Table 1.

Full paper details and quality of evidence ratings.

Publication	Design	Modality	Domain	Impact	Data analysis	gamification element	Sample size and characteristics	Summary	Rating
Ahtinen et al. (2013)	Single group, month-long field study of ‘Oiva’ tool. Usage acceptance and usefulness of tool measured using interviews and questionnaires. No comparison of gamification to non-gamification.	Mobile phone (android)	Mental health: acceptance and commitment therapy	Behaviour (use of tool) - neutral (no point of comparison). User experience (gamification) — negative effect. Cognition (stress, satisfaction with life) - positive effect. Cognition (psychological flexibility) — no effect.	Qualitative content analysis categorised in 3 themes.	Rewards (virtual roses). Progress (paths).	15: 9 females, Working age.	An ACT (acceptance commitment therapy) — informed mobile app was designed to support learning of wellness skills through ACT-based daily exercises. Progress in the program is presented through various encouraging paths, such as change of color after a number of exercises is completed and a reward of a virtual rose, graphical feedback on progress is given immediately. Although wellness improved, the gamification elements were considered not suitable in the context of wellness and mindfulness. Skepticism towards gamification was expressed by 60%. Rewards were not deemed to sit well with mental wellness and mindfulness.	6.5
Allam et al. (2015)	Random allocation to 1 of 5 conditions (1. control; 2. information section access only; 3. social support only; 4. gamification only; 5. social support & gamification). Outcomes measured using questionnaires.	Website	Physical health: activity, health care utilization, and medication overuse. Mental health: empowerment and knowledge	Behaviour (physical activity, health care utilization) - positive effect of social support & gamification. Cognition (empowerment) — positive effect of social support & gamification. Knowledge (of rheumatoid arthritis) — neutral.	Multilevel linear modeling technique. Time — 3 measurement occasions (1st level), patient (2nd level).	Rewards (points, badges, medals). Leaderboard.	157: Rheumatoid Arthritis patients	Study was designed to look into the effects of a Web-based intervention that included online social support features and gamification on physical activity, health care utilization, medication overuse, empowerment, and Rheumatoid Arthritis (RA) knowledge of RA patients. The effect of gamification on website use was also investigated. A 5-arm parallel randomized controlled trial was conducted. The Web-based intervention had a positive impact (more desirable outcomes) on intervention groups compared to the control group. Social support sections on the website decreased health care utilization and medication overuse and increased empowerment. Gamification alone or with social support increased physical activity and empowerment and decreased health care utilization. Gamified experience increased meaningful website access.	15
Boendermaker et al. (2015)	Two studies: Study 1 — compares four versions of the tool (1. original training, 2. neutral placebo training, 3. gamified, 4. social and gamified).	Study 1 — website. Study 2 — website and mobile	Mental health: Substance use (alcohol)	Study 1.	Repeated measures ANOVAs.	Backstory. Avatar. Social Interaction.	Study 1: 77: 38 females, (18–29 years), Study 2: 64: 39 females, (18–35 years), University students, who regularly drink alcohol.	Study 1 focused on a social and non–social gamified version of an Alcohol/No-Go training, aimed at altering positive associations with alcohol in memory. Study 2 compared a mobile to a stationary computer version of the alcohol approach bias retraining. Results indicate that adding (social) game elements can increase fun and motivation to train using CBM. The social gamified tool improved aspects of the user experience and increased motivation to train. The mobile training appeared to increase motivation to train, but this effect disappeared after controlling for baseline motivation to train.	13
	Study 2 — compares mobile and computer-based interventions.			Cognition (motivation to use tool) — positive effect of social gamified. User experience (ease of use) — gamified less easy to use than non-gamified; gamified easier to use than social gamified. User experience (immersion) — social gamified more immersive than original. User experience (task demand) — gamified more demanding than non-gamified. Behaviour (drinking behaviour) — neutral.
	Outcomes measured using questionnaires.			Study 2.
				No relevant differences.
