Assessment of the quality of mobile apps for food allergy

IgE-mediated food allergies are common, affecting 1 in 10 adults and 1 in 12 children, and can be life-threatening and detrimental to quality of life.¹ Digital technology has great potential for helping patients prevent, identify, and manage food allergy reactions. The Food and Drug Administration defines a mobile application (app) as a software app that can be executed on or is tailored to a mobile platform.² Health is one of the most common subjects searched on mobile phones,³ and currently, more than 300,000 health apps are available.⁴ In 2021, 85% of Americans owned smartphones and had access to apps.⁵

The goal of this study was to examine the content and quality of food allergy apps that are available in the Apple App Store. We used the Mobile App Rating Scale (MARS), an objective and validated tool for classifying and assessing the quality of apps.⁶ Previously, a review of food allergy apps was performed in 2015 prior to Apple removing 1.4 million apps that had not been updated.^7,8 A second review conducted in 2020 was limited to 14 apps with high user star ratings; however, apps with low ratings could be high quality.⁹ Understanding available food allergy apps will not only help clinicians increase awareness of the types of apps patients may be using but also advise patients on which apps are potentially beneficial.

We performed a search in the Apple App Store in August 2021, using the keywords “food allergy” and “food allergens,” and found 162 apps. We excluded apps that were not in English and unrelated to IgE-mediated food allergies (eg, apps for food intolerance or weight loss). We categorized the remaining 48 apps on the basis of their function (see Table E1 in this article’s Online Repository at www.jaci-inpractice.org).

Two authors, who completed the web-based training for MARS, independently classified each of the apps. The MARS criteria measure 4 objective quality scales on engagement, functionality, aesthetics, and information quality; 1 subjective quality scale; and 1 app-specific scale assessing the perceived impact of the app on the user’s knowledge, attitudes, and intentions regarding the target health behavior. Each category was scored on a 5-point rating scale anchored from 1 to 5 (1: inadequate, 3: acceptable, to 5: excellent).

The 48 apps were categorized into the following categories: allergen identification (n = 19), support for gluten allergies (n = 15), recipes for individuals with food allergies (n = 14), health education (n = 12), allergy support or communication (eg, connecting with individuals with food allergies and calling emergency medical services) (n = 11), allergy-friendly restaurants (n = 9), help with travel (eg, translating food allergies or ingredients and locating allergy-friendly hotels) (n = 10), storing allergy profiles (n = 7), and diary to track allergy symptoms (n = 5). Each app could be assigned to more than 1 category. The category with the greatest number of apps was allergen identification, with 19 apps. Many of these apps make use of smartphone cameras to allow users to scan barcodes of products to bring up ingredient lists. Of all the apps, ShopWell — Better Food Choices had the highest app quality rating of 4.29. With this app, users can scan a barcode to find out whether the product has specific allergens and discover new allergen-free products. The app with the second highest app quality score, Eat! Gluten-Free, helps users find recipes, products, and services that are gluten-free.

Nine apps help users find restaurants and companies that are allergy friendly. For example, Spokin, which has an app quality score of 3.93, allows users to select their specific allergens and find allergy-friendly restaurants and hotels. Some of the apps provide information on restaurants in specific geographic areas, whereas others provide information on restaurants nationally or globally. Additional apps help users create a profile to share their child’s allergy profile, inform others of food allergies in different languages, join a support group, or provide other support (Table E1).

Our ratings showed high internal consistence (Cronbach α = 0.91) and an interrater reliability interclass correlation coefficient of 0.81. Across all apps, the MARS app quality score is acceptable (mean, 3.31 ± 0.43), but the overall subjective quality (mean, 2.14 ± 0.62) and app-specific rating (mean, 2.77 ± 0.71) were poor (Table I). The mean overall subjective quality scores were lower than the other MARS score categories, possibly because of the subjective question: “Would you pay for this app?” It is possible that an app can have high MARS ratings overall but not be worth paying for. The highest mean app quality scores were for the categories of recipes (3.49 ± 0.50), allergy profiles (3.39 ± 0.53), allergen identification (3.34 ± 0.49), and health education (3.34 ± 0.56). Interestingly, the highest rated apps based on the MARS were not more commonly downloaded. There was poor correlation between the app quality and user star ratings, with an interclass correlation coefficient of 0.17 (Cronbach α = 0.43).

