MoviPill: Improving Medication Compliance for EldersUsing a Mobile Persuasive Social Game

Rodrigo de Oliveira, Mauro Cherubini, and Nuria OliverTelefonica Research

via Augusta 177, 08021, Barcelona – Spain{oliveira, mauro, nuriao}@tid.es

ABSTRACTMedication compliance is a critical component in the suc-cess of any medical treatment. However, only 50% of pa-tients correctly adhere to their prescription regimens. Mobileand ubiquitous technologies have been proposed to tacklethis challenge, mainly in the form of memory aid solutionsthat remind patients to take their pills. However, most ofthese methods do not engage patients in shifting their behav-ior towards better compliance. In this paper, we propose andevaluate a mobile phone-based game called MoviPill thatpersuades patients to be more adherent to their medicationprescription by means of social competition. In a 6-weekuser study conducted with 18 elders, the use of MoviPill im-proved both their compliance to take the daily medicationand also the accuracy of the drug intake time according tothe prescribed time. Moreover, the improvement in the latterincreased from 43% to 56% when we considered only par-ticipants that had any interest in games, which reveals theimportance of applying persuasive techniques in a personal-ized manner. We conclude with a set of implications for thedesign of persuasive mobile solutions in this domain.

Author Keywordspersuasive mobile interfaces, elderly, medication compliance,user study.

ACM Classification KeywordsJ.3 Life and Medical Sciences: [Medical information sys-tems]; H5.2 Information interfaces and presentation: Userinterfaces—Evaluation/methodology

General Termsdesign, experimentation, human factors, verification.

INTRODUCTIONHuman memory is one of the most intriguing cognitive pro-cesses. It dynamically retains the most relevant elements ofour life. At the same time, it is prone to failures. Hence, itis no surprise that the automated capture and access to liveexperiences is considered among the top three main researchthemes in Ubiquitous Computing [4]. Relying on our mem-ory may be a dangerous practice when our health depends onit, as it is the case in medication compliance. A recent review

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of 139 studies reporting compliance data showed that only63% of patients keep complying with their medication after ayear and patients take their medication only 72% of the time[13]. Adherence rates are typically higher among patientswith acute conditions, as compared with those with chronicconditions. Clinical trials report average adherence rates ofonly 43 to 78 percent among patients receiving treatment forchronic conditions [17]. Similar results were obtained in astudy involving 325 elderly (average age of 78 years) [31],whom are frequently taking medication for chronic illnesses.

In order to tackle this challenge, medical experts have trieda variety of approaches that remind patients to take theirmedication. Simple intervention methods such as telephonicfollow-ups by the pharmacist were shown to be effective inenhancing medication compliance [24, 27] and reducing theoverall costs to the health provider [18]. However, this typeof approaches are difficult to sustain in the long-term and ata large scale [32]. With the pervasiveness of mobile phonesand the advent of “smart packages” (e.g., GlowCaps [3]), au-tomated reminding could be addressed to solve the problemof scalability. Still, previous work reports cases in which noimprovement in medication compliance was observed by us-ing reminders alone [23, 25, 38], or even where automatedreminders were perceived negatively by the users [39].

Persuasive techniques could address this problem by shift-ing the focus from a human activity that we are not typicallygood at (i.e., remembering) to an activity that we tend to begood at and enjoy (i.e., socializing). Previous work in thisarea has already shown promising results to obtain positivechanges in people’s behavior in a variety of domains (e.g.,motivate physical activity using personal awareness [22] andsocial competition [11, 16]). However, most of the strate-gies that address medication compliance involve remindingpatients to take their pills and educating them on the effectsof non-compliance, which do not seem to be enough to mo-tivate people to comply with their medication regimens [36].Alerting patients to do the same thing everyday does not en-gage them in actually doing it by themselves.

Our approach towards increasing levels of compliance (re-membering to take a dose) and adherence to medication regi-mens (taking doses at the prescribed time) focuses on chang-ing the way people perceive the drug intake task. Particu-larly, our main hypothesis is that patients become more com-pliant in taking their medications when the task is not seenas an obligation, but rather as an entertaining and engag-ing experience. In this paper, we address engagement bymeans of a game. We have implemented a mobile phoneapplication called MoviPill to encourage compliant behav-ior by giving more points to players that take their medica-

tion very close to or at the prescribed time, and less or nopoints otherwise. The game includes a social competitioncomponent by connecting all players through a social net-work and allowing them to check how disciplined they arein regard to the other competitors. To validate our approach,we have conducted a 6-week user study using a crossoverdesign with 18 elders that considered themselves compliant,did not know each other, and did not receive any monetaryincentive for winning the game. Results confirm our hypoth-esis: both prescription adherence (remembering to take dailydoses) and regimen adherence (taking doses at the prescribedtime) were improved when participants played the game. Tothe best of our knowledge, the work presented in this pa-per is the first approach to look at the challenge of medica-tion compliance from an entertainment and user engagementperspective in the form of an mobile social persuasive appli-cation. Also, the presented system is one of the first thataims at encouraging compliance to recurrent activities thathappen at specific times.

RELATED WORKMedical LiteratureMedication compliance/adherence is typically defined as “theextent to which a patient acts in accordance with the pre-scribed dosing regimen” [13]. Research on this matter hassuggested different strategies to increase the patients’ lev-els of medication compliance, including: (1) counseling, (2)simplified regimen plans, and (3) compliance aids [9].

The counseling strategy focuses on patient education, in-cluding risk factors of non-compliance, information abouttheir illness, instructions on how to take the prescribed med-ication correctly, and explanations of the benefits and possi-ble adverse effects of the therapy. This method has been ex-tensively applied yielding mixed results in different studies.For instance, Russel et al. identified that 21 out of 42 stud-ies on counseling interventions did not reveal any differencebetween treatment and control groups, while the remaining21 studies did [36].

