related to the areas of Social and Legal Sciences and Health Sciences published in Web of Science, Scopus, MEDILE PubMed, and ProQuest (APA PsycInfo). The search was carried out between the months of May and June 2020, using search strings obtained with components created in accordance with the Medical Headings and Subjects of Medline and the EBSCOhost, as well as with the main terms used in published papers. These were: (1) accessible tourism or adapted tourism, (2) people with disability or disabled persons, (3) hotel managers or tourism experts, (4) perceptions or feelings or views, (5) tourism economy or tourism market industry, and (6) quality of accessible tourism. The specific labels of each database were used, as were the Boolean AND/OR operators. All of these concepts were selected based on the objectives of the study and the recommendations of experts in the area. Finally, no filters or restrictions were specified involving the date of publication, location, ages of the samples, or method of accessing the documents. Table 1 summarizes the bibliographic search strategies used in each database.

Selection of Studies
The studies were reviewed independently by two individuals  articles, screening by title and abstract, screening after reading the full text (application of inclusion-exclusion criteria). The reviewers used a series of eligibility criteria for the studies that would be part of the review (Figure 1). Sustainability 2020, 12, x FOR PEER REVIEW 6 of 24 of duplicate articles, screening by title and abstract, screening after reading the full text (application of inclusion-exclusion criteria). The reviewers used a series of eligibility criteria for the studies that would be part of the review (Figure 1).

Data Extraction
The data from the studies included in the review were extracted simultaneously but independently by two different researchers (A.J.R.-C. and Y.M.D.L.F.-R.). In keeping with Chapter 2-Systematic reviews of qualitative evidence, of the JBI Manual for Evidence Synthesis [73], specifically the Data Extraction Section, the following fields were located in the included studies: Author and year, Methods for data collection and analysis, Country, Phenomena of interest, Setting/Context/Culture, Participant Characteristics and Sample Size, Description of Main Findings (see Appendix A). As part of a preliminary step, the data were extracted and managed in piloted and adapted electronic files before all the selected studies were jointly evaluated. Finally, a third author (A.M.-F.) with methodological experience validated the process and, with his participation, the discrepancies were resolved by consensus.

Analysis of the Content
In order to analyze the qualitative studies that were eventually included in the synthesis, we performed a thematic analysis using the "Thematic Synthesis" process, the goal being to identify the main topics and subtopics associated with research in the field of accessible tourism and disability, and to summarize the information reported in the studies. Quoting Thomas and Harden [67], "The synthesis took the form of three stages which overlapped to some degree: the free line-by-line coding of the findings of primary studies; the organisation of these 'free codes' into related areas to construct 'descriptive' themes; and the development of 'analytical themes'" (p. 4). Each of these stages was carried out through the collaborative work of academic peers with the help of the EPPI-Reviewer 4 software, which is used to create all kinds of reviews of the literature, including systematic reviews, metaanalyses, "narrative" reviews and meta-ethnographies. This software generates templates where all the information from the results of the qualitative studies included is stored, arranged, and grouped.

Data Extraction
The data from the studies included in the review were extracted simultaneously but independently by two different researchers (A.J.R.-C. and Y.M.D.L.F.-R.). In keeping with Chapter 2-Systematic reviews of qualitative evidence, of the JBI Manual for Evidence Synthesis [73], specifically the Data Extraction Section, the following fields were located in the included studies: Author and year, Methods for data collection and analysis, Country, Phenomena of interest, Setting/Context/Culture, Participant Characteristics and Sample Size, Description of Main Findings (see Appendix A). As part of a preliminary step, the data were extracted and managed in piloted and adapted electronic files before all the selected studies were jointly evaluated. Finally, a third author (A.M.-F.) with methodological experience validated the process and, with his participation, the discrepancies were resolved by consensus.

Analysis of the Content
In order to analyze the qualitative studies that were eventually included in the synthesis, we performed a thematic analysis using the "Thematic Synthesis" process, the goal being to identify the main topics and subtopics associated with research in the field of accessible tourism and disability, and to summarize the information reported in the studies. Quoting Thomas and Harden [67], "The synthesis took the form of three stages which overlapped to some degree: the free line-by-line coding of the findings of primary studies; the organisation of these 'free codes' into related areas to construct 'descriptive' themes; and the development of 'analytical themes'" (p. 4). Each of these stages was carried out through the collaborative work of academic peers with the help of the EPPI-Reviewer 4 software, which is used to create all kinds of reviews of the literature, including systematic reviews, meta-analyses, "narrative" reviews and meta-ethnographies. This software generates templates where all the information from the results of the qualitative studies included is stored, arranged, and grouped.
From there, the authors can extract the results to respond in a massive way to the research questions or objectives proposed, which at the same time remain related to the "Analytical Themes" [74].