TABLE I.

Evaluation of apps in each category using the MARS

Category	No. of apps	App quality*	Engagement	Functionality	Aesthetics	Information	App subjective	App- specific
All apps	48	3.31 ± 0.44	3.02 ± 0.53	3.69 ± 0.42	3.24 ± 0.59	3.30 ± 0.47	2.14 ± 0.62	2.77 ± 0.71
Allergen identification	19	3.34 ± 0.49	3.12 ± 0.45	3.67 ± 0.52	3.33 ± 0.66	3.26 ± 0.52	2.25 ± 0.67	2.70 ± 0.63
Allergy profiles	7	3.39 ± 0.32	3.09 ± 0.45	3.80 ± 0.39	3.26 ± 0.50	3.42 ± 0.20	2.09 ± 0.51	3.15 ± 0.75
Allergy support/communication	11	3.28 ± 0.35	2.95 ± 0.56	3.69 ± 0.33	3.14 ± 0.46	3.33 ± 0.34	2.00 ± 0.48	3.11 ± 0.48
Allergy tracking	5	3.29 ± 0.29	3.08 ± 0.47	3.70 ± 0.26	3.17 ± 0.39	3.21 ± 0.41	2.03 ± 0.56	2.30 ± 0.86
Gluten	15	3.23 ± 0.55	2.95 ± 0.51	3.59 ± 0.56	3.20 ± 0.66	3.17 ± 0.60	2.04 ± 0.72	2.56 ± 0.75
Health education	12	3.34 ± 0.45	3.00 ± 0.58	3.73 ± 0.41	3.18 ± 0.54	3.45 ± 0.51	2.19 ± 0.63	3.35 ± 0.80
Recipes	14	3.49 ± 0.46	3.19 ± 0.60	3.76 ± 0.39	3.54 ± 0.65	3.46 ± 0.42	2.36 ± 0.62	2.84 ± 0.72
Restaurant information	9	3.32 ± 0.47	3.18 ± 0.50	3.54 ± 0.49	3.28 ± 0.59	3.27 ± 0.45	2.07 ± 0.57	2.84 ± 0.68
Travel	10	3.17 ± 0.37	2.83 ± 0.60	3.64 ± 0.38	3.03 ± 0.48	3.19 ± 0.32	1.98 ± 0.48	3.01 ± 0.62

Values are mean ± SD.

^*App quality is the mean score of engagement, functionality, aesthetics, and information.

In 2015, the Apple Store had 77 food allergy apps available, whereas only 48 apps are available today. Of the 77 apps, only 6 are still available, suggesting high turnover.⁷ The previous review noted that no apps had the ability to scan ingredient lists for potential allergens; currently, multiple apps have this capability.⁷ Importantly, no previous or current app aids in distinguishing a food allergy from food intolerance, because current apps are for individuals with diagnosed food allergy; distinguishing the 2 could be an area for future development with careful guidelines.

Strengths of this study include the categorization and objective evaluation of all currently available apps in the Apple App Store for food allergy. Limitations of this study include that we did not review any paid apps, apps not in English, apps outside of the Apple App Store, and we did not explicitly include limitations of each app. Although many of these apps are compatible with Android, we did not evaluate apps in Google Play.

In summary, more than 48 apps for food allergy are currently available for iPhone users, and food allergy apps have been downloaded more than 8 million times, suggesting reasonable usage given there are 26 million adults with food allergies in the United States.¹ Overall, clinicians should be aware that available food allergy apps for recipes, allergy profiles, allergen identification, and allergy education have acceptable ratings and could complement patient care.

Clinical Implications.

Numerous mobile health applications are available to patients with food allergies, which include features such as recipes, education, sharing of food allergy profiles, and identification and translation of ingredients. The applications were overall acceptable when using a validated rating criteria.