Mobile health has received increasing attention from researchers, practitioners, and other stakeholders as the ubiquity of mHealth tools allows the delivery of the right intervention to the right person at the right moment (e.g., [1, 2]). The mHealth approach is expected to play a particularly important role in promoting physical activity (PA), which is effectively and efficiently supported by smartphone applications (apps) and wearable activity trackers that implement various behavior change techniques [3–5]. Several controlled and uncontrolled trials have assessed and established the efficacy of mHealth interventions for PA, and umbrella reviews have concluded that most mHealth interventions are effective albeit documenting high heterogeneity [6–8].
Regardless of their clinical and economic impact [9, 10], mHealth interventions face important issues in implementation and distribution, namely poor retention rates for commercial app users. These challenges are a general issue for healthcare apps that is not limited to PA apps, as research indicates that only 4% of users who install mental health apps continue using the apps daily [11], and the median monthly usage time of mHealth apps, including both mental and physical health, is no more than 5 minutes [12]. Active user engagement has been suggested to be associated with the quality of product design [12]; for example, reward and personalization functions may contribute to a good retention rate. One longitudinal study of commercial PA apps equipped with these functions suggested that 60% of users maintained active app use for at least six months [13]. Interestingly, the retention rate in randomized controlled trials of mHealth interventions is estimated to be 91%, which is much higher than that of commercial apps on the market. Thus, the discontinuation of app use is a unique phenomenon that can be observed in a daily, free-living context where no external regulation is expected by healthcare professionals or researchers. Believing that a good product spreads spontaneously by word of mouth would be somewhat naive, given that an explosive number of products appear and disappear on the market annually. Knowing what factors are predictive of the continuation of app use is particularly important for stakeholders, as it can help build an effective strategy to facilitate and maintain app use, resulting in healthy lifestyle changes. Therefore, we aimed to explore how people continue using apps to support PA and exercise to clarify the technology appropriation processes.
Appropriation perspectives
Appropriation is the way people adapt, adopt, and integrate new technology into their daily lives [14–16]. Carrol et al. [15] distinguished between technology-as-designed (i.e., the way of use that developers and designers intended) and technology-in-use (i.e., how technology is currently used). Through an appropriation process, users implicitly or explicitly transform technology-as-designed into technology-in-use—that is, they “trial and evaluate a new technology, select and adapt some of its attributes and so take possession of its capabilities in order to satisfy their needs” (p. 4). New technology must go beyond how it is designed by developers to become part of users’ daily routines, and this process often involves users’ active adoption and integration (e.g., reshaping and customizing a mobile device).
An increasing number of studies have investigated mHealth adoption, most having a theoretical basis in the technology acceptance model (TAM) and unified theory of acceptance and use of technology (UTAUT and UTAUT2) [17]. The TAM highlights perceived usefulness and ease of use as fundamental determinants of user acceptance of information technology [18, 19]. Conversely, UTAUT highlights four constructs (i.e., performance expectancy, effort expectancy, social influence, and facilitating conditions) and three extensions (i.e., hedonic motivation, price value, experience, and habit) influencing the intention to use new technology. Empirical studies have shown that perceived usefulness and ease of use are significantly associated with continuance intention to use health apps on smartphones [20], and these perceptions can be explained by external variables such as health consciousness, subjective norms, and Internet health information use efficacy [21]. Similarly, the UTAUT constructs (e.g., performance expectancy, effort expectancy, and social influence) have been shown to have a significant impact on users’ behavioral intentions to adopt mHealth services, although some inconsistencies have been documented [22, 23].
