This study was a 30-day, single-arm pilot trial involving carers supporting people diagnosed with cancer. We chose colorectal cancer as it affects both men and women and is the third most common cancer worldwide [15,16].

We recruited carers of colorectal cancer patients from the second largest public health service and the largest not-for-profit private health service in Victoria, Australia. During 6 months, the public health service treated 105 people with colorectal cancer and the private health service had 273 admissions. Between October 2017 and May 2018, we approached carers during the patients’ chemotherapy appointment and provided them with an overview of the study. Patients nominated carers as being their main support person at home. Interested carers were provided with a recruitment pack (participant information sheet, consent form, and demographic questionnaire) to take home. When carers were unavailable at appointments, we approached patients, gave them an overview of the study, and asked whether their carer would be willing to participate. We asked the patients to take home the carer recruitment pack and sought initial consent via telephone to the carer within 48 hours to confirm participation. All carers provided written informed consent.

Adult carers of adult patients with colorectal cancer who were receiving chemotherapy or radiation treatment as day patients, either initial, recurrent, or secondary to surgery, were invited to participate. Carers were required to be in possession of a smartphone or tablet device and have internet access. At the end of the 30-day trial, carers received 2 reminder phone calls to return follow-up questionnaires. Follow-up occurred between November 2017 and May 2018. We obtained ethics approval from Deakin University (2017-218), Eastern Health (HREC/17/EH/24), and Epworth HealthCare (EH2016-169).

We developed the Carer Guide App using a codesign approach to address needs that carers identified in previous research [6,17,18]. A full description of the development process of the Carer Guide App is currently under review. The Carer Guide App was organized into 7 sections, each providing detailed information to address carers’ needs: Cancer Information, Carer Information, Well-being, My Social Network, Financial and Legal, Hospital Information, and Medical Terminology. In addition, two resources were provided: a Notepad and Contacts, which contained contact details for national information and support organizations and allowed carers to enter personal contact information. All carers had access to the Carer Guide App for 30 days and received 2 email messages each week directing them to information and services available within the app. Email messages related to carer health and well-being and support were available to carers. Messages were developed for each section of the Carer Guide App and provided information or reminders about the support that was available and where to locate this information within the Carer Guide App.

Upon enrollment in the study, carers provided a contact email address. We entered the nominated email address into the Carer Guide App system, which sent an automatically generated welcome email to carers. The welcome email included a link to download the Carer Guide App, a user identification number, password, and links to videos with instructions on how to download and navigate the Carer Guide App on both Android and iOS devices. Carers were provided with an email address to contact the research team for further technical support if required.

We analyzed data using IBM SPSS (Version 25; IBM Corp). Feasibility, usability, and acceptability were analyzed by the frequency of agree (4) and strongly agree (5) responses. Demographic data and app usage from Google Analytics were analyzed using descriptive statistics.

Of 85, a total of 26 (31%) carers consented to participate in the study, of which 20 (77%) used the Carer Guide App and 19 (73%) completed the follow-up questionnaires (attrition rate 7/26, 27%). Of the 7 carers who did not complete the follow-up questionnaire, 1 used the app and 6 did not use the app. There was 1 person who completed the follow-up questionnaire but did not use the app as he or she was not in need of it at the time. Figure 1 outlines the recruitment process.

The mean age of carers was 57 (SD 12; range 30-79) years. Of the 26 carers, the majority were female (19, 73%), caring for a spouse (26, 73%), and held a tertiary-level qualification (19, 73%); furthermore, the main device type used by carers was smartphones (15, 58%). There were 2 carers who accessed the Carer Guide App on their desktop computers (Web app version). Table 1 outlines the full demographic characteristics of the sample.

The appearance and function of the Carer Guide App were reported as usable by the majority of carers; 17/19 (89%) found the font size appropriate, 13/19 (68%) found it easy to move between pages, and 11/19 (58%) stated that required information was easy to find. There were 4 carers who viewed the video instructions on how to download and navigate the Carer Guide App. The Carer Guide App’s email address was used by 7 carers to contact the research team with questions related to setting up the app on their phone or to provide comments in response to reminder emails sent.