Simplified regimen plans include drug reminder charts [23],calendar packaging [15], and dosage boxes [14]. These stud-ies reveal that this strategy alone is unlikely to improve drugcompliance.

Finally, compliance aid has proven to be one of the most ef-fective strategies to date. For instance, telephone follow-upsby the pharmacist were extensively tested and proven to beeffective in enhancing medication compliance [24, 27] whilealso reducing the overall cost to the health provider [18].However, this intervention method does not scale well for alarge population on a long-term basis [32]. Other success-ful methods include “smart packages”, such as the MEMS[2] and GlowCaps pillboxes [3], which record date and timeevery time they are opened. The GlowCaps pillbox also ad-dresses automated reminding. The main assumption behindthis approach is that when patients are alerted about their noncompliant behavior throughout the day, they will take theappropriate actions to change that behavior. However, thesemethods focus on reminding patients of something they al-ready know they have to do, without engaging them in doingit by themselves.

Combinations of these strategies have been frequently pro-posed in the literature with the assumption that a single ap-proach cannot be effective for all patients. An example is

the use of both counseling strategies and compliance aids totrigger the patients’ motivation towards adherence to medi-cation. Unfortunately, even this combined solution has beenshown to be ineffective in a few cases according to both ob-jective [23, 38] and subjective [25] measures. Another ap-proach – motivated by a recent study reporting that 40% ofadults delayed care or failed to follow prescriptions to savemoney [19] – consists of providing patients with monetaryincentives, which reveals how inefficient reminders can bewhen people are more interested in immediate rewards.

Computer Science LiteratureAccording to Mynatt et al. (2004), “the next revolution oftechnology in the home will arise from technologies aimed athelping older adults maintain their independence and qual-ity of life while helping avoid a transition to a more ex-pensive, institutional setting” [33]. Indeed, the UbiquitousComputing community has been addressing this challengein recent years [26] by proposing that technologies for el-ders should be designed with a systemic approach: keepingin mind the networks of caregivers usually involved with thecare of old people [12], and their social interdependence [8].

Research on persuasive technology draws from psycholog-ical theories such as the goal-setting theory [28] and thetrans-theoretical model [35]. The former describes how in-dividuals respond to different types of goals, while the lat-ter identifies the stages through which an individual pro-gresses to intentionally modifying his/her behavior. Follow-ing these theories, different persuasive health-related appli-cations have been proposed in the literature and have shownpromising results in positively changing people’s behavior.For instance, Franklin et al. [21] demonstrated that by pro-viding text-messaging reminders to diabetes patients theycould improve self-efficacy and adherence to glycemic con-trol. As another example, Mamykina et al. [30] investigatedthe deployment of a prototype of a health-monitoring ap-plication that was designed to offer feedback to individualswith diabetes concerning their blood sugar levels through-out the day. Their study demonstrated positive outcomes ofparticipants interacting with their system, thus revealing thatindividuals need to proactively engage in the investigationof their disease rather than relying only on guidelines. Sim-ilarly, Sashima and Kurumatani [37] proposed a monitoringinfrastructure through which caregivers can keep track of thehealth status of a patient wearing physiological sensors usingmobile phones.

Recently however, the transtheoretical model was criticizedbecause of its over-reliance on intrinsic factors to explainmotivation. The critics argued that extrinsic factors, suchas community influence, might just be as important as self-motivation [5]. Therefore, other researchers focused on de-signing applications for compliance aid that could leveragegroup interactions. Consolvo et al. [11] designed a proto-type mobile application for encouraging physical activity bysharing step counts with friends. They found that partici-pants who shared their step counts were significantly morelikely to meet their goal than participants that did not sharethis information. Similar results were obtained by Fujiki etal. [22], who designed a ubiquitous game application to en-courage physical activity. Data from a wearable accelerom-eter was logged to a cell phone and used to control the an-imation of an avatar that represented the player in a virtualrace game with other players. More related to medicationcompliance is the study of Mamykina and Mynatt [29], who

designed a ubiquitous health monitoring application to facil-itate the discovery and learning from past experiences withina community of patients with diabetes. Finally, Chiu et al.[10] designed a mobile social persuasion system to moti-vate users to drink the right quantities of water during theday. Results suggested that the two hydration games imple-mented by the authors (single/multiple players) were effec-tive for encouraging regular water intake by users. Whilethis work is promising and relevant, it cannot be generalizedto the domain of medication adherence for different reasons,including the fact that while drinking is a biological primaryneed for the human body –regulated by various physiologi-cal reminders, the need to take a medication is in many casesnot signaled by our bodies until it is too late. Moreover, thedrug intake task is a recurrent activity that should happenat specific times in order to provide the body with the ap-propriate quantities of the medication throughout the day, asopposed to the task of drinking water.

RESEARCH QUESTIONSThe primary goal of our proposal is to change the patient’snon-compliant behavior by engaging him/her in the drug in-take task. Taking medication is not typically considered afun activity and we do not claim that our proposal changesthis fact. However, by creating a social game around thisactivity, we expect users to: (1) approach it with additionalcuriosity; (2) find support – and a certain level of entertain-ment – by connecting their medication routines with thoseof other people; (3) increase their interest in the task; and inconsequence (4) improve their medication compliance. Eventhough the prototype presented in this paper could be usedby any demographic group, we have focused our effort onelders: adults of 60 years or older, for whom medicationcompliance is most likely to be a contributing factor to theirquality of life. In particular, the two research questions ad-dressed in this paper are:

RQ1: Can a mobile social persuasive game help elders ad-here to their medication prescription (i.e., take all daily doses)?