The Mobile Phone Appropriation Model
Technology adoption models, including the TAM and UTAUT, typically target binary use intention, namely either the adoption or rejection (and use or non-use thereof), as the dependent variable. However, Wirth et al. [16] argued that appropriation is a more complex concept that cannot necessarily be boiled down to the adoption-rejection dichotomy, which ends in various usage and meaning patterns at the individual and social levels. The Mobile Phone Appropriation (MPA) model explicitly theorizes the multifaceted patterns of everyday integration of mobile/smartphones and individual apps [17, 24, 25]. This model assumes two aspects of usage—symbolic and functional. The former represents the goal for which a mobile phone or app is used, also known as the gratification dimensions [16, 26]. Stehr et al. [24] applied the MPA model to their analyses of nutrition app use and divided the functional aspects into the following three subdimensions: distraction (i.e., using an app for pastime), lifestyle management (i.e., continuous monitoring and tracking of users’ own health states and behaviors to fulfill informational needs), and building relationships (i.e., exchanging with like-minded peer users, seeking and receiving support from peers, and competing with other users). Symbolic aspects are subdivided into psychological and social dimensions pertaining to behaviors important to the users themselves and in relation to their social surroundings [24]. These aspects cover preference and suitability (e.g., how the user likes the app and how the app fits the user), as well as prestige and identity, using the app as a way of expressing the user’s sense of self in public, such as in a fashion statement [17, 27]. The MPA model places the functional and symbolic aspects of use in a cycle of appropriation, in which metacommunication (i.e., communication on how individuals use an app) and evaluations (e.g., prospects about future app use for functional and symbolic aspects, beliefs about social norms, and barriers hindering app use) dynamically interact with and influence app use behavior.
Evidence gap
Although the MPA model is a comprehensive and sophisticated framework for analyzing different app use patterns, empirical evidence is still lacking on how predictive the model is for the actual continued use of a healthcare app. The model correctly points to the importance of understanding user behavior with multifaceted aspects rather than the adoption-rejection dichotomy [17, 24, 25]. However, it is an important question (especially for stakeholders) how likely users are to continue using an app with a particular task and purpose – for example, whether people using a PA app for a pastime would be more likely to continue using the app for lifestyle management. Most appropriation process studies rely on qualitative or cross-sectional analysis. Longitudinal evidence is required to establish the predictive value of the aspects of use listed in the MPA model.
Another notable gap in the research is that studies on adoption and appropriation focus almost exclusively on IT use (or use intention) of information technology as the dependent variable. Analyses of these proximate outcomes are meaningful for designing and updating service products. However, when it comes to a healthcare app, distal outcomes are equally important; that is, how the functional and symbolic aspects of app use are associated with actual health outcomes such as engagement in PA and exercise (in the case of apps supporting PA and exercise).
Objectives
Therefore, the current study investigated how the functional and symbolic aspects of PA-app use would predict the (a) (dis) continued use of apps and (b) changes in PA levels over time. Questionnaire data from a longitudinal survey were analyzed. Participants reported how they used a PA app (for the functional and symbolic aspects) at baseline, and at the six-month follow-up, they completed a questionnaire regarding the current use (vs. non-use) of the app as well as their levels of PA.
Our analyses were conducted in a somewhat explorative manner, as we did not have a clear a priori hypothesis regarding which aspects of app use would be predictive of its continued use and participants’ PA levels at follow-up. However, the stage model of Benamar et al. [28], conceptualizing appropriation as a dynamic process of four stages (i.e., symbolic appropriation, exploration, use construction, and stabilization), may hint at how different app use patterns predict continuation. In the symbolic stage, users encounter a new app (a smartwatch in the analyses by Benamar et al. [28]) and imagine what they will do after its acquisition. Users then experience the app in terms of its sensory aspects and potential (the exploration stage). Then, users’ interactions with the app become more regular and functionalist by learning the functionality of the app (the use construction stage), implying that users have increased awareness of what they need and what they can do with the app. Simultaneously, they sort which functions to use, and the functions that were not viewed as useful are used less frequently through this sorting process, as those functions are less relevant to achieving a specific objective, such as improving PA. The lifestyle management dimension of the functional aspects of the MPA model is conceptually relevant for the use construction stage, whereas distraction and building relationships are less on purpose and may be deemed less functionalist. The stabilization stage, corresponding to the appropriation state, is characterized by a good knowledge of the app, affective attachment, and identity pertaining to the symbolic aspects of use in the MPA model.
Taken together, the lifestyle management dimension would be predictive of continued app use at the 6-month follow-up, as it may indicate that users are close to (or have already reached) the appropriation state; however, distraction and building relationships may be less predictive, as the sorting process is yet to be triggered. Symbolic aspects, which are thought to be the key characteristics of the appropriation state or stabilization stage, would also be predictive of continued app use at the follow-up.