The health record function provides patients options to view clinical documents that can be retrieved from health providers’ EHR [22,23,34]. This information can include problem lists [22,24-29,45,56,67-71], allergies [22,25-28,30-33,35-39, 56,67-70], immunization [22,26-28,30,32-35, 40-42,56,68-71], laboratory and test results [22,24,26-30,33,36,37, 40,42-61,67-71], diagnostic information [32,37,44,45,62], discharge information [31,34,63], and clinical notes [24,30,33,42,50,61,64,67,69]. Figure 3 shows an example of test results in PittPHR [33].

This function can also include information about medical history [22,24,30,33,35,37,39,45,51,57,64,65,67,68], family history [28,30,32,33,35,37,66], genetic history [45], surgical history [26,28,33,35,45,66,68], social history [32,33,35,37,45,68]. Some studies suggested that this function also supports patients’ ability to print the record [24,36] and add comments or notes in health records [28,61].

This function enables the patient to manage information about demographics or personal information [25,26,31,44,45,68,72] such as name [25,39,44,72,73], gender [25,26,44,72], birthdate [25,26,44,72,73], blood type [39,44], contact information [25,31,68,72], and parents’ names [25,45]. Patients can also change their information, such as change password, address, and email address [22]. Patients can enter this information [22,31,68,72] or retrieve it from a central patient registry, such as in Lifelong PHR [34].

Patients can also view health professionals’ information, such as name of health worker [34,39,55,74], role [74,75], educational background [75], contact information [42,45], specialty [76], location [76], and pictures [46,55,59,74,77,78]. Patients can also view hospital information, such as location, contact info, address, navigation [70]. Patients can also view and pay bill [42,55,77] and get insurance-related information [22,30,34,45,66]. This data can be retrieved from the regional health care information system [34]. Figure 4 shows an example of the health care team information in the PHR app [74].

Health care providers publish prescriptions to the patient’s PHR, while pharmacists dispense the prescribed medication [34]. This function provides information about the list of medications that patients are currently taking [25,28,29,35,38,45,46, 52,56,59,60,68,69], medication name and dosage [32,35,40,60,74,77,79,80], and list of past medications [28,29,36,42,45,46,60,69,70,73,81]. PHRs should also add information about the purpose or class of medications to give patients an understanding of the medication type [74] and allow pharmacists to explore the data according to their common questions [80].

This function also allows patients to view list of prescribed medications [26,30,39,54,79,82,83], prescribing physician [79], refill prescription [24,27,29-31,33,34,36,39,48,53,55, 57,60,61,84], order medications [29,39,71], deliver purchased medication [79], as well as track the delivery of medication [36,39,42]. Some PHRs also provide medication schedulers and reminders of when to take medicines [28,70,83,85], drug or medicine reconciliation [42,51,63,83], and warning alerts of potential adverse interactions based on the medication and allergy list [38,68,73]. Figure 5 shows an example of medication management in medication management in My Chart in My Hand [85].

The patient can send messages to the health care provider to inform them of health condition [23], share doubts and worries [86], receive medical advice [56,86], or send nonurgent messages [40,46,71]. The communication can be in the form of messaging [23,27,29-32,36,38,40,42,43,46,48,49,51-53,55-57, 59,61,67,69,71,74,75,82-84,86-92] or text where patients can write questions (Figure 6) [74,80]. Some PHRs also enable patients to contact others in a similar situation [28,29,83,88], support groups [62,87], family [75,89], or customer support and billing departments [22]. Some studies also suggested this function have the ability to maintain a record of past conversations [36] and provide email or text notification when a health care provider leaves a message on the PHR [24,93,94]. Moreover, some studies suggested tracking the status of a question [80], message multiple providers at the same time [24], and import selected emails and interactions on the social network to PHRs [86].

Some PHRs may allow a patient to request or schedule appointments (Figure 7) [22,23,25-28,30,33,34,40, 42,48-50,52,55,57,60,61,67,71,85,87,92], while others only allow patients to view their past and upcoming appointments [29,31,36,51,53,56,59,63,64,73,77]. The types of appointments can include patient-doctor visit consultation services and other health services such as specialist encounters, sample takings, hospital admissions, result withdrawal [86], therapies, and online consultation [23]. Moreover, some studies suggested that PHRs include reminders or notifications for upcoming appointments [33,42,47,48,60,61,81,94]. This reminder can be in the form of email notifications about the date and time of the appointment [42,81]. PHRs can also add a calendar to keep track of future appointments [34,78].