RQ2: Can a mobile social persuasive game help elders ad-here to their medication regimen (i.e., take the daily doses atthe prescribed time)?

MOVIPILL PROTOTYPE

ArchitectureMoviPill’s architecture can be explained by the followingscenario, sketched in Figure 1. For illustration purposes, letus consider a user that takes two doses per day of a certainmedication. For the first dose of the day, the user opens thepillbox containing the medication and takes a dose of it (step1 in the figure). On the inner part of the pillbox lid, there isa sensor that registers date and time the pillbox was opened(similar to current technology [2]). When the user opens thepillbox, the data is sent wirelessly to a nearby computing de-vice that runs the MoviPill application –e.g., mobile phone,PC, etc. (step 2). Whenever the device is connected to theInternet, it sends to the MoviPill server the identifiers of boththe user and the medication, and the date and time that thepillbox was opened (medicine supposedly taken; steps 3 and4). On the server side, the user’s information is validated andhis/her drug intake profile is updated in the database (step 5).Finally, the server sends a confirmation back to the comput-ing device (via the Internet), which updates the status of theMoviPill game (steps 6 and 7).

Figure 1. MoviPill’s architecture. Step (2) was not implemented to helpus answer the research questions.

An alternative implementation to the previous scenario wouldenable the pillbox to send the information directly to theserver without the need for the pillbox to be closer to a de-vice running MoviPill at the moment of the drug intake (i.e.,step 2 in Figure 1). This approach would entail extra com-plexity to the pillbox manufacturing and the user would stillneed the internet-enabled device for the game. Hence, weopted for the first alternative in our implementation. In ad-dition and for the purpose of the experiment (see Section“Procedure” for more detail), step 2 was not included in or-der to investigate whether participants would try to cheat inthe game (e.g., confirming the drug intake closer to the pre-scribed time – using the smartphone interface – but actuallyopening the pillbox way later or not opening it at all).

Game DynamicsMoviPill players have a well defined, single goal: to taketheir medication the right number of times per day (pre-scription adherence) and as close as possible to the timeprescribed by their doctor (regimen adherence). The closerto the prescription time, the more points they obtain: (a) twopoints if the intake occurs within ±15min of the prescribedtime; (b) one point if they take their medication within ±15to ±30min of the prescribed time; (c) zero points if within±30min to ± 12

dose regimen hours; and (d) −1 point if theyforget to take their medication. By the end of each week,MoviPill highlights that week’s game winner to all playersand restarts the game for the following week. Figure 2 ex-emplifies the game’s dynamics.

Figure 2. Example of points and emoticon assignments for a patientthat takes two doses per day of a certain medication (8am/pm).

MoviPill aims to achieve positive changes in people’s behav-ior towards medication compliance without depending onreminders. Therefore, the application fires a soft alarm 15minutes after the drug’s prescribed intake time in the casethe user did not take it. Hence, the game players should tryto remember to take their doses by themselves if they reallywant to win the competition. Otherwise, chances are thatother competitors will remember to take their medication atthe right time and thus win more points.

User InterfaceThe MoviPill smartphone interface has been originally de-signed for elders. Therefore special care has been devotedto its layout and interaction design. Buttons and dialogsare personalized with bigger fonts and higher color contrast,while touchscreen interaction is enabled without the need ofusing a pen stylus. The application primes simplicity by of-fering only two different screens: Dose and Game.

The Dose screen displays the date and time the medicationwas taken together with the time of the next intake and aprogress bar informing how much time is left to the nextdose (see Figure 3 left). The interface was designed to mon-itor intakes of a single medication to avoid collateral effectsin our experimental validation. We plan on expanding theinterface to handle multiple medications in the future.

The Game screen displays the status of the game. Special at-tention was dedicated to including social competition with-out violating the players’ privacy. Hence, the data on thisscreen, which was shared with the other players, did not pro-vide any information on the medication that each player wastaking. Moreover, we used emoticons (see the bottom of Fig-ure 2 and Figure 3, right) to represent how compliant partici-pants were on each dose, without revealing the exact time oftaking their medication. A social network was created withall the participants and social competition was implementedby ranking all players according to their score in the compli-ance game (see Figure 3 right).

Figure 3. MoviPill’s user interface: Dose screen on the left, showing thedose intake button that users shall press when they take their medica-tion (a); Game screen on the right, presenting the ranking of players(b). The number of emoticons next to each participant’s score corre-sponds to the number of doses prescribed per day (c). Emoticons rep-resent how compliant players were with that dose (see Figure 2).

Two clinicians were contacted during the design phase. Af-ter trying the system, both of them presented positive feed-back regarding the game dynamics and its persuasivenesstowards increasing levels of medication compliance. Con-versely, they were also concerned that some medications areprescribed to be taken after a meal and therefore the intaketime cannot be fixed. In the initial evaluation of MoviPill,we did not take these cases into consideration.

EXPERIMENT DESIGNGiven that the technology proposed in this study was testedin domestic environments, we opted for a combination ofresearch methods: interviews and a field study. In the 6-week field study, participants interacted with the Dose and

Game versions of the MoviPill application for three weekseach –similar to the experimental design of Chiu et al. [10].The interviews were intertwined with the deployment andhelped to assess the drug compliance habits and the reactionto the introduction of the new technology.

ParticipantsFrom an initial pool of 20 participants, 18 (m: 9, f: 9) com-pleted all steps required during the 6-week user study (twodropped out in the first week due to personal reasons). Themedian and mean age of the recruited participants was 67.5years (s = 4.19, min: 59, max: 75).