Cafazzo et al. (2012)	Single group, repeated-measures (prior to using tool cf. while using tool). Outcome is number of times blood glucose readings performed. No comparison of gamification to non-gamification.	Mobile phone (iOS)	Physical health: blood glucose monitoring (diabetes)	Behaviour (blood glucose monitoring) — positive effect. User Experience (satisfaction with tool) — positive. Cognition (self-care, family responsibilities, quality of life) — neutral.	not stated (comparison of means)	Rewards (points). Levels.	20 adolescents (12–16 years)	A 12-week evaluation study of use of a mobile app that aims at increasing the frequency of daily blood glucose measurement. Blood glucose trend analysis was provided with immediate prompting of the participant to suggest both the cause and remedy of the adverse trend. The pilot evaluation showed that the daily average frequency of blood glucose measurement increased 50% (from 2.4 to 3.6 per day, P = 0.006, n = 12). A total of 161 rewards (average of 8 rewards each) were distributed to participants. Satisfaction was high, with 88% (14/16 participants) stating that they would continue to use the system. Improvements were found in the frequency of blood glucose monitoring in adolescents when using the gamified tool in comparison to not using the gamified tool.	8.5
Chen and Pu (2014)	Comparison of control (no use of tool) with 3 versions of a gamified tool (1. competition, 2. cooperation, 3. hybrid). Outcomes were physical activity (from fitbit), interviews, diary entries and number of messages exchanged. No comparison of gamification to non-gamification.	Mobile phone (android)	Physical health: activity	Behaviour (number of steps) - positive effect of gamified tool (additionally; cooperative and hybrid more steps than competition).	t-tests supplemented with qualitative analysis of diaries and interviews	Rewards (badges, points). Leaderboard.	36: (18 dyads) 17 females, (20–30 years)	Study evaluates HealthyTogether, a mobile game designed to encourage physical activity. Three versions of the game (competition, cooperation, hybrid) were compared in dyads. Participants could send each other messages and earn badges. Users showed a significant increase in physical activity in both the cooperation (by up to 21.1%) and the hybrid setting (by up to 18.2%), but not in the competition setting (by up to 8.8%). In addition the amount of physical activity was found to be correlated with the number of messages sent.	10.5
Dennis and O'Toole (2014)	Between-groups; placebo training (short + long) vs. gamified training conditions (short + long). Outcomes measures via questionnaires.	Mobile (iOS)	Mental health: anxiety/stress	Affect (anxiety and depression) - positive effect of gamified training (greater positive effect with longer compared to shorter gamified training)	ANCOVAs	Rewards (points). Avatar.	38: Long training condition 27 females (mean age 22) 38: Short training condition 28 females (mean age 20 years). Highly trait-anxious adults, psych. Students.	Study examined effects of a gamified Attention-bias modification training (ABMT) mobile application in highly trait-anxious participants. A single session of the active training relative to the placebo training reduced subjective anxiety and observed stress reactivity. The long (45 min), but not the short (25 min) active training condition reduced the core cognitive process implicated in ABMT (threat bias).	10.5
Hall et al., 2013	User evaluation of tool. Usage rates and self-report questionnaires of user experience and wellbeing recorded from users of the tool. No comparison of gamification to non-gamification.	Website (facebook)	Mental health: well-being	Behaviour (answering survey questions) - positive. User experience (rating of tool) - positive.	correlational analysis, analysis method for user experience unstated.	Rewards (points, stars, badges). Social interaction.	121: 37 females	The study evaluates a Gamified Facebook application for the measurement of well-being. A measurement framework for assessing (human) well-being with a much higher observation frequency (e.g. daily) is presented. Gamification provided a suitable environment for exacting accelerated, realistic, truthful self-reporting for the measures of human flourishing (HFS). Higher flourishing scores were correlated with more points, calculation of scores, and charting progress and less correlated with earning badges.	10
Hamari and Koivisto (2015)	Survey measure at a single point of time of users of an existing service. No comparison of gamification and non-gamification.	Mobile (iOS) or Website	Physical health: activity	Behaviour (system use, exercise) — positive. Cognition (intention to recommend) - positive.	non-parametric - component-based PLS (non-parametric alternative to structural equation modeling)	Rewards (Points, and achievements). Levels (level-up system). Social interaction.	200: 102 females, (20–29 years)	Study measured how social influence predicts attitudes, use and further exercise in the context of gamification of exercise. Results show social influence, positive recognition and reciprocity have a positive impact on how much people are willing to exercise as well as their attitudes and willingness to use gamification services. Gamification elements, social influence, positive recognition and reciprocity had a positive impact on participants' desire to exercise. More friends in the game was associated with a larger effect size.	10.5
