Background Noncommunicable diseases (NCDs) constitute a burden on public health. These are best controlled through self-management practices, such as self-information. Fostering patients’ access to health-related information through efficient and accessible channels, such as commercial voice assistants (VAs), may support the patients’ ability to make health-related decisions and manage their chronic conditions. Objective This study aims to evaluate the reliability of the most common VAs (ie, Amazon Alexa, Apple Siri, and Google Assistant) in responding to questions about management of the main NCD. Methods We generated health-related questions based on frequently asked questions from health organization, government, medical nonprofit, and other recognized health-related websites about conditions associated with Alzheimer’s disease (AD), lung cancer (LCA), chronic obstructive pulmonary disease, diabetes mellitus (DM), cardiovascular disease, chronic kidney disease (CKD), and cerebrovascular accident (CVA). We then validated them with practicing medical specialists, selecting the 10 most frequent ones. Given the low average frequency of the AD-related questions, we excluded such questions. This resulted in a pool of 60 questions. We submitted the selected questions to VAs in a 3×3×6 fractional factorial design experiment with 3 developers (ie, Amazon, Apple, and Google), 3 modalities (ie, voice only, voice and display, display only), and 6 diseases. We assessed the rate of error-free voice responses and classified the web sources based on previous research (ie, expert, commercial, crowdsourced, or not stated). Results Google showed the highest total response rate, followed by Amazon and Apple. Moreover, although Amazon and Apple showed a comparable response rate in both voice-and-display and voice-only modalities, Google showed a slightly higher response rate in voice only. The same pattern was observed for the rate of expert sources. When considering the response and expert source rate across diseases, we observed that although Google remained comparable, with a slight advantage for LCA and CKD, both Amazon and Apple showed the highest response rate for LCA. However, both Google and Apple showed most often expert sources for CVA, while Amazon did so for DM. Conclusions Google showed the highest response rate and the highest rate of expert sources, leading to the conclusion that Google Assistant would be the most reliable tool in responding to questions about NCD management. However, the rate of expert sources differed across diseases. We urge health organizations to collaborate with Google, Amazon, and Apple to allow their VAs to consistently provide reliable answers to health-related questions on NCD management across the different diseases.

BACKGROUND Complications related to noncommunicable diseases are among the main causes of mortality. Fostering patients’ access to health-related information through efficient and accessible channels like commercial voice assistants (CVA) such as Amazon Alexa, Apple Siri, or Google Assistant, may support patients’ ability to make health-related decisions and manage their chronic conditions. OBJECTIVE This study aims to evaluate the ability of CVAs in providing expertise-based voice responses to questions related to noncommunicable disease management. METHODS We collected health-related frequently asked questions from health organizations, government, medical non-profit and popular websites about conditions associated with Alzheimer’s disease (AD), lung cancer (LC), chronic obstructive pulmonary disease (COPD), diabetes mellitus (DM), cardiovascular disease (CVD), kidney disease (KD), and cerebrovascular disease (CV). The questions were then validated with practicing medical specialists and the most frequent ones selected, resulting in a pool of 144. We submitted the selected questions to CVAs in a 3x3 fractional factorial design experiment with three developers (ie, Amazon, Apple, and Google) and three modalities (ie, voice-only, voice-and-display, display-only). The condition Google display-only was operationalized with Google Search (our gold standard of information lookup). We assessed whether the CVA provided a voice response (ie, response rate) and what type of web source was used (ie, Expert, Commercial, Crowdsourced, or Not stated). RESULTS Amazon and Google showed a slightly higher voice response rate in voice-only (76.4% and 97.2%, respectively), compared to voice-and-display (74% and 92.4%, respectively). Apple showed the opposite (16% voice-only, 16.7% voice-and-display). Source type was mostly Expert in Amazon (77.3% voice-only, 76.6% voice-and-display) and Google (70.7% voice-only, 73.7% voice-and-display). Apple mostly used Commercial (30.4% voice-only, 29.2% voice-and-display), Crowdsourced (21.7% voice-only, 33.3% voice-and-display) sources, or stated no source (39.1% voice-only, 29.2% voice-and-display). Moreover, Amazon showed the highest response rate for LC (88%), while Apple did so for COPD (20%), and Google for AD (100%). Amazon and Google always used Expert sources for AD, while Apple never did so. However, Apple used the most Expert sources for CD (50%). CONCLUSIONS None of the tested CVAs was the absolute best in responding to questions about noncommunicable disease management. CVAs seem to perform differently depending on the noncommunicable disease in question. We urge health organizations to collaborate with Google, Amazon, and Apple to allow their CVAs consistently providing reliable answers to health-related questions on noncommunicable disease management.