Sampling. A randomized sampling methodology was usedand participants were assessed by a Spanish social founda-tion service (FASS) [1]. Participants were interviewed overthe phone to assess their willingness to participate in thetrial. Requirements for being recruited included: (1) being amobile phone user, (2) taking at least one medication twiceper day that (3) does not require to be taken after a meal.Cognitive decline was not measured and therefore the ran-domized sampling shall have selected subjects with differ-ent levels of age-related diseases (in order to prevent a con-founding effect from this decision, we opted for a crossoverdesign, as described in Section “Procedure”). Participants re-ceived 40 Euro (about 59 USD) for their participation in theexperiment and they did not receive any monetary incentivefor winning the weekly competitions of the MoviPill game.

Social life. All the participants were retired. Thirty-ninepercent lived with a husband or spouse, while the rest livedalone. The participants had a median of 3 siblings. Ten par-ticipants (55%) did not have any experience with computers,while 4 (22%) had an intermediary knowledge, and the re-maining 4 (22%) were advanced users. The majority of thesubjects used to go out for shopping and entertainment a fewtimes per week. The subjects did not know each other.

Medication compliance. The majority of the participants (12or 67%) reported that they did not typically forget to taketheir medications; four participants (22%) forgot rarely, and2 participants (11%) forgot sometimes. Only 2 participants(11%) reported being frequently unsure of whether they hadalready taken their medication or not, 7 participants (39%)reported forgetting sometimes and the remaining 9 partici-pants (50%) reported never forgetting. Concerning the strat-egy that participants used to remember to take their medica-tions, 3 participants (17%) reported using some form of spa-tial arrangements of the pillboxes, while the majority (14 or78%) remembered because of their daily routines. Only oneparticipant (5%) declared taking advantage of family mem-bers to remember to take her medications.

Technology in the household. All participants had a land-line in their home and owned a mobile phone. Their use ofthe mobile was basic: they use it to be in contact with fam-ily members when running errands and for emergency situ-ations. Ten participants (or 55%) did not have a computerin their house, and therefore defined themselves as being in-experienced with computers. The remaining 8 participantshad a PC or laptop in their premises: 4 (or 22%) definedthemselves as “beginners”, while the remaining 4 definedthemselves as “intermediate” users.

ApparatusEach participant was assigned a HTC smartphone (model P3300,with its charger) with the MoviPill application and a pillbox

equipped with a sensor (maker AARDEX model MEMS 6 [2]).The smartphone was able to transmit data over the GSM cel-lular network. Medication intake information was enteredby participants via the Dose interface (previously explained)in the MoviPill application –running on the mobile device–and transmitted in real time to the remote server. When-ever the Internet connection was lost, MoviPill kept a lo-cal log of the drug intake and attempted to re-establish theconnection every 10 seconds. When one of these attemptssucceeded, MoviPill would send the previously saved drugintake data to the server. In addition, MoviPill refreshed thegame status every 5 minutes in order to ensure that the datapresented was up-to-date. The battery life allowed the userto keep his/her phone unplugged for several hours. The pill-box recorded the intake information independently from thephone and these logs were used as an independent measureof medication compliance as explained in the next section.Figure 4 presents a typical setup of the apparatus.

Figure 4. A typical setup of the apparatus (subject 15): (a) HTC P3300smartphone running MoviPill; (b) MEMS pillbox containing the med-ication of the participant, the label on the box reported the regimeninformation; (c) other medications that were not part of the study; (d)instructions guide of MoviPill; (e) charger of the participant’s mainphone; (f) charger of the smartphone.

ProcedureWe met participants at the beginning of August 2009 for thedeployment. We scheduled a face to face meeting in eachof the subject’s home to conduct the initial interview, deliverthe apparatus and train the subjects on using MoviPill. Dur-ing the initial meeting, we explained the mechanics of thegame, supervised each participant during the initial interac-tions with the application, and helped participants transfertheir medication into the MEMS pillbox. For this study, weasked them to choose one – not life threatening, e.g., pre-scribed for pain, attention, etc. – medication that they hadto take twice per day so that each participant had the samechances of winning points. We explained to the participantsthat they had to continue taking their other medications usingtheir usual routines. Furthermore, we personalized MoviPillwith a digital portrait of each user and entered the name ofthe medication that they were taking (see Figure 3) and thecorrect regimen information. We left their home once wefelt that each subject was confident enough to operate theapplication alone and understood all the aspects of the ex-periment. MoviPill was disabled in all the phones and wasonly automatically initialized at midnight of the first weekof the user study.

Two intervention methods were evaluated in the 6-week userstudy: Button and Game. On the Button treatment, subjectsused the smartphone to register each drug intake by pressing

a single button on the screen (equivalent to the button shownin Figure 3 left, but on a blank screen). In this treatment, par-ticipants had to trust their own methods to remember when totake their medication. In the Game treatment, subjects alsoused the smartphone to register each drug intake (see Fig-ure 3 left), but they also had a “Game” button on the screenthat allowed them to view the weekly ranking – by compli-ance – of all the participants in the game and their daily drugintake status. In this treatment, the application also played areminder alarm 15 minutes after the set intake time for eachdose and only in the case that the participant did not takethat dose, i.e., didn’t press the drug intake button (see Sec-tion “Game Dynamics” for the reasons why we opted for thedelayed alarm in MoviPill). In case the participant did nottouch the device, the alarm stopped automatically 30 min-utes after the set intake time (i.e., the alarm would only playcontinuously for 15 minutes if no action was taken). Theeffects of this alarm in the Game treatment are presented inthe “Results and Discussion” section.

The Button treatment was used instead of a control group(e.g., electronic pillbox without the phone) because we wantedto guarantee that any experimental difference in compliancewas due to the presence of the game, and not simply becauseof introducing new technology to the participants’ day-to-day life. Similarly, we disabled the wireless connection be-tween the electronic pillbox and the smartphone and we re-quested participants to press the drug intake button on thesmartphone screen every time they took a dose because wewanted to allow game cheating. Furthermore, this cheatingcapability was not “advertised” to the participants to guar-antee that if they would cheat, it was because they figured itout how to do so and decided to do it.