Jones et al. (2014a)	Alternating treatments design, survey measures taking before and during fruit and vegetable intervention.	Game based rewards provided to heroic characters within a fictional narrative read by teachers	Physical health: nutrition	Behaviour (consumption of fruit and vegetable) - positive.	Conservative Dual Criterion using Monte Carlo simulations to compare fruit and vegetable consumption at different time-points	Rewards (equipment, currency).Narrative. Avatars.	251: 1st–5th grade students	Game based rewards were provided to heroic characters within a fictional narrative read by teachers on days when the school met fruit or vegetable consumption goals. On intervention days, fruit and vegetable consumption increased by 39% and 33% respectively. Teacher surveys indicated that students enjoyed the game and grade 1–3 teachers recommended its use in other schools.	13.5
Jones et al. (2014b)	Alternating treatments design, survey measures taking before and during intervention.	game based rewards provided to heroic characters within a fictional narrative read by teachers	Physical health: nutrition	Behaviour (consumption of fruit and vegetable) - positive.	Conservative Dual Criterion using Monte Carlo simulations to compare time-points for fruit and vegetable consumption. Wilcoxon signed-rank to analyse parent surveys.	Rewards (equipment, currency). Narrative. Avatars.	180: kindergarten – 8th grade students	Game based rewards were provided to heroic characters within a fictional narrative read by teachers on days when the school met fruit or vegetable consumption goals. On intervention days, fruit and vegetable consumption increased by 66% and 44% respectively. In post intervention surveys teachers rated the intervention as practical in the classroom and enjoyed by their students. Parent surveys revealed that children were more willing to try new fruit and vegetable at home and increased their fruit and vegetable consumption following the intervention.	13.5
Kadomura et al. (2014)	Pre-survey, 7 day user test with intervention, post survey. Post intervention interviews. Videos recorded by parents of children using device.	‘Educatableware’ — fork-type device for use with children to improve eating habits	Physical Health: nutrition	Behaviour (teaching children new eating habits) - positive.	Descriptive analysis of surveys, thematic analysis of interviews. Discussion of photos and videos.	Feedback (audio).	5: Children (1–14 years) and parents	Study describes the implementation of the device (a fork that emits a sound when the user is consuming food), and a user test with children. Generally positive results were found in response to the gamified device. Device found to have good usability and the feedback regarding the sounds used was very positive. Three of the five children showed an improvement in food consumption. Additionally, conversation during meal times was reported to improve.	12
Kuramoto et al. (2013)	12-week evaluation of intervention (survey data collected at end of each week of uses). No comparison of gamification and non-gamification. Outcomes measured with questionnaires and sensors in phone).	Mobile device (android)	Physical health: activity (standing on trains)	Behaviour (standing during commute) - positive.	not specified.	Rewards (points). Levels. Avatar.	9 undergrad students	Stand Up, Heroes! (SUH): is a gamified system to motivate commuters to keep standing on crowded public transportation in Japan. In SUH, players have their own avatars which grow larger the longer the player stands. Collecting equipment-item awards increased motivation to stand, however, once all awards were collected, motivation dropped. Watching avatars' growing-up affected participants positively throughout the study. Participants thought the game was fun.	7
Ludden et al. (2014)	Pre- and post-intervention (use of website) evaluation. Survey measures. No comparison of gamification and non-gamification.	Website	Mental health: well-being	Cognition (motivation) - positive. User experience (impression of website) — positive.	Descriptive analysis of survey results. Discussion of interview results.	Challenges. Levels. Progress (map, journey).	13: 10 females, primary school teachers (mean age 38 years)	Study evaluates ‘This Is Your Life’, a training website aimed at personal growth or flourishing. A user-centered design approach was used together with persuasive and gameful design frameworks with primary school teachers. Over half of the participants reported that the design motivated them to do the training; that they would continue using the program; and that they found it challenging and playful.	7
Maher et al. (2015)	RCT with wait-listed control condition. No comparison of gamification to non-gamification. Outcomes measured using questionnaires.	Facebook application	Physical health: activity.	Behaviour (physical activity) — mixed. Cognition (quality of life) - neutral. User experience (engagement) - positive.	Generalized Linear Mixed Models (group: intervention vs control, time: baseline, 8 weeks, and 20 weeks, and group × time interaction entered as fixed effects).	Rewards (achievements, gifts), Leaderboards. Social interaction.	110: teams of 3–8. mean age of 36 years.	Study aimed to determine the efficacy, engagement, and feasibility of a gamified online social networking physical activity intervention with pedometers delivered via Facebook app. Assessments performed at baseline, 8 weeks, and 20 weeks. At 8-week follow-up, intervention participants significantly increased total weekly moderate-vigorous physical activity (MVPA) by 135 min relative to controls (P = 0.03). However, statistical differences between groups for total weekly MVPA and walking time were lost at the 20-week follow-up. No significant changes in vigorous physical activity, nor overall quality of life or mental health quality of life at either time point. High levels of engagement with the intervention, and particularly the self-monitoring features, were observed.	12