Analysis of the Methodological Quality of the Studies
Two authors (M.D.M.-D. and A.J.R.-C.) proceeded with the methodological quality assessment of the qualitative studies that would ultimately form part of the synthesis. The quality assessment process was reviewed by a third expert author (Y.M.D.L.F.-R.). Potential discrepancies were found by consensus among the authors. The Critical Appraisal Skills Programme (CASP), "Qualitative Studies Checklist" [75] was used to assess the methodological quality of the included studies. The checklist is structured into a total of 10 questions that assess the methodological quality of qualitative studies. The first two questions involve the screening. Once they are answered, they prompt reflection on whether the study warrants further evaluation. The items are subgrouped under three questions: Are the results of the study valid? (Section A); What are the results? (Section B); Will the results help locally? (Section C). For each item, the list offers three possible answers: "Yes", "Can't Tell", and "No". In keeping with the recommendations of previous research [76,77], the following scores were assigned to each of the qualitative response options: "Yes" (1 point), "Can't Tell" (0.5 points), and "No" (0 points). Thus, the ratings could vary between "High" (if "Yes" was obtained in two-thirds of the sections of the CASP list), "Moderate" (when the score oscillated between 4 and 6) and, finally, if more than two-thirds of the responses to the guide items were "No", its quality was evaluated as "Low".

Results of the Bibliographic Search
The information regarding the search and the study selection process is shown in the PRISMA flow chart ( Figure 2). The bibliographic search of the databases yielded a total of 651 records. Through cooperative work by academic peers at Mendeley bibliographic manager, 10 duplicate references were removed. Following the procedure proposed in the flowchart [52], in the third screening stage of the studies, after an independent review by title and abstract pairs of a total of 641 studies, 503 records were removed. Some of these studies reported by the databases appeared in a language other than English; however, when the titles and abstracts were examined, they were discarded along with the rest because they dealt with issues not related to the objective of the study. One hundred thirty-eight (n = 138) papers were selected for a full-text review, of which 16 records [3,13,39,41,48,[78][79][80][81][82][83][84][85][86][87][88] satisfied the selection criteria proposed for this research. Figure 2 shows the total articles deleted and the reasons for their exclusion.

Studies Included and Their Characteristics
After carrying out the different phases proposed in the flow chart, a total of 16 studies met all the eligibility requirements ( Figure 1) and were included in the review. The total number of studies dealt with issues related to trends in the accessible tourism market and included recommendations and guidelines to improve accessibility in destinations, the reception of tourists with special needs and tools for implementing them. Table A1 shows the main characteristics of the studies included in the synthesis. The studies span a period of 20 years (1998-2018). The sum of the samples from the different studies corresponds to a total of 728 participants, distributed throughout eleven countries. Most of the samples are made up of two reference population groups: (A) tourism service providers and (B) people with disabilities, with a higher incidence of people with physical disabilities. The age range of the samples goes from 18 to 72 years, with an approximate mean age of 45.3 ± 2.21 years.

Studies Included and Their Characteristics
After carrying out the different phases proposed in the flow chart, a total of 16 studies met all the eligibility requirements ( Figure 1) and were included in the review. The total number of studies dealt with issues related to trends in the accessible tourism market and included recommendations and guidelines to improve accessibility in destinations, the reception of tourists with special needs and tools for implementing them. Table A1 shows the main characteristics of the studies included in the synthesis. The studies span a period of 20 years (1998-2018). The sum of the samples from the different studies corresponds to a total of 728 participants, distributed throughout eleven countries. Most of the samples are made Five of the sixteen studies included dealt with the importance of motivation in disabled travelers [3,48,80,86,88]. Another five studies explored the possibilities and trends of the accessible tourism market, analyzing the perceptions of both travelers with PwD and managers of tourism-related companies [13,41,78,79,87]. Finally, six of the studies involved how to create accessible and inclusive tourist experiences, emphasizing the value of co-creation in the design of tourist spaces and experiences [39,[81][82][83][84][85].
Regarding the data collection and analysis methods, we noted that the most used instrument was the semistructured interview, and with respect to the analysis method, the most common within the studies analyzed was the thematic analysis. The cultural and geographical contexts and places where the studies were carried out varied. Formal contexts (academic and work spaces) were mainly found in studies whose samples consisted of managers of tourism companies. The samples in contexts related to small rural areas, including coastal areas, contained mainly travelers with disabilities (See Appendix A).