Given the size and nature of our sample, we decided to con-duct a crossover experimental design to eliminate individualdifferences from the overall treatment effect, thus enhancingthe statistical power of the results. Therefore, our samplewas randomly divided in two groups of nine subjects, andeach group was submitted to one of the treatments in thefirst three weeks (i.e., users 1-9: Game; users 10-18: Button)and to the other treatment in the remaining three weeks (i.e.,users 1-9: Button; users 10-18: Game). We balanced thenumber of female participants in each experimental group.

At the end of the third week, i.e. during the crossing of theexperimental modality of the two groups, a telephonic ques-tionnaire was deployed to the participants in order to collecttheir self-reported impressions of how the application helpedthem remember to take their medications. A similar set ofquestions was asked at the end of the experiment.

In order to ease comparison with previous work in the liter-ature [36], we opted for measuring medication complianceusing the data collected by the electronic pillboxes instead ofthe data collected by the MoviPill application. Actually, thisis a standard non-invasive compliance measurement widelyaccepted in the literature [17]. However, four participants(users 1, 13, 15, and 17) opened the pillbox only once perday to extract the exact number of pills for the day and or-ganize them with their additional medication. Furthermore,during the individual interviews conducted after the experi-ment, we noticed that users 11 and 14 did not use the pillboxwhen they had to go out, but only the smartphone: “The pill-box is too big. Sometimes, I wanted to go out for a coupleof hours and bring the system with me, but the pillbox was

somewhat obtrusive.” (participant 14). Hence, we used thedata collected by MoviPill instead of the pillboxes only forthese six users. We believe that this was an appropriate deci-sion in order to comply with prior standards while also con-sidering the subjects’ most accurate drug intake time data.

Observed VariablesOne independent variable –Intervention Method– was usedto investigate the effects of the proposed social persuasivegame to medication compliance, named treatments Buttonand Game. The most important dependent variables are de-scribed in Table 1.

Table 1. Main dependent variables logged by the MoviPill application

Variable [Type∗] DescriptionDrug intake delay [I] How early/late –in seconds– each subject

opened the electronic pillbox to take his/hermedication every day according to the pre-scribed time.

Game access rate [I] Number of times each subject pressed thegame button when submitted to the Gametreatment divided by the number of days.

Entertainment level [O] How entertaining subjects thought it wasto use the phone in treatments Button andGame (1: very boring; 5: very entertaining).

Ease of use [O] Subjective measure of how easy subjectsthought it was to use the phone in treatmentsButton and Game (1: very difficult; 5: veryeasy).

Win effort [D] Subjects’ attempt to win the game(Yes/No).

Social curiosity [D] Subjects’ interest in getting to know moreabout the competitors in the game (Yes/No).

Game interest [D] Subjects’ interest in playing the game afterthe end of the experiment (Yes/No).

Subjective prescriptionadherence improvement

[D] Subjects’ perception of the treatments’ in-fluence (Button vs. Game) to help them re-member to take their medication (Yes/No).

Subjective regimen ad-herence improvement

[D] Subjects’ perception of the treatments’ in-fluence (Button vs. Game) to help them re-member to take their medication at the pre-scribed time (Yes/No).

∗ I: interval; O: ordinal; D: dichotomous.

Statistical AnalysisA nonparametric analysis was conducted because most con-tinuous variables did not follow the normal distribution and,when they did, their variances were not homogenous. Asso-ciations between dichotomous variables were assessed usingthe Chi-square test and correlations between ordinal/intervalvariables were assessed using the Spearman’s Rho test. Giventhat a crossover design was conducted, drug intake delaysand prescription adherence could be paired by treatment anda Wilcoxon signed rank sum test was used to check differ-ences between treatments’ distributions. Similarly, subjec-tive drug intake delay improvement and subjective prescrip-tion adherence improvement could be paired by treatmentand a McNemar test was performed. The McNemar testwas also used to verify differences between number of dosestaken within the alarm zone (15 to 30 minutes after the pre-scribed time) paired by treatment. The level of significancewas taken as p < .05. These decisions follow standardiza-tion methods proposed in the literature [34].

RESULTS AND DISCUSSIONThis section discuss the main results obtained with the ex-periment that address the research questions previously stated.First, we present a few interesting findings that are relevantto interpret the main results, followed by those that con-tribute to the evaluation of our hypothesis.

The older the participants were, the more non-compliantthey were; but not when using the game. Although thestandard deviation of age was rather small (s = 4.19), welooked for a correlation between the age and median drugintake delay variables. However, such a correlation couldnot be verified in neither the Game (N = 18, ρ = .039, p =.879) nor the Button (ρ = .05, p = .844) treatments. Onthe other hand, a strong negative correlation was identifiedbetween the age and prescription adherence variables whensubmitted to the Button treatment (ρ = −.552, p = .018).This could be an evidence that the older the subject was, theharder it was for him/her to remember to take the medica-tion. Conversely, when participants were playing the gamethis correlation was not significant (ρ = −.077, p = .761),which could indicate that MoviPill alleviated age-related mem-ory issues.

Prescribed drug intake time did not directly influencemedication compliance. One could argue that doses thattook place very early or very late in the day may have lead todifferent levels of compliance. However, no correlation be-tween the prescribed drug intake time and the median drugintake delay variables could be identified (N = 18, ρ =−.160, p = .525 in Game; ρ = .154, p = .541 in Button).Similarly, the prescribed drug intake time was not correlatedwith the participants’ prescription adherence in either treat-ment (ρ = −.128, p = .612 in Button; ρ = −.365, p =.137 in Game). These results could reflect that shifts in theprescribed time of drug intake are caused by the patient’slifestyle and do not contribute to different levels of medica-tion adherence.