The majority of carers (16/19, 84%) agreed that the Carer Guide App should be available for all carers. Furthermore, 42% (8/19) stated that they used the app when they wanted more information and 42% (8/19) stated that they would like to continue using the app, while only 11% (2/19) reported that they used the app for support.

The Carer Guide App was developed in collaboration with carers to improve their access to information and support while looking after another adult with cancer. Overall, the Carer Guide App was a feasible option given the feedback received from participants. Carers perceived the content to be appropriate, and the links within the Carer Guide App led to relevant information. Certain sections of the app were perceived as more useful than others. However, all sections of the app received positive responses. These findings are comparable with Web-based interventions among people living with prostate cancer, where 47% of the people were satisfied with the program [21]. Differences in the perceived usefulness of the app sections may have several explanations. The type and amount of unmet needs experienced by carers constantly change [5]; therefore, a 30-day period to assess the appropriateness of content in addressing carers’ needs may not be long enough. Similarly, carers may experience different types of needs during different stages of the illness trajectory [22-25]. The static information provided in the Carer Guide App may not support needs as they evolve. Further, carers who had been in the carer role for a prolonged period may already have sourced the information and support required. It is possible that the Carer Guide App provided carers with information and resources that they were previously unaware of; however, more research is required to assess this. Despite these findings, 85% (16/26) of carers stated that the Carer Guide App should be available to all carers, and this is comparable to other studies evaluating the feasibility of cancer-related Web-based interventions [21].

Generally, carers found the email messages helpful in highlighting resources available within the Carer Guide App. Carers perceived the structure of the Carer Guide App as easy to navigate and locate information. Email support was used by several carers to enhance their experience and provide further instruction on using the app. These findings confirm the usefulness of technical support to aid the use of technology-based interventions for carers previously reported in the literature [6].

With a total of 71 log-ins and an average usage of 22 minutes over the 30-day trial period, the Carer Guide App was assessed to be acceptable to carers. Users often disengaged from sites within 10-20 seconds if they were unable to locate information [26]. As the average use in our sample was 22 minutes, this suggests that the Carer Guide App was acceptable for the information and resources provided within it. App usage varied greatly depending on the purpose of the app, and previous research has required participants to log in a specific number of times [10]. In another study involving a smartphone app providing static information for dementia, usage was on average 5 minutes for the duration of the 4-week period [27]. Further, findings of previous research suggested that smartphone apps did not impose a time burden on participants, and they could be incorporated into a daily routine from anywhere between 3 days to 1 year [10,11]. Carers reported that the Carer Guide App should be available to all carers, and suggestions for further improvements were mainly individual requests for specific information, resources, or design changes.

The recruitment rate of the study was modest (26/85, 31%); however, this is consistent with findings from previous research, where recruitment among this population can vary from 20% to 60% for technology-based intervention studies [6].

Carers’ willingness to use smartphone apps and their need for this type of support may be impacted by patients’ stage of illness, carers’ knowledge of support available, and carers’ current support network. Future research may consider assessing smartphone app support at a certain stage of patients’ illness, for example, at diagnosis, to test its potential impact. This may provide information about the relevance of content to carers’ current and future needs, the ability of a smartphone app to meet needs, and carers’ likelihood of using a smartphone app during this stressful period. Future studies may also consider measuring carers’ knowledge of alternative support available and the presence and strength of their support network.

The sample was largely homogenous, with the majority of participants being female and highly educated, with all participants speaking English. In the general population in Australia, 31% has tertiary-level educational qualifications, [28] compared with 73% (19/26) of our sample, and 21% speak a language other than English at home [29]. Future studies should include larger samples to gain insights into feasibility, usability, and acceptability among a more heterogeneous sample. The duration of the caring period and patients’ stage of illness were not collected, which further limited the ability to determine whether the Carer Guide App was more feasible during specific stages of the caring or illness trajectory.

A smartphone app may be appropriate for providing carers with more information and resources if the content is specific to their needs and provided at an optimal time during the caring period. The Carer Guide App is a feasible and acceptable method for delivering information and support to carers of people with colorectal cancer. Future iterations should include more specific information to enhance the acceptability of the App. Further research, including a randomized controlled trial, is recommended to assess whether a smartphone app has the potential to improve health and well-being outcomes and reduce unmet needs among carers.