Results of the Assessment of the Methodological Quality
The methodological quality of the studies that were included in the synthesis was moderate (mean quality = 6.87). Only one study [81] was of low or inadequate quality. Eight studies [13,41,79,[84][85][86][87][88] showed moderate quality (representing 50% of the included studies). Seven studies [3,39,48,78,80,82,83] were rated as high quality. However, it should be noted that the studies that obtained the quality classification "high" had scores close to "moderate". A sensitive analysis showed that the quality of the studies may, to a certain extent, be conditioned by the span of the publication periods. No study was considered for elimination due to low methodological quality. The scores of the methodological quality of the studies according to the CASP Qualitative Studies Checklist are given in Table A1 (See Appendix A). For more information on the quality scores of each of the studies, see CASP, Supplementary Table S1.
These themes express the perceptions of the stakeholders in improving the future of accessible tourism, which is not limited to the elimination of physical, sensory, or communication barriers, but rather aims to ensure that tourism environments, products, and services can be enjoyed on equal terms by anyone, with or without disabilities.

The Motivational Autonomy of the Disabled Traveler
The challenge is to consider the disabled tourist as a tourist, not as a person with a disability, in order to prepare specific tourism products. It is essential to develop tourist proposals where the motivation of the traveler is the key, as well as to offer the support needed to allow travelers with disabilities to reinforce their own identity. The use of Information and Communication Technologies (ICTs) is very important for the positive development of tourist experiences [3,48,79,88].
In this sense, the disabled tourist must be understood as an independent person who strives for personal autonomy and the freedom to make their own decisions, to escape from a daily routine that is defined by their dependence on others. Different participants, in some of the qualitatively analyzed studies, show in their comments how their willingness to make decisions is biased and conditioned by their relational environment [48,88]: "I think it's because in everyday life, disabled people depend so much on the help of others and that makes it difficult for them to be free to decide things". [48] "Once I needed to travel for a long distance and it involved taking a flight. My mother tried to stop me from going and said it was very dangerous. She was so worried that she could not sleep for a few nights. Eventually, I did not go, as she had influenced my decision". [88]

Accessible Tourism Is a Real Business Opportunity
The new markets must be flexible to the real needs of the entire population. This requires providers to know the changing needs of their clients, which is why user participation in the design of the tourism product is key. With proper communication, coordination, and with the feedback from the tourist experience, the results can be surprising and can transform a traditional tourist company, which is more likely to set aside its negative views and its aversity to change, and which views accessibility as a "social problem", and to assume new challenges to improve its productivity [13,41,78,79,87].
In order to further develop the accessible tourism market worldwide, the tourism industry must seek strategies that allow it to grow at all times by diversifying and increasing its competitiveness through added values that exert a positive influence on the tourism experience, and by attracting new market segments that are capable of consuming those products that differ from the rest. When the needs of the entire population are not taken into account in the design of tourism products, said products are biased from the start, regardless of the capacities of the tourists. In contrast, when suggestions for the design of spaces meet the design parameters for all people, the tourism experience is inclusive. Exclusion can apply not only to physical environments, but to virtual and social ones as well; the "misinformation" or lack of accessible information by travel agencies frustrates any travel design [3,79]. The solution is to achieve inclusive tourism, which requires co-creation by the end users of tourism products together with companies. Co-creation includes several levels of participation, with broad perception and collaboration by the people interested in designing accessible and developed tourism for everyone. Based on the responses of tourism providers and business generators related to this market, the studies analyzed show that there is an intention on their part to accept proposals in the process of designing and creating value for services, experiences, and spaces [39,81,82,84,85,88].

