Cancer is a significant issue worldwide with over 14 million people diagnosed in 2012 [1] and is estimated to account for 9.6 million deaths in 2018 [2]. Globally, US $1.16 trillion are spent on cancer every year [2]. The financial burden on health care systems has resulted in quicker discharge times for patients and increased the need for care to continue in the community [3]. In Australia, there are approximately 2.7 million informal carers who are not paid for the care they provide [4]. Informal carers are often family members who may have limited awareness and understanding about the disease to sufficiently meet the care needs of individuals [5]. As a result, physical, mental, social, and financial burdens are common among carers resulting in negative health outcomes and poor well-being [6].

Carers often neglect their own needs while looking after someone with cancer [7,8]. Face-to-face support through local medical and counseling services can be costly, time consuming, and inaccessible to carers who are unable to leave care recipients alone or live in remote areas [9]. Technology may provide a solution in addressing the needs of many carers.

Technology-based tools allow large audiences to have access to information and support networks when addressing specific health needs [10]. Smartphone apps allow individuals to access information and support at a suitable time when needed and in the privacy and comfort of their own home [9,10]. Recent trends have shown increasing availability of 4G internet connection worldwide [11], and by 2020, 70% of the population is expected to own smartphones [12]. Although these figures suggest that smartphone and roaming internet access is common, individuals use technology in varying ways; therefore, it is important to assess carers’ attitudes toward digital technology as a supportive tool. Existing cancer information and support helplines are not widely recognized or used among people affected by cancer, and carers only account for approximately 20% of people who initiate contact [13,14]. Web-based interventions have been found to be appropriate for use among carers and are accessible to a larger number of people [15]; however, they are not always available through smart devices, and this can limit carers’ ability to access support in times of need [16]. Previous studies have shown positive results for the use of smartphone apps across different circumstances including self-management of cancer [17,18], for carers of pediatric illness [19,20], and for children with cancer [21]. However, there have been no studies assessing the use of smartphone apps among adult carers providing care to another adult with cancer [15].

This research was guided by 2 theoretical frameworks. The theory of planned behavior (TPB) and the unified theory of acceptance and use of technology (UTAUT). TPB applies 3 concepts—behavioral beliefs, normative beliefs, and control beliefs for understanding social and personal reasons for using technology [22].

The concept “facilitating conditions” within UTAUT measures external factors contributing to technology use such as the ownership of a smartphone device and internet connectivity [23].

User centered design (UCD) is a philosophy to guide the design of interventions to meet needs, preferences, and characteristics of users, using a lifecycle process of context, requirements, design, and evaluation [24,25]. UCD has been used to develop technology-based interventions among a variety of populations [26-28].

The aim of this study was to design a smartphone app prototype for carers of adults with cancer.

This study comprised a multiple-methods design to inform development of the app and included the following 3 sequential phases: (1) focus groups and phone interviews with present and past adult carers to assess their information and supportive care needs as well as their attitudes toward smartphone technology, including existing barriers affecting technology uptake; (2) smartphone app design, content development, and app programming; and (3) alpha and beta testing and user testing of the app. Findings from phase 1 informed the design of the app and its content. Data were collected between May 2016 and August 2017. Ethics approval was obtained from Deakin University Human Research Ethics Committee, from 2016 to 2018.

The context of carers of people with cancer and their needs from a smartphone app were identified in phase 1 via focus groups and interviews. TPB and UTAUT guided the development of the app in terms of its structure and function (eg, font size and navigation) and accessibility to carers’ with varying skills and confidence in using smartphone apps. The design phase was completed by combining these results. Evaluation occurred during alpha and beta testing through paper-based and app-based user testing. Between paper-based and app-based testing, the needs of participants were identified, and the design solutions to match these needs were performed and evaluated in line with the UCD methodology.

TPB and UTAUT were incorporated into the development of the smartphone app across the different stages. See Table 1 for an outline of how the frameworks were applied to support development of the app.

The majority of carers were female (60%, 27/45), a spouse (64% 29/45), living with the person receiving cancer treatment (87%, 39/45), held a university degree (47%, 21/45), and caring for someone with breast cancer (30%, 11/45). Carers age ranged from 21-80 years (SD 14) with mean age of 55 years. See Table 2 for full demographic information.

Carers provided varied ideas for content that could be included in the app. Overall, carers reported a need for more cancer-related information, links to support services and social networks, case studies, interventions to manage symptoms at home, information on how to identify serious side effects, and when to escalate care, on hospital-specific navigation, and resources to manage their own needs. Resources mentioned included—calendar with symptom tracking, reminders for appointments and medications, notepad, contacts, a search function, and the ability to synchronize the app with other phone functions. Carers specified that the app should have information specific to their needs and the use of push notifications was regarded as beneficial because the app would be perceived as less impersonal.

Some carers felt that more than 1 person could facilitate their use of a smartphone app. Overall, 15% (5/33) carers would not be influenced by others to use an app and were more likely to prefer using the computer or talking face-to-face with a health care professional. Refer to Table 3 for a full summary of results related to theoretical frameworks and their implementation into practice.

Results from phase 1 indicated that carers required the app to be specific to their information and support needs. Initial development decisions included—app name, color scheme, logo and icon pictures, and the layout structure. To ease navigation, similar content materials were grouped together under 1 main category; this is shown in Figure 3.