The education function can include resources from trusted websites [45,90], health information libraries [22,30], video resources [46,59,95], or government supported information [95]. The information can consist of lifestyle management [45,57,71], first-aid information [40,70], discharge instructions [31], surgical procedure [77], physical activities guidance [96], or health-specific education such as pregnancy [97,98], mental health [45,61], or chronic diseases–related education [90,95]. Figure 8 shows an example of the education page in the Maternity Information Access Point [97]. Health providers are responsible for providing clinical topics and resources for credible information [55,76,99]. Moreover, PHRs should also have the ability to search for information using an intelligent search engine [99].

Patients can manage their own health related to nutrition and diet information such as weight [30,33,39,58,66,67,72,85,86,90,98,100-102], height [39,58,66], physical activity or exercise [30,33,58,66,70,96,98,100,101], and food and meals [33,66,98]. Patients can also manage their vital sign data such as temperature [26,44], blood pressure [30,33,44,58,66,67,70,72,85,90,98,101,103], blood glucose [30,58,66,70,72,85,86,98,103], and heart rate [90]. Patients can also monitor other self-health data such as sleep [33,66,95,100,101], period [33,100], moods [98,100,101], and stress [66,70,100].

These clinical measures enable calculation such as BMI [39,66,70,85,100], body fat percentage [70], waist-to-height ratio [70], calorie [70], cholesterol level [66,86], and glycemia [86]. This information can also calculate disease risks such as cardiovascular disease risk and metabolic syndrome risk [85]. The data in this function can be retrieved from home monitoring devices [23,39,58,85,96,104,105] such as Bluetooth-enabled health monitors [104], accelerometers [105], blood pressure monitors [58], blood glucose meters [58,81,85,93], and pedometer [72] and fitness tracker apps [39].

The monitoring of health data can be shown as a dashboard that visualizes data in graphs, charts, or diagrams [30,33,70,72,81,86,101,102,105]. Key performance indicators can be different for each patient, depending on their conditions. For example, in the MyHealthKeeper app, the clinician provided individual diet and physical activity targets for each patient during an outpatient visit (Figure 9) [101]. This function can be integrated into a clinician’s EHR, and clinicians could review these data and provide feedback about the health-related lifestyle management of their patients [101].

An important issue raised in several studies is PHR compatibility with other systems [51,88,90,100,106]. Health service providers such as clinicians should input data from other systems into the PHR or vice versa, which was considered too time-consuming and unfeasible for daily practice [100]. This problem can also be caused by health organizations adapting their formats to use health records and not allowing health information sharing in their PHR to other applications or organizations [63,107]. As a result, a patient may have health records scattered in several applications [107]. To provide more benefits and ensure its successful implementation, PHRs should realize interoperability among various data and systems [106,108]. PHRs should have the ability to share information with others [88], such as health professionals [37,61,89].

In the tethered or integrated PHR, patients may connect their PHR to the health care provider system [25,62,72,76,86,102,104]. With this integration, health information is automatically transferred to the PHR [33,39,62,109,110]. This can reduce data entry load [33,96], improve data accuracy [62,96], prevent medical errors [38], reduce the health information recall [35], and contribute to users’ better perceptions about the system’s usefulness [111]. It is also suggested that PHRs be integrated into various health providers and not limited to one health provider [53,102]. Patients may also have the ability to share information with trusted institutions and insurance bodies to speed up reimbursement procedures [86] and access other family members’ records [22,102].

It is necessary to create legislation to realize PHR interoperability [106]. Health providers need to provide standard definitions for data exchange and cooperate with other providers [63]. There are international standards or frameworks for interoperability, such as OpenEHR, Health Level 7 (HL7) Fast Healthcare Interoperability Resources (FHIR), and Integrating the Healthcare Enterprise and Continua Health Alliance specifications [29,68,72,107,112]. OpenEHR describes the management and exchange of data in EHRs for developing PHRs using specific language [68]. OpenEHR integrated with other standards in particular health data types, such as laboratory results [107]. Similarly, HL7 FHIR enables the management of a single data entity, group of entities, or a record using well-known standard languages [68]. FHIR application program interface allows any arbitrary system connected with another medical system already equipped with the FHIR application program interface [72]. FHIR allows the patient portal to be interconnected but independent [29]. Moreover, Integrating the Healthcare Enterprise specifies architectural approaches using international standards for the health data exchange and can fit the mobile platform’s resources. At the same time, Continua enables communication from personal health devices to EHRs and PHRs [112].