Discussion
In this systematic review, an attempt was made to study, through an analysis and synthesis of qualitative evidence and based on the responses of the different stakeholders in the development of accessible tourism, those changes that will have to be made to improve the outlook of the accessible tourism market. In this regard, efforts were made to analyze at the same time those practices and emerging trends that are helping to achieve higher quality in the provision of services in the sector. Our findings are shown schematically in a circular-flow diagram of concepts on accessible tourism, where the contributions and interrelationships between the different stakeholders in the development of the sector can be clearly identified (Figure 3).
The disabled tourist seeks to escape from their daily routine, find their own autonomy and dependence in their vacation stays, and to do this, they need certain resources, spaces, and services that are accessible. People with disabilities value in the management of destinations the education, training, and experience of tourism service providers with disabled tourists, qualities that, according to studies carried out in this regard, need further development. At the same time, the value of co-creation and collaboration, as well as the use of ICTs, are emphasized. A greater effort aimed at improving these aspects is indicated in the qualitative literature through improved tourism inclusion, and greater satisfaction and empowerment on the part of clients, which will influence their motivation to travel, and therefore lead to increased demand. This has repercussions again on companies, generating economic and social advantages that enable said companies to increase their investment in accessibility and improving their products, which again yields increased demand, satisfaction, and motivation. This is how a circular cycle is produced between improvements in benefits and services and an increase in satisfaction, quality, demand, and motivation. where the contributions and interrelationships between the different stakeholders in the development of the sector can be clearly identified (Figure 3). The disabled tourist seeks to escape from their daily routine, find their own autonomy and dependence in their vacation stays, and to do this, they need certain resources, spaces, and services that are accessible. People with disabilities value in the management of destinations the education, training, and experience of tourism service providers with disabled tourists, qualities that, according to studies carried out in this regard, need further development. At the same time, the value of cocreation and collaboration, as well as the use of ICTs, are emphasized. A greater effort aimed at improving these aspects is indicated in the qualitative literature through improved tourism inclusion, and greater satisfaction and empowerment on the part of clients, which will influence their motivation to travel, and therefore lead to increased demand. This has repercussions again on companies, generating economic and social advantages that enable said companies to increase their Throughout time, tourism has been viewed as an exclusive activity, and the more exotic the destination and the more luxurious the experience, the higher the price that can be demanded [20]. In this context, inclusive tourism emerges as one of the trends that seeks to suppress social, economic, and spatial exclusion in tourism [53]. Inclusive tourism advances in line with what is presented in the Convention on the Rights of Persons with Disabilities (CRPD) (2006) [89], whose internationally agreed principles guarantee people with disabilities equal experience in all areas of citizenship. UNWTO, in its "Manual on Accessible Tourism for All: Principles, Tools and Good Practices" [90], notes that the inclusion of people with disabilities in tourism involves guaranteeing accessibility conditions for all, both in the facilities and in tourism products and services, and this must be addressed through responsible and sustainable tourism policies.
The results of our study indicate a series of problems inherent to the correct development of accessible tourism. The first refers to the understanding of the disabled tourist. The disabled tourist has a right to be treated like any other client. In their experiences, they look for products and services that can be enjoyed in the same conditions as anyone else. It is necessary to avoid paternalistic behavior on the part of tourism providers. The disabled traveler wants to free himself from his routine, from his role as an "object of care", and to promote his personal autonomy [48,91]. The findings in our study regarding the differentiation in the treatment and provision of services by tourist managers towards PwD are in line with previous studies, which had already warned of this phenomenon, despite the inclusive attitude shown towards groups by PwD [24]. However, it is important to respect their individuality and needs, since in many cases service providers have a stereotypical view that clients with disabilities have similar attributes to each other [92].
New technologies can undoubtedly provide a more sophisticated understanding of these different needs by directly influencing customer satisfaction in terms of ease of access to information. They are also useful for creating personalized profiles, where tourists can explicitly describe their individual needs and demands. This information may be more accurate if tourism operators take into account the contributions of Buhalis and Amaranggana (2015) [93], where the authors demonstrated the contributions to tourism of new technologies, and more specifically "big data", as they are useful tools for offering products and services that are better tailored to satisfy the unique needs and preferences of each visitor. In this regard, it is necessary to understand that the wishes of travelers are becoming increasingly critical for competitive tourism markets.
Regarding the second analytical issue, it states that accessible tourism has certain advantages in a market as competitive as the tourism industry is almost obvious, as has been demonstrated in different studies carried out around the world [94][95][96]. Tourist destinations remain in constant competition internationally, with increasingly demanding consumers requiring not only quality, but also socially responsible and sustainable destinations [47,97]. The contributions of our study in this regard focus on synthesizing those strategies that will lead tourism companies to take on new challenges that will allow them to diversify, improve, and add value to their accessible services and services. Three issues were deemed fundamental to improving the accessible tourism market: Education/Training, Collaboration/Co-creation and Use of New Information and Communication Technologies (ICT) [82][83][84].
Research on the impact of disability awareness training in the tourism industry has shown that it can prove to be a valuable resource, especially for changing the attitudes of professionals towards disabled clients. The main reluctance of employees in the tourism sector to come into contact and collaborate with clients with disabilities is their low experience and knowledge in this area. These limitations should be addressed through secondary and higher education programs in the field of tourism, perhaps by steering these programs to a greater extent towards practice [98,99]. Some practices have shown how specific short programs on disability training can change the attitudes of employees, not only in the hotel sector, but also in travel agencies, restaurants, among others, towards customers with disabilities. This is of vital importance for the design of study plans, since it has been shown that there are few plans and programs that address the issue of people with disabilities in disciplines related to tourism and hospitality [100].
Companies in the sector need to develop solid strategies to co-create value with their clients, as this will guarantee innovation and quality in the provision of products and services [48]. In addition, those factors that have a significant impact on the co-creation of value have already been identified as follows: the relationship between clients with disabilities and the workforce (23.5%), the training of said staff (20.6%), the environment (20.3%), and collaboration itself (14.4%) [101]. Taking these data into account, tourism providers would already have a reference guide that can orient them in their efforts to improve their products and services. To undertake novel value co-creation proposals, tourism and hotel service providers can take advantage of advances in ICT. The relationship between clients and tourism providers, mediated by a mobile instant messaging context, has already been reviewed in recent research and determined to be a successful system due to its effects on the perceived value of client personalization [102].