Caring for someone with cancer can be stressful, and information and support are not easily available [33,34]. The Carer Guide App was developed to support carers while caring for someone with cancer. Carers may be reluctant to communicate their own needs and struggle to find information that is specific to their own situation [35]. The Carer Guide App provides a means for carers to access information and support anywhere within their internet connection capabilities and allows carers privacy in addressing their needs [9].

The development followed a co-design process, which sought involvement from stakeholders throughout the design and creation phase of development [36]. Involving carers in the creation of the Carer Guide App enabled the content to be designed specifically for carers’ needs. The sample was a heterogeneous group, with participants caring for people with different types of cancer, of different ages, and various stages of caring including new, ongoing, recurrent, or past carers. This allowed the Carer Guide App to be designed to address the needs of carers from a variety of clinical, demographic, and social perspectives. Involvement of stakeholders in the development of technology-based interventions is an important part of UCD to ensure systems match users’ needs [25]. Using interviews to learn about stakeholders needs have been used among a variety of different groups including people with mental illness [37], among parents and teenagers with asthma [38], and for improving physical activity among people with chronic illnesses [39]. These studies found similar results, suggesting that intervention content should be highly relevant to stakeholders' needs, and in an easy-to-use format [37,38]. During user testing, inclusion of noncarers was important as not all people have previous experience with cancer before becoming a carer. This allowed the Carer Guide App to be tested among people with no previous knowledge of how to address cancer-related needs. Both the UAT and the UX testing showed that participants found the appearance of the Carer Guide App favorable. Issues with navigation during UAT were amended, and participants in the UX test were more easily able to navigate the Carer Guide App. Results from the UX test highlighted the need for specific instructions to accompany the Carer Guide App. UX has been used in the literature to capture design and navigation flaws before larger trials or integration into practice [18]. Tying in with the theoretical frameworks, the Carer Guide App was used successfully among people with varying levels of confidence. Feedback during phases 1 and 3 demonstrated participants’ positive attitudes toward the development of the Carer Guide App. Factors potentially affecting Carer Guide App usage included recommendations from health care professionals to use the app. The influence of health care professionals on carers’ information-seeking behavior is consistent with findings from previous research [40-42] and highlights the need to involve staff working in oncology settings in the implementation process for new interventions or services. Barriers to using apps included not having access to a smartphone or the internet; however, this only affected 9% (3/33) of this sample. Furthermore, smartphone ownership is expected to increase over time, suggesting smartphone apps are a relevant way to deliver resources to carers [12].

The concepts from the theoretical frameworks were easy to measure and relevant to the development process and could be implemented in any stage of the project. Findings from the theoretical framework provided the study with baseline results about the appropriateness of a smartphone app for carers of people with cancer and highlighted potential dissemination methods, for example, health care professionals to guide future research.

Although participants were engaged during the development of the Carer Guide App, it was not possible to meet the requests of all carers. For example, requests to include interactive features may affect the overall usability for carers who may be less confident in using apps. As a result, interactive features such as discussion boards and symptoms trackers were not created in this version of the app, and synchronizing features were not included in the app.

A second challenge was creating the app within the time frame of the research project. The Carer Guide App was developed as a Web-based app. Although Web-based apps are quicker to develop and launch and easier to modify, it required a different approach to downloading the app. Using the Web-based app, participants were required to create a shortcut icon and navigate through browser windows when external links were accessed from the Carer Guide App. These factors required testing during the UX test to assess whether participants could understand and navigate these factors and identified the need to develop video instructions for carers to assist them in completing these tasks. However, development of a Web-based app allowed secondary analyses to occur to assess which devices carers used on the Carer Guide App, for example, a phone, tablet, or computer; this may allow for an in-depth analysis about the applicability and acceptance of smartphone apps among carers.

To the researchers’ knowledge, this app is the first of its kind as carers guided its development, including the content, visual presentation, and layout. This research used a co-design process by involving carers (as stakeholders) during each phase of development and seeking user feedback to improve system functionality. This approach may be useful for future research to guide the development of novel interventions. Another strength of this research was the inclusion of current carers of a variety of cancer types and stages as well as past carers during focus groups and phone interviews. This enabled the content of the app to be created to meet the needs of carers across the illness trajectory.

This study has several limitations including the collection of information from carers living in metropolitan areas only, who spoke English. This may have resulted in the development of an app that is not appropriate for carers living in rural and remote areas or who speak a primary language other than English, as they may experience different needs. The Carer Guide App was not designed to synchronize to other phone functions because of the need to incorporate additional security measures. Not synchronizing the Carer Guide App to phone functions decreased the need for security passwords to access the app; this reduced any burden of having to remember passwords in times of stress by recipients.

Interactive features such as symptom tracking and calendars were not incorporated into this version of the Carer Guide App as they required an extended amount of time to create and test. When developing interventions with interactive features or the ability to synchronize to other phone functions, future researchers should consider the development time frame of their intervention, including the time needed to launch apps through Google Play and the App store.

Future research is needed to assess the applicability of apps for carers living in rural and remote areas and those whose primary language is not English. These groups of people may experience different needs and therefore require other information and services within an app.

On the basis of the development of the Carer Guide App outlined in this study, a pilot study is assessing the feasibility, usability, and acceptability among carers looking after people with 1 type of cancer. Findings from the pilot study will complete the UCD process by providing information about the suitability of the Carer Guide App among this population.

In conclusion, carers require information and support during the caring period. A smartphone app may provide 1 solution to address these needs. A pilot study is currently underway to test the feasibility, usability, and acceptability of the Carer Guide App.