			Mental health: quality of life
Reynolds et al. (2013)	Month long intervention with interviews at beginning and end of month. No comparison between gamification and non-gamification.	Wii balance board + Wii Fit Plus software	Physical health: activity	Cognition (motivation to exercise) - positive for beginners, negative for experienced users. User experience (attitude to system) - positive for beginners, negative for experienced users.	Qualitative analysis of interview data.	Rewards (scores, stars). Avatars.	15: 8 females, (18–59 years), beginners (not engaged in regular fitness activity for past year), non-beginners (regularly exercised before starting study)	Study reports a month-long 15-person study of first time Wii Fit users. Participants represent beginners and non-beginners with respect to past fitness experiences and current goals, and these starting points affect their experiences with the system. Beginners respond positively to gamified features. Non-beginners responded negatively (reporting that gamified features slowed down the pace of the exercise; feedback was disliked as praising was considered exaggerated).	6.5
Riva et al. (2014)	RCT (gamified vs non-gamified). Outcomes measured via survey.	Website	Physical health: activity, medication misuse, pain burden.	Cognition (patient empowerment) - positive. Cognition (pain burden) - neutral. Behaviour (medication misuse) - positive. Behaviour (physical exercise) - neutral.	Mixed design ANOVA	Rewards (points). Leaderboard.	51:26 females, (> 18 years), suffering back pain at least 3 months.	Study designed to assess the impact of interactive sections of an Internet-based self-management intervention on patient empowerment, their management of the disease, and health outcomes. Baseline, 4- and 8-week assessments of empowerment, physical exercise, medication misuse, and pain burden. Compared to the control group, the availability of gamified, interactive sections significantly increased patient empowerment and reduced medication misuse in the intervention group. Both the frequency of physical exercise and pain burden decreased, but to equal measures in both groups.	14
			Mental health: empowerment
Spillers and Asimakopoulos (2014)	Between groups quasi-experimental study (non-gamified social, light gamication and social, heavy gamification and social). Outcomes measured via questionnaires, diary studies, interviews and usage logs.	Mobile (iOS)	Physical health: activity	Behaviour (physical activity) - mixed. Cognition (motivation to exercise) - mixed. User experience (attitude to tools) - mixed.	Not specified	Rewards (badges, prizes). Challenges. Progress. Social Interaction.	15: 7 females, (Age M = 29), experienced iphone app users	Study examines the efficacy of gamification and social elements to improve motivation and lead to short-term positive behaviour change. No clear analysis of the results is undertaken. The majority of results reported are specific “user quotes” but no thematic (or similar) analysis is undertaken and no supported trends in the data are identified by the authors. Running apps designed to track a runner's activity can influence intrinsic motivation regardless of social or gamification elements. Users are more likely to engage in m-health activities if they perceive them as motivating.	7
Thorsteinsen et al. (2014)	RCT. Outcomes measured via surveys and self-reported physical activity. No comparison of gamification to non-gamification.	Website	Physical health: activity	Behaviour (physical activity) - positive. Cognition (motivation) - positive.	ANOVA	Rewards (points). Leaderboards	21: (35–73 years), healthy adults	Study designed to test the effectiveness of a gamified, interactive physical activity intervention. Healthy adults (n = 21) (age 35–73) were randomized to the intervention or the control condition. Both groups reported physical activity using daily report forms in four registration weeks during the three-month study: only the experiment condition received access to the intervention. Intervention group reported significantly more physical activity minutes than control group (in week 5 and 9 but not week 12). Participant feedback suggested that gaming components were highly motivating.	8.5
Zuckerman and Gal-Oz (2014)	RCT (3 versions of app). Outcomes measured by log file (movement tracked by phone), questionnaire data and interviews.	Mobile (android)	Physical health: activity	Behaviour (physical activity) - neutral. User Experience (usability) - neutral. User experience (attitude towards system) - mixed.	1) multivariate analysis of variance (3 version) with physical activity as outcome. 2) one-way ANOVA testing the perceived usability of the three StepByStep versions. 3) interview analysis	Rewards (points). Leaderboard.	59: 44 females, (20–27 years), undergrad students	Study evaluates the effectiveness of a gamified application designed to promote routine walking. No differences were found between the gamified and non-gamified versions. The authors speculate that the lack of difference between gamified and non-gamified versions of the tool may be because of the context (physical activity), the timeframe (several days) or the nature of the gamification employed (relatively simple). No differences were found in usability between conditions. Gamification in the form of points was considered meaningless by most users. Attitudes towards leaderboards varied between users (some very interested, some no interest).	11