Limitations and Implications
The present study is not without limitations, the first of which refers to the fact that most of the articles focus on a specific group, such as people with physical disabilities. The studies analyzed do not distribute their samples by age in most cases, nor did the majority of them provide statistics by gender. Future accessible tourism reviews could focus their attention to a greater extent if they limit the field of research by type of disability, or by age group. Specific results can be difficult to obtain if these divisions are not taken into account, since the needs of the different sectors will vary greatly. However, the contributions of this research may be useful to better understand the changes that the various stakeholders are demanding for the accessible tourism sector, as well as to rethink possible strategies that can improve the quality of tourism resources and services. The data in this study should be treated with caution. We approach the phenomenon of accessible tourism using a qualitative paradigm and inductive methods of knowledge in an effort to better understand the continuing trend in this field. Other limitations refer to the low number of studies included in this systematic review and to the fact that they are all covered from a qualitative research paradigm. Only 16 articles met the inclusion criteria and were analyzed in depth. Future systematic reviews could address those needs, barriers, and difficulties encountered by the different stakeholders in the development of the tourism sector. Starting from the notion of the accessibility chain, which ensures that a space can be reached, accessed, used, and left without this flow being broken at any time, an assessment could be made of the extent to which the tourism industry can be considered accessible. This requires the contributions from both quantitative studies, which could be used to account for the frequency with which accessibility problems are encountered, as well as from qualitative studies, which would allow describing the perceptions, visions, and feelings, as well as the meaning that accessibility has, for the different parties involved.
Regarding the implications of the study, having analyzed and synthesized the qualitative evidence found in the field of accessible tourism research, it seems relevant to conclude with a series of practical recommendations. In this regard, we can say that the agents involved in the tourism experience have to bear in mind the seven phases of the travel process if their products are to succeed, namely: motivation or how to attract the client to the destination, search, planning, decision, reservation, the trip, and the sharing.
In all of these phases, the following are essential: (1) Hypersegmentation-assess which tourism providers can offer a better service. The aim is to offer a personalized, authentic experience that can be shared. (2) Analyze the tourism environment-make sure that the space where the tourism service offered is safe, friendly, and usable by the traveler. (3) Train the human resources that staff the tourist resort.
(4) Provide accurate information about the service and everything related to it, including transportation, nearby facilities, etc. All travelers value information on the services they hire, and in the case of people with a disability, information is even more important. (5) Analyze whether the website is accessible to everyone. In addition to providing accurate and complete information on services and facilities for people with disabilities, we must ensure that content is accessible to all travelers. (6) Ask travelers to rate their experience.
Other contributions derived from the emerging issues in this study can be summarized as follows: tourism companies have to know everything related to the behavior of tourists with disabilities; they will also have to design campaigns that focus on emotions. Emotion marketing aimed at this business target is the first step in motivating the disabled traveler.
By systematically analyzing the demands of travelers with disabilities, it is possible to identify the insights that will allow tourism providers to develop products or campaigns that are more in line with what these travelers are seeking, as well as to create messages that can significantly impact the target market. Being aware of these changes and knowing the methods for reaching disabled travelers through effective tools and strategies yields an expanded panorama of marketing options, which can then be assessed so that those that are best suited to the tourism services can be applied in order to consolidate the reputation of the destination. This, together with the emotions and confidence of the consumer, are crucial to determining how satisfied tourists will be during their visit to a tourist destination. The ultimate goal is to create effective bonds between brand and consumer, to meet their needs, and thus turn that disabled traveler into an advocate for the brand.

