Design and Usability Evaluation of Mobile Voice-Added Food Reporting for Elderly People: Randomized Controlled Trial.

BACKGROUND: Advances in voice technology have raised new possibilities for apps related to daily health maintenance. However, the usability of such technologies for older users remains unclear and requires further investigation. OBJECTIVE: We designed and evaluated two innovative mobile voice-added apps for food intake reporting, namely voice-only reporting (VOR) and voice-button reporting (VBR). Each app features a unique interactive procedure for reporting food intake. With VOR, users verbally report the main contents of each dish, while VBR provides both voice and existing touch screen inputs for food intake reporting. The relative usability of the two apps was assessed through the metrics of accuracy, efficiency, and user perception. METHODS: The two mobile apps were compared in a head-to-head parallel randomized trial evaluation. A group of 57 adults aged 60-90 years (12 male and 45 female participants) was recruited from a retirement community and randomized into two experimental groups, that is, VOR (n=30) and VBR (n=27) groups. Both groups were tested using the same set of 17 food items including dishes and beverages selected and allocated to present distinct breakfast, lunch, and dinner meals. All participants used a 7-inch tablet computer for the test. The resulting data were analyzed to evaluate reporting accuracy and time efficiency, and the system usability scale (SUS) was used to measure user perception. RESULTS: For eight error types identified in the experiment, the VBR group participants were significantly (P<.001) more error prone owing to the required use of button-tapping actions. The highest error rates in the VOR group were related to incomprehensible reporting speech (28/420, 6.7%), while the highest error rates in the VBR group were related to failure to make required button taps (39/378, 10.3%). The VOR group required significantly (P<.001) less time to complete food reporting. The overall subjective reactions of the two groups based on the SUS surpassed the benchmark and were not significantly different (P=.20). CONCLUSIONS: Experimental results showed that VOR outperformed VBR, suggesting that voice-only food input reporting is preferable for elderly users. Voice-added apps offer a potential mechanism for the self-management of dietary intake by elderly users. Our study contributes an evidence-based evaluation of prototype design and selection under a user-centered design model. The results provide a useful reference for selecting optimal user interaction design. TRIAL REGISTRATION: International Standard Randomized Controlled Trial Registry ISRCTN17335889; http://www.isrctn.com/ISRCTN17335889.

Evaluating Mobile Health Apps for Customized Dietary Recording for Young Adults and Seniors: Randomized Controlled Trial.

BACKGROUND: The role of individual-tailored dietary recording in mobile phone health apps has become increasingly important in management of self-health care and population-based preventive service. The development of such mobile apps for user-centered designing is still challengeable and requires further scientific evidence. OBJECTIVE: This study aims to conduct a randomized trial to assess the accuracy and time efficiency of two prototypes for dietary recoding utilization related to the input method of food intake. METHODS: We first present an innovative combinatorial concept for dietary recording to account for dish variation. One prototype was a self-chosen tab app that featured choosing each food ingredient to synthesize an individual dish, whereas the other was an autonomous exhaustive list app that provided one selection from a comprehensive list of dish items. The concept included commercially available choices that allowed users to more accurately account for their individual food selection. The two mobile apps were compared in a head-to-head parallel randomized trial evaluation. Young adults (n=70, aged 18-29) and older adults (n=35, aged 55-73) were recruited and randomized into two groups for accuracy and response time evaluation based on 12 types of food items in use of the developed self-chosen tab and autonomous exhaustive list apps, respectively. RESULTS: For the trials based on the self-chosen tab (53 participants) and autonomous exhaustive list groups (52 participants), the two prototypes were found to be highly accurate (>98%). The self-chosen tab app was found to be more efficient, requiring significantly less time for input of 11 of 12 items (P<.05). The self-chosen tab users occasionally neglected to select food attributes, an issue which did not occur in the autonomous exhaustive list group. CONCLUSIONS: Our study contributes through the scientific evaluation of the transformation step into prototype development to demonstrate that a self-chosen tab app has potentially better opportunity in effectiveness and efficiency. The combinatorial concept offers potential for dietary recording and planning which can account for high food item variability. Our findings on prototype development of diversified dietary recordings provide design consideration and user interaction for related further app development and improvement. TRIAL REGISTRATION: ISRCTN Registry ISRCTN86142301; http://www.isrctn.com/ ISRCTN86142301 (Archived by WebCite at http://www.webcitation.org/74YLEPYnS).

Design and usability evaluation of user-centered and visual-based aids for dietary food measurement on mobile devices in a randomized controlled trial.

OBJECTIVE: We designed and developed two interactive apps interfaces for dietary food measurements on mobile devices. The user-centered designs of both the IPI (interactive photo interface) and the SBI (sketching-based interface) were evaluated. Four types of outcomes were assessed to evaluate the usability of mobile devices for dietary measurements, including accuracy, absolute weight differences, and the response time to determine the efficacy of food measurements. METHODS: The IPI presented users with images of pre-determined portion sizes of a specific food and allowed users to scan and then select the most representative image matching the food that they were measuring. The SBI required users to relate the food shape to a readily available comparator (e.g., credit card) and scribble to shade in the appropriate area. A randomized controlled trial was conducted to evaluate their usability. RESULTS: A total of 108 participants were randomly assigned into the following three groups: the IPI (n=36) and SBI (n=38) experimental groups and the traditional life-size photo (TLP) group as the control. A total of 18 types of food items with 3-4 different weights were randomly selected for assessment by each type. The independent Chi-square test and t-test were performed for the dichotomous and continuous variable analyses, respectively. The total accuracy rates were 66.98%, 44.15%, and 72.06% for the IPI, SBI, and TLP, respectively. No significant difference was observed between the IPI and TLP, regardless of the accuracy proportion or weight differences. The SBI accuracy rates were significantly lower than the IPI and TLP accuracy rates, especially for several spooned, square cube, and sliced pie food items. The time needed to complete the operation assessment by the user was significantly lower for the IPI than for the SBI. CONCLUSION: Our study corroborates that the user-centered visual-based design of the IPI on a mobile device is comparable the TLP in terms of the usability for dietary food measurements. However, improvements are needed because both the IPI and TLP accuracies associated with some food shapes were lower than 60%. The SBI is not yet a viable aid. This innovative alternative required further improvements to the user interface.