# Privacy and Security in Digital Health Contact-Tracing: A Narrative Review
## 3 Results
### Trust
#### 3.3.3 Trust in App and Technology  
Many users have expressed concerns about the contact-tracing app's ability to ensure privacy and security. They felt that the app invades the privacy of their smartphones and that there is no guarantee of privacy when using it [63]. There was a positive relationship between distrust in digital contact-tracing and resistance to using the contact-tracing app. It meant that people who had high distrust in the contact-tracing app were likely to resist using it [57]. Perceived trust in the contact-tracing app was one of the positive determinantsof intention to use [21; 39]. In China, it was reported that people carefully assessed risks, resulting in increased mistrust and doubt about epidemic prevention technologies [83].  
In Canada, the perceived trustworthiness of the app was one of the particularly significant factors in its adoption [81]. The functionality and effectiveness of the app mainly determined participants' trust. If participants perceived these aspects to be deficient, then trust was low. Conversely, trust level was higher when the contact-tracing app was considered effective [77]. In the USA, some participants expressed concerns about information being intentionally or accidentally leaked. participant believed that a mobile application database had a higher risk of being hacked than information in a public health department's database. Participants perceived that technology, especially mobile apps, could easily lead to information leakage [115].  
In contrast, in Germany, the examination of trust in the contact-tracing app and its developers did not show a significant direct relationship with app adoption [44]. In Vietnam, trust positively influenced the behavioural intention to adopt a certain contact-tracing technology [32]. In Qatar, participants considered contact-tracing apps trustworthy, and there was a significant positive correlation between trust and user satisfaction, which can be defined as the difference between expectations and perceptions [123]. Furthermore, trust had a statistically significant and negative effect on privacy risk, suggesting that higher levels of trust were associated with lower perceived privacy risks [32]. Further, distrust toward human tracers reduced participants' willingness to disclose personal information. Some participants mentioned their reluctance to talk to strangers about their health or lifestyle. Specifically, there was a fear that revealing demographics could potentially lead to racial discrimination. As a result, some participants expressed a preference for contact-tracing technology as a way to mitigate concerns related to racial discrimination [115].  
In the USA, many people are hesitant to use contact-tracing technologies because they lack confidence in digital technology [42].This is mainly due to the fact that even when the information is presented in the user's native language on their smartphone, it can still be unfamiliar to those with limited digital skills [42].  
In an Italian study, it was found that people in a particular group tended to download more apps on their smartphones, irrespective of the permissions required. This observation was consistent with the higher number of downloads than anticipated. It seemed that individuals in this cluster had more trust in using technology and smartphone apps [124].  
A study conducted on Chinese tourists has reported that tourists' trust in health QR codes is affected by knowledge, perceived efficacy, privacy risk, and security. People's trust in digital health applications can increase acceptance of tracing technology [125].