Conclusions
This systematic review of the literature shows how there is still segmentation and a lack of knowledge about what accessible tourism means. Tourism providers need to understand in greater depth what tourism means for PwD-an opportunity to escape from their routine patterns and to exercise their own autonomy as people with rights. Tourist accessibility is a competitive advantage in the tourism industry, but training and training strategies must be developed, products and services have to be co-created, and the opportunities that new technologies offer the entire process have to be leveraged if we are to guarantee quality in the sector. In addition to the economic case made above, three further arguments justify the need to improve accessibility: the ethical-political argument, which entails nondiscrimination; the legal and regulatory argument, due to the mandatory compliance with the existing legislation on accessibility in each country; and the demographic argument, where the population benefiting from accessibility is increasingly numerous. Better knowing the individual needs of tourists with disabilities creates advantages in the competitive tourism market, and also has a direct impact on the satisfaction and motivation of PwD to travel. This becomes an economic cycle of circular flow since tourism service providers, by improving their accessibility conditions and guaranteeing tourist inclusion, increase motivation, satisfaction, and brand loyalty, which can lead to an increase in demand and provides companies the opportunity to make new investments in accessibility.

Supplementary Materials:
The following are available online at http://www.mdpi.com/2071-1050/12/24/10507/s1, Table S1: CASP (Critical Appraisal Skills Programme) qualitative checklist scores for all of the studies included.  complete information on services and facilities for people with disabilities, we must ensure that content is accessible to all travelers. (6) Ask travelers to rate their experience.
Other contributions derived from the emerging issues in this study can be summarized as follows: tourism companies have to know everything related to the behavior of tourists with disabilities; they will also have to design campaigns that focus on emotions. Emotion marketing aimed at this business target is the first step in motivating the disabled traveler.
By systematically analyzing the demands of travelers with disabilities, it is possible to identify the insights that will allow tourism providers to develop products or campaigns that are more in line with what these travelers are seeking, as well as to create messages that can significantly impact the target market. Being aware of these changes and knowing the methods for reaching disabled travelers through effective tools and strategies yields an expanded panorama of marketing options, which can then be assessed so that those that are best suited to the tourism services can be applied in order to consolidate the reputation of the destination. This, together with the emotions and confidence of the consumer, are crucial to determining how satisfied tourists will be during their visit to a tourist destination. The ultimate goal is to create effective bonds between brand and consumer, to meet their needs, and thus turn that disabled traveler into an advocate for the brand.

Conclusions
This systematic review of the literature shows how there is still segmentation and a lack of knowledge about what accessible tourism means. Tourism providers need to understand in greater depth what tourism means for PwD-an opportunity to escape from their routine patterns and to exercise their own autonomy as people with rights. Tourist accessibility is a competitive advantage in the tourism industry, but training and training strategies must be developed, products and services have to be co-created, and the opportunities that new technologies offer the entire process have to be leveraged if we are to guarantee quality in the sector. In addition to the economic case made above, three further arguments justify the need to improve accessibility: the ethical-political argument, which entails nondiscrimination; the legal and regulatory argument, due to the mandatory compliance with the existing legislation on accessibility in each country; and the demographic argument, where the population benefiting from accessibility is increasingly numerous. Better knowing the individual needs of tourists with disabilities creates advantages in the competitive tourism market, and also has a direct impact on the satisfaction and motivation of PwD to travel. This becomes an economic cycle of circular flow since tourism service providers, by improving their accessibility conditions and guaranteeing tourist inclusion, increase motivation, satisfaction, and brand loyalty, which can lead to an increase in demand and provides companies the opportunity to make new investments in accessibility.