Playing the game was as easy as pressing the button. Nosignificant difference was found between ease of use in theButton and Game treatments (Button: x = 5, iqr = 1, Game:x = 4.5, iqr = 1; N = 18, Z = −1.823, p = .068). Ad-ditionally, ease of use seemed to be closely related to theperceived level of entertainment (Button: x = 4, iqr = 0,Game: x = 4, iqr = 1.75), given that these variables re-vealed a strong positive correlation (ρ = .554, p = .017).This observation is consistent with the main principles of us-ability, as users tend to lose interest in applications they donot understand how to use. Moreover, the application’s easeof use and access increased MoviPill’s persuasive potentialaccording to Fogg’s principles of convenience and mobilesimplicity [20]. Note that our sample includes only subjectsthat had a personal mobile phone and therefore the perceivedease of use could have been lower if we had considered el-ders with no experience with mobile phones.

The participants’ intention to win the game and the num-ber of times they pressed the Game button were two goodindicators of whether they enjoyed playing it. A strongcorrelation was found between the win effort and entertain-ment level variables (N = 18, ρ = .808, p < .001), and be-tween game access rate and entertainment level (ρ = .658, p =.003). Furthermore, game access rate and self reported in-tention to win the competition revealed a strong positive cor-relation (ρ = .561, p = .015), which is indicative of a goodconnection between the participants’ opinions and their ac-tual behavior during the experiment. These results point toan expected user behavior: the more one likes a game, themore attention (s)he devotes to it.

Social competition was present, but not peer competition.Only two participants (11%) thought they might know some-

one in the competition while the remaining 16 participantswere certain that they did not know any of the competitors.Nonetheless, 10 participants (56%) reported trying to winthe game, which shows that despite not knowing the com-petitors, they were still engaged in being the best player.

Validation of RQ1Can a mobile social persuasive game help elders adhere totheir medication prescription?Before the experiment, participants considered themselvescompliant with their medication prescription. Results con-firm they were. From a total of 1512 doses over the 6 weekperiod, only 15 doses were not taken in the Button treat-ment (1%). However, when participants were playing thegame, this small level of non-compliance was reduced by60% (six missing doses). Moreover, only one out of 18subjects was more compliant when submitted to the Buttontreatment than to the Game treatment, which is a good in-dicator of why a significant difference could be found be-tween the medians of prescription adherence in both treat-ments (N = 18, Z = −2.263, p = .024). As expected, par-ticipants could not clearly perceive this subtle difference intheir compliance behavior, and therefore no difference couldbe found on subjective prescription adherence improvementin the Game and Button treatments (N = 18, p = .219).Still, the number of subjects that noticed an improvement intheir compliance behavior was much stronger in the Gamethan in the Button treatment (seven vs. three). It is reasonableto assume that samples with non-compliant patients mighthighlight this difference even more. From these results, wecorroborate RQ1.

Validation of RQ2Can a mobile social persuasive game help elders adhere totheir medication regimen?Participants were highly adherent to regimen as well, takingtheir medication with a shift of ±25 minutes on average ofthe prescribed drug intake time (x = 1471s in Button; x =731s in Game). Due to the presence of outliers, the mediandrug intake delay better characterizes the data, revealing a43% improvement when participants played the game (x =240s vs. x = 420s; N = 720, Z = −8.944, p < .001).Figure 5 compares median and average drug intake delaysover time for each treatment.

Figure 5. Comparison of median and average drug intake delays overtime in the Game and Button treatments.

Although a 43% improvement in regimen adherence is a sig-nificant result, we were interested in understanding the roleof personal preferences on the results. In the last question-naire, participants were given a list of possible rewards formedication compliance (i.e., monetary incentives/discounts,

family photo, favorite song, or playing a game). Seven par-ticipants considered games to be the least interesting reward(users 4, 7, 8, 9, 12, 15 and 17). The improvement in regi-men adherence in the Game treatment for the rest of partici-pants – excluding the seven that were not interested in games– was of 56% (x = 180s vs. x = 405s; N = 437, Z =−10.068, p < .001). This finding reveals the importanceof applying persuasive technologies according to the user’sprofile and context.

Another way to analyze this data is to consider each partic-ipant’s median drug intake time as a single output and com-pare the median of the medians between treatments. Again,a significant difference could be found between regimen ad-herence in the Game and Button treatments (N = 18, Z =−2.250, p = .024). This last analysis proves that improve-ment in regimen adherence could be observed for most ofthe users. Therefore, we corroborate RQ2.

Reminders vs. Social CompetitionPrevious work has already reported the effects of using re-minders (e.g., an acoustic alarm played after a time interval)to improve medication compliance [23, 25, 38, 39]. Particu-larly, Chiu et al. investigated the effects of reminders as partof a game experience [10], although not in the medicationadherence domain. Next, we discuss the effects of introduc-ing the 15-minute delayed alarm in the Game treatment butnot in the Button treatment, and the consequences to the RQ1and RQ2 validations presented before.

Impact on regimen adherence (remembering to take dosesat the prescribed time). From the 750 doses taken by the 18subjects when submitted to the Game treatment, 73 (10%)doses were taken during the time that the alarm was play-ing (alarm zone) while the remaining 677 (90%) doses weretaken without any alarm being played. Interestingly, in thesame alarm zone but in the Button treatment (when actuallyno alarm was played), more doses were taken: 91 out of 741doses (12%). Anyway, this apparent difference was not sig-nificant (N = 634, χ = .764, p = .382), which confirmsthat the reminder had no effect on the subjects regimen ad-herence, and hence, supports the validation of RQ2.

