Health Apps in Detail: How to Evaluate Quality and Safety

Health apps are becoming increasingly popular, offering users convenient support for health issues such as obesity, diabetes, or mental illnesses. A survey by Civey shows that almost one-third of Germans (31.6 percent) use such apps. Dr. Petra Müllerová from Lund University in Sweden estimates, based on a 2021 IQVIA study, that there are about 350,000 health apps worldwide. Notably, only 110 of these apps account for half of all downloads. The COVID-19 pandemic further accelerated this trend.

Health apps include medical applications such as Germany’s digital health apps (DiGA), as well as numerous wellness, sports, and lifestyle apps. About 22 percent of health apps focus on mental health, with significant variations in their quality and safety. While many apps for meditation and yoga are unproblematic, others that aim to diagnose or treat illnesses can be risky. Most health apps in the App Store have not been scientifically tested and do not require CE marking (CE for "Conformité Européenne"). EU regulations set basic safety and health requirements for products. CE marking indicates that the product meets the standards set by the European Union. Among over 8,700 German-language apps in the health and fitness, as well as medical categories, only 41 mention their quality certification in the App Store. According to certification providers and CE testing bodies, at least 100 apps could have received a seal or CE marking. Of these 41 apps, 34 mentioned their CE marking in the App Store, while five apps referred to one of 13 different non-governmental quality seals, such as the AppCheck from the Center for Telematics and Telemedicine (ZTG), the HealthOn seal, the DiaDigital seal, EuroPriSe, HONcode, Stiftung Warentest tests, Trusted Apps, the TÜV-Süd software test mark, or the eprivacyseal. This discrepancy stems from the fact that a seal is not necessarily required for listing an app in the App Store, nor do they need to be developed by healthcare experts.

Apps that use artificial intelligence (AI) and chatbots are particularly complex, as there are both certified and unregulated applications. With the increasing demand for health apps, the need for precise differentiation is growing, as apps vary greatly in their areas of application and methods. They can be broadly categorized into health promotion, prevention, and medical apps. In practice, health promotion and prevention often overlap, making a clear distinction difficult.

Despite the wide range of health app offerings, it is advisable to be aware of certain risks, as they can also cause harm. Risks include providing misleading information, encouraging actions that could harm health, giving incorrect diagnoses, transmitting faulty measurements to users, or selling users’ health data to external companies. In some cases, these issues may have minimal impact, but they can sometimes lead to serious consequences. Therefore, it is crucial to carefully assess the quality of a health app. There are several indicators that can help evaluate the quality of an app. For example, positive reviews and high download numbers do not necessarily indicate quality. Some providers even buy positive reviews to rank higher in the App Store. On the other hand, an app with fewer downloads and reviews may still be of high quality. Several aspects of the app description should also be considered. A clear definition of the app's function is important. The description should indicate any limitations, such as clarifying that the app cannot replace a doctor’s visit. It should also state which target audience the app is suitable for and which it is not. If the app poses potential risks to certain groups (e.g., people with epilepsy or back problems), this should be transparently communicated in the App Store description. Additionally, it is important to know whether the app is suitable for children and adolescents. Furthermore, any requirements for using the app should be clearly stated. If special settings or additional devices are necessary, this should also be mentioned in the description. Some apps, for example, require access to the user’s location or an active internet connection, while others only work in conjunction with a smartwatch. As mentioned in the post "Health Information on the Web: How to Handle It and What Influences the Use of Health Information?", it is also important for the app to have an accessible legal notice or imprint.

Regarding the financing of health apps, there are both free and paid options. If an app is offered for free, it is usually funded by other sources. It is important that the app description in the store clearly states how the app is financed to avoid hidden costs. Most financing models involve sponsorship, paid advertising, in-app purchases, trial phases, paid use, or the sale of user data.

Many health apps collect personal data such as age, gender, height, weight, and activity data like steps or sleep patterns. This information is particularly sensitive and should not be shared without clear consent. According to the General Data Protection Regulation (GDPR), it is generally prohibited to process such data unless users have explicitly consented. Before using a health app, providers must clarify certain points in a privacy policy, such as the purpose of data collection, where and how the data is stored, or what security measures are in place against data loss or theft. Some apps function only to a limited extent until users agree to the privacy terms. It is advisable to review which terms have been agreed upon and whether consent can be withdrawn at any time. Data deletion is often only partial and not complete. More information on data protection and GDPR can be found on the website of the Federal Commissioner for Data Protection and Freedom of Information at bfdi.bund.de.

Regarding the content of health apps, the health information should be well-researched by professionals: current, accurate, complete, and verifiable according to Good Practice of Health Information (GPGI) standards. This information should be updated regularly, as medical knowledge evolves constantly. Ideally, an app should be updated at least every six months. Health information should be neutrally formulated and not favor specific products or methods. Instead, it should objectively present multiple options and outline their advantages and disadvantages. If the app provides ratings or recommendations, these should be clearly distinguishable from other information. All information should be backed by credible sources, and the provider should state the sources and their recency to ensure the scientific validity of the information. If the app includes exercises or instructions, they should be clearly understandable. Users should be able to adjust the difficulty level, track progress, and have a clear interpretation of the measured values. The app should only collect data necessary for its function. Access permissions for smartphone features should only be requested if absolutely necessary, such as GPS location sharing or calendar access. The app should function technically flawlessly to ensure reliable use.

Checklists can be used to verify the trustworthiness and assess the risks associated with using health apps. The ÄZQ (Medical Center for Quality in Medicine) offers checklists for reducing risks. There are also various app checkers such as KV App Radar, AppCheck, or healthon.de that help assess the value and risks of an app or how well it aligns with the quality criteria for health information.

In summary, many risks exist when using health apps. This article outlines the most important indicators of potential risks. To further evaluate apps, checklists and app checkers can be used. Like websites, health apps do not replace a doctor’s visit, so it is always advisable to seek personal medical help. This article does not assume liability for actions taken when using health apps and is intended solely for educational purposes.

Sources: 

Ärzteblatt, D. Ä. G., Redaktion Deutsches. (2018, Mai 3). Die wenigstens Medizin-Apps werben mit Gütesiegeln oder einer CE-Kennzeichnung. Deutsches Ärzteblatt. Source

BfGA. (2024). CE-Kennzeichnung—Definition. BfGA Beratungsgesellschaft für Arbeits- und Gesundheitsschutz mbH. Source

gesund-im-netz.net. (2024). Gesundheits-Apps. Gesund-im-Netz. Source

IHK Ratgeber. (o. J.). CE-Kennzeichnung | IHK München. Abgerufen 7. Oktober 2024, Source

klick2health.net. (2024). Gesundheits-Apps. Klick2Health. Source

Scherenberg, V. (2022). Gesundheits-Apps. In: Bundeszentrale für gesundheitliche Aufklärung (BZgA) (Hrsg.). Leitbegriffe der Gesundheitsförderung und Prävention. Glossar zu Konzepten, Strategien und Methoden. Source