Supplementary Materials:
The following are available online at www.mdpi.com/xxx/s1, Table S1: CASP (Critical Appraisal Skills Programme) qualitative checklist scores for all of the studies included.

Conflicts of Interest:
The authors declare no conflict of interest. Conflicts of Interest: The authors declare no conflict of interest.  [48] In-depth interviews and focus group interview. Extensive ideographic analysis.

Denmark
Reflections on the efforts that tourists with disabilities have to face, as well as their motivations and vacation decision-making.
Rural and urban setting in Denmark Total (n = 21) 10 respondents and 11 experts Sex: 16-F 5-M Ages:  Disabled tourists go on holiday primarily to escape from their role as care receivers. Decision-making while on holiday is much more complex for disabled tourists than for other tourists.

United States of America
Identification of needs and perceptions of guests with disabilities in relation to their experiences at the hotel. Analysis of the feasibility to carry out their suggestions in the design of the hotel and its service policies.

Major cities in Florida
Total (n = 9) Guests with mobility impairments Sex: Not specified Ages: Not specified Responses from guests with disabilities offer suggestions and express needs for special accommodations. PwD request more sensitivity training from hotel managers and workers.

China
Perceptions of people with disabilities on the effectiveness of travel agencies.
Hong Kong urban context, disabled people Total (n = 52) People with mobility and visual impairments.
Sex: Not specified Ages:  There is discrimination regarding information on tourism products and services for PwD. The need for tour agents to promote travel is underscored.
Exploratory data analysis.

Spain
The value of co-creation in tourism companies. How can people with disabilities contribute?
Hotel industry in a Spanish city on the Mediterranean coast Total disabled tourists = 10 Sex: 5-F 5-M Total hotel managers = 6 Ages: 30-60 Total (n = 16) The help of this co-creation in increasing the benefits for participants is highlighted.  [85] Semistructured, in-depth interviews.
Data analyzed thematically using case-ordered metamatrixes.

Denmark and Germany
The importance of perceptions from the supply side to guarantee the quality of accessible tourism.
Two national contexts: Denmark and Germany. National context of researchers. Four nonarbitrarily selected cases.
Total (n = 84) Tourism providers Sex: Not specified Ages: Not specified The results of this study indicate that to facilitate leisure for people with disabilities, it is not enough to follow one model of disability or another (medical or social models). The truth is that this is a more complex task that depends rather on: following a more systemic approach to accessible tourism; Implications of further research on accessible tourism and tourism providers.

Australia
Stakeholder collaboration for the development of accessible tourism.
Rural context. Specifically, it focuses on Margaret River, a city in the south-west of Western Australia.
Total (n = 18) People with disabilities; Organizations of people with disabilities; H&T service providers; Government agencies Sex: 9-F 9-M Ages: 20-70 To achieve accessible tourism when there are multiple actors, it is necessary to adopt a circulatory approach of development and collaboration. For this, the authors consider it necessary to develop a framework that takes into account; -Control and coordination, communication, clarity in roles and responsibilities, and collaboration and integration.

China
Difficulties and problems for PwD to participate in tourism, from their own perceptions.
Known groups of Hong Kong tourism consumers Total (n = 86) Disabled tourists Sex: 49-F 37-M Ages: Not specified A reciprocal relationship can be observed between the context of the trip and the process of becoming or staying active in it. The process of becoming an active traveler comprises six stages, where environmental and personal factors contribute to the explanation of the complex relationship between tourism, disability and environmental contexts.

Australia
Attitudes and experiences of Australian tour operators in relation to the provision of services and products to tourists with disabilities.
Northern Australia. More specifically in the state of Queensland.
Total (n = 32) Tourism operators Sex: Not specified Ages: Not specified Accessibility to public transport and tourist attractions in the state of Queensland has improved and this has significant financial implications. Tour operators are making a significant effort to make their products and services more accessible. The motivational aspects identified to improve accessibility include greater availability of financial support and more moral, personal and emotional rewards. The qualitative results indicate that travelers with disabilities undergo five stages to become active travelers (personal, reconnection, tourism analysis, physical travel and experimentation and reflection). If tourism providers and the rest of the population understand these stages better, a greater awareness of the tourism needs of people with disabilities can be achieved.