Impact on prescription adherence (remembering to takeall doses). We acknowledge that no strong conclusions canbe drawn here by just looking at the quantitative results thatwe have. However, six subjects (33%) reported in the ques-tionnaire that the alarm reminded them only once or twiceto take the medication and the remaining 12 subjects (66%)answered that the alarm never helped them. These findingspoint to the conclusion that RQ1 is also valid, but we plan toinvestigate the potential impact of the reminder on adherencein future work.

Shortcomings of the studyOur experiment lacks a third treatment in which only systemreminders would be present, thus allowing the comparisonbetween game and reminders alone. We did not focus onthis comparison as previous work has already concluded thatusers can perceive system reminders negatively [39].

Also, the participants recruited for the study happened to beextremely disciplined in taking their medications. Yet, wecould measure an improvement in their regimen adherence.Previous work confirms that elders tend to consider them-selves compliant when first asked, but after the study they

realize that they are not [25]. Therefore, it is yet unknownhow to recruit non-compliant elders if not by selecting themat random and expecting a certain average of non-compliantelders in the sample. We recruited our participants follow-ing this standard procedure through a social service founda-tion (FASS) that had more than 100,000 elders subscribedin the state of Andalucia - Spain. Indeed, it was only afterthe study that we realized that the elders were very compli-ant. Nonetheless, we would like to emphasize that the pur-pose of the study was to investigate whether social compe-tition can improve medication compliance when comparedto usual care, which was actually the case. We expect lon-gitudinal studies conducted with samples from different re-gions/cultures to better exemplify such an improvement.

SummaryThe validation of both research questions RQ1 and RQ2 con-firms that social competition is an effective tool to improveboth prescription and regimen adherence of independent el-ders living in a non-shared environment. Although we can-not directly extrapolate these results to peer competition ap-plied in shared housing – another usual living setting for el-ders, we expect the observed positive effects of competitionbetween strangers to be extended to friends, as long as theusers involved have an interest to play with people they arefamiliar with. Furthermore, the results presented in this pa-per add to prior work, e.g., the study on daily water intakeconducted by Chiu et al. [10]. Our findings reveal that theusers’ intake behavior can be improved by means of a socialgame, even for an activity that is not biologically regulatedby the human body (i.e., taking medicines). This strategyalso proved to be useful for regimen adherence (i.e., a rou-tine activity that happens at specific times), a dimension notevaluated in previous work on persuasive technologies.

IMPLICATIONS FOR DESIGNThe findings presented in this paper combined with qualita-tive research conducted in situ support a number of guide-lines that might serve designers in better addressing com-puting challenges for elders. Next, we highlight the mostrelevant ones:

Different elders, different disabilities: The power of mul-timodal interaction. Even after our first pilot meeting withelders from an independent living community, we could nothave predicted the range of motor and cognitive disabilitiesthat we would face in the user study. For instance, two par-ticipants had strong vision impairments – one used a magni-fying glass to read, but they were very precise when pressingthe phone’s buttons. Conversely, other participants had goodvision, but their hands trembled when touching the phone’sscreen, thus leading to poor precision. In some cases, el-ders slid their finger outside the button area while pressing abutton, thus involuntarily preventing the system to catch thisevent. Hence, we recommend using multimodal interaction(both input and output) when designing applications for theelderly, e.g., combining two different sounds (event executedvs. not executed) with high visual contrast between button’sstates (up and down).

Use Walk-through and Think Aloud to catch low visibil-ity of alternative task flows. It is well known that HCIresearchers should never assume that users have the basicknowledge to interact with any given interface, as it is il-lustrated by an interesting phenomenon that we encounteredin our study. During the deployment of the study, when we

asked participants how they knew there were more than fourcompetitors in the game by just looking at the players list,some never mentioned the scrollbar. For them, the visualclue was that the fourth player was partially revealed, thusindicating more content (see Figure 3). This simple factled us to realize that the common method of teaching firstand asking later prevents the detection of misconceptionsbetween the application’s conceptual model and the user’smental model. Actually, the inverse of the method seemsquite more interesting, specially in the early stages of pro-totyping. Indeed, the use of Walk-through and Think Aloudtechniques proved to be efficient in our study. These meth-ods revealed what the elders understood about the interfaceobjects and how they used them to accomplish the tasks. Af-ter presenting the elders some alternative paths to solve thesame task and observing them later on (e.g., checking logs,questions in interviews/questionnaires), it was easier to iden-tify what was their preference between different task flows.

Bigger fonts and more explanatory texts are not neces-sarily better: Consistency plays an important role. Gen-erally, the size of texts, buttons and other interface elementsshould be increased when designing applications for olderusers. Also, tasks are usually described in a more verboseway to ease their comprehension. However, we noticed acase where external consistency was more important. Dur-ing our first visit to the elders, some of them could not per-ceive the drug intake button on the center of the phone screen(see left screen in Figure 3). After they were told the biggreen button on the center of the screen with an explanatorysentence on it was the button we were referring to, the typi-cal answer was: “Oh! So this is a button?” Conversely, thisreaction never occurred when we asked participants to pressthe game and the dose buttons on the top of the screen, whichare about one fourth of the size and with a single descriptivekeyword on it. This experience reinforced our convictionregarding the importance of matching external consistencywith the elders’ expectations.

Elders do engage in competitions: Prevent game cheat-ing. In the first visit to participants, two of them mentionedthe possibility of pressing the drug intake button on the phoneat the appropriate time while taking the pill later on just toget more points. Indeed, this pattern could be observed in theexperiment: seven subjects had at least once opened the pill-box more than one hour after they had actually pressed thebutton on the phone. This reveals how engaged elders wereto win the game. Furthermore, from the responses obtainedwith the final questionnaire, we noticed that caregivers hadalso an impact on competition engagement: “I was tryingto win the game to look good to my grand-daughter. Actu-ally, there was one night when she reminded me to take mymedication because I was playing the game.” (participant17). Therefore, cheating prevention is of major importancein the success of game-based applications, even when theyhave been designed specifically for the elderly.

Know your audience: Choosing the “right” competitorsmotivates the elders. After analyzing the answers of thefinal questionnaire, we observed that the participants’ inter-est to win the game was associated to the players they werecompeting against. We interpret the strong association iden-tified between these variables (N = 17, φ = .528, p = .03)as follows: subjects were engaged to win the competitionwhen they had a preference to play against unknown people,as it was the case in the study.

Different rewards for different users. Personalization iskey not just to address different age-related problems, butalso to understand distinct profiles and choose the most ad-equate persuasive technique accordingly. In the last ques-tionnaire, participants ranked a list of four symbolic rewardsfor good medication compliance behavior: earning points towin a game, accumulating points to get discounts in storesor their phone bill, being surprised with a photo from a fam-ily member (e.g., grandson), or hearing one of their favoritesongs. Surprisingly, the game related reward was listed lastby 7 out of 17 participants that ranked the list of rewards(41%). As shown before, when these participants were re-moved from the data analysis, the improvement in regimenadherence increased from 43% to 56%, thus highlighting theimportance of creating persuasive applications with multi-ple persuasive techniques to better address individual prefer-ences. After analyzing the rankings provided by the partici-pants, there was no significant difference between the game-photo, game-song and photo-song pairs. Interestingly, mon-etary incentives were the preferred reward when comparedto all the others, being the first choice of 13 subjects out of18 (72%). This is in accordance with a recent report aboutthe main reason for non-compliance [19] and in discordancewith latest findings in behavioral economy where monetaryincentives have been shown to impair performance [6]. Weplan to investigate the actual impact of different persuasivetechniques, and their related incentive schemes, when com-pared to their expected impact as reported by participants.

Involve caregivers and family members in the study asextra supportive observers. HCI experts should approachelders and caregivers at the same time during field studies forat least two important reasons. Firstly, if the elder doesn’tlive alone, (s)he is not the only user of the healthcare sys-tem. Others might eventually have to interact with it, even ifindirectly. Secondly, an extra observer in situ can provide in-valuable qualitative feedback during and after the study, suchas in the following example: “He was already used to tak-ing his medication regularly, but the game got him excited.Besides, he was the winner in the first week!” (a femalecaregiver talking about her husband: participant 2). Further-more, some caregivers called us when the elder was unsureabout something related to the application. It is very im-portant though to make sure caregivers understand that theirrole in the study is to only observe and never interfere on theelder’s interaction with the system.

Privacy is key, but elders seem open to share personalinformation when it’s reciprocal. Indeed, one of the prin-ciples of ethics in persuasive computing is that persuasivetechnologies revealing personal information about a user toa third party should be closely scrutinized for privacy con-cerns [7]. In our experiment, subjects rated in a 5-point Lik-ert scale how comfortable they were with other participantsknowing if they were adherent to their medication. Resultsrevealed that they felt comfortable with that (x = 4, iqr =1). Particularly, one participant mentioned that she saw noproblem with this because the information sharing was re-ciprocal: “I am comfortable with that. Everybody is sharingthe same information as well.” (user 13). Nonetheless andfor ethical reasons, we also made sure that everyone in theelders’ household knew about the project and that the elderscould leave the experiment anytime they wished to do so.

Consider the ecology in which technology will be deployed.During the field trial of MoviPill, we realized how the tech-

nology we introduced in the elderly’s places was disruptingthe practices they were used to. In one case, one of the sub-jects was sporadically using a clock before the deploymentto remind himself to take a certain pill. During the deploy-ment, he used the clock systematically to remember whento press the competition button (so to maximize the num-ber of points). As another example, one of the elders wasmoving from right to left the boxes containing the differentdrugs that were inside a cabinet to remember whether shetook them or not. As one of the drugs was used for the ex-periment, she moved it outside the cabinet and used MoviPillto check whether she had already taken that particular medi-cation, thus mixing strategies. In short, each new technologyis going to compete with other existing technologies alreadyin use in a certain environment. Users might adapt, replace,and create practices around the new technology, but alwaysin relation to pre-existing routines.

CONCLUSIONS AND FUTURE WORKIn this paper, we have proposed and implemented a mobilephone-based social game called MoviPill that engages usersto be more compliant in taking their daily medication. Re-sults from a 6-week user study with 18 elders reveal thatplaying the game improved both compliance in remember-ing to take daily doses and accuracy in the drug intake timeaccording to the prescribed time. With respect to the lat-ter, the improvement was even higher when considering datafrom only those participants that had any interest in games,which reveals the importance of applying personalized per-suasive technologies according to the user’s profile and con-text. Another interesting finding was that a strong negativecorrelation between age and regimen adherence was not sig-nificant anymore when elders played the game, which couldbe an evidence that MoviPill helped alleviate age-relatedmemory issues. The qualitative research conducted in situalso revealed a number of findings that are relevant in the de-sign of mobile healthcare applications for the elderly, such asthe importance of: providing multimodal interaction, match-ing external consistency with the elders’ expectations, apply-ing Walk-through and Think Aloud techniques to catch alter-native task flows, involving caregivers in the user studies asextra observers, and identifying/controlling the key aspectsthat would make a game more persuasive. Future work willexplore other types of persuasive techniques for elders in amobile computing environment.

AcknowledgmentsWe would like to thank the FASS staff [1] and the e-HealthTelefonica I+D Granada. Telefonica Research participatesin the Torres Quevedo subprogram (MICINN), cofinancedby the European Social Fund, for researchers recruitment.

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