PHRs contain personal and sensitive data [47,77,108,112-114]. Some people have concerns about storing these data online [54,103,108,113,115] and consent to use the system [116]. They may have concerns about identity theft and unauthorized access in PHRs [54,55,57,61,69]. Confidentiality and privacy of information in PHRs should be ensured through secured access to PHRs [110].

To ensure the security of information, PHRs should use a single sign-on mechanism [70], user authentication [26,33,64,72,73,112,117], authorization [42,112], identity verification [34,63], encryption [25,33,112,118] or pseudonymization [114], backup mechanism [25,33,72], and firewalls [72]. PHRs can also implement an access log so that users can see who viewed and downloaded information [76]. The use of complicated or complex passwords can improve the security of s [47,119]. However, some studies show that users have difficulty remembering their passwords [47,74,77,92,94,97,103,120]. Thus, PHRs should also add other methods such as fingerprint authentication [97], biometric identification [33,94], citizen digital certificate [121], and allow users to change their passwords [62,72].

To address privacy concerns related to data sharing, PHRs should have the ability for patients to choose what information to share and who can see that information [34,42,45,60,61,65,76,83,121,122] and provide a privacy policy in the system [32]. The consent model should also be considered in implementing PHRs [116]. Moreover, PHR systems need to follow specific legal requirements related to security and privacy defined on regional, national, or international levels [112]. For example, the Health Insurance Portability and Accountability Act ensures secure data exchange with entire clinics [76].

Some usability problems identified in selected studies include font or text size that are difficult to use [71,94], confusing format [81], unclear visualization of data [90], problem with navigation [51,59], and complicated data entry [85,118]. Complicated data entry may cause users to not enter data correctly into their PHR [118]. The reduction and simplification of PHR system data entry should be considered in PHR design [35,93,118]. Users prefer easy to use, simple, and user-friendly interface [24,41,45,54,61,62,65,92,94,110,118,120-124]. Users are also interested in attractive and interactive systems [25,33,108,110,120,124] such as the use of contrasting colors for scroll bars and menu items [59]. Moreover, it is also important to maintain consistency and standardization of interfaces [35,74,117,118]. A mobile app version of the PHR was also suggested because it was perceived as more user-friendly and easy to use [25,34,61,65,81,93,100].

A PHR may add a section to guide patients about the features in the PHR [46,54,59,61,65,83,90,96,118] and quick access to the essential functionalities [37,48,108]. The use of user-interface elements like buttons and a dropdown menu can enhance the user-friendliness and simplicity of the PHR interface [25,100]. However, icons should be avoided when designing for older adults since they may not recognize them [96]. PHRs should be easy to understand and navigate for all user groups [110], including those with basic computer knowledge and those who are not computer literate [94,118]. PHR usability should be determined using health literacy assessments and there should be different PHR versions for specific groups of users [36].

Developers should involve users in designing, updating, or improving PHR systems [48,71,119]. Using a user-centered design approach can facilitate users’ involvement in PHR design [76,87]. The user-centered design process increased the development process’s complexity, but the product quality was higher, especially satisfaction and user acceptance [105]. However, user-centered design may not apply to all PHR types, especially PHRs targeting the general population, which necessitates identifying specific user groups and specific use contexts [125]. Adopting a usability design framework that includes usability and user testing may help address PHR usability issues [126]. Standardization used for PHR design is International Standards Organization (ISO 9241-210), which focuses on the requirements and user needs [105], and ISO 9241-11 for software systems components that define usability [96].

Health care providers may doubt patient-entered data in a PHR [30,113]. Not all patients have enough knowledge to generate health data in a PHR [107,112]. Data uploaded by the patient may be inconsistent [91], incomplete [81,90,110], inaccurate [30,81,90,110,115], or not up to date [90]. PHRs require patient commitment to keep the system up-to-date and relevant over time [111]. This issue needs particular attention, especially when PHR data are transferred to EHRs and used in professional medical decision-making and treatment processes [112].

To ensure data quality of patient-generated data in PHRs, health care professionals need to take time to supervise the quality of information generated by patients in PHRs [110,112]. PHRs should differentiate patient-generated data from the health care provider’s data [68]. Moreover, PHR design needs to define what information is required because an incomplete record is preferable to an inaccurate one from a provider’s perspective [35]. Standardization of patient-entered information is essential to ensure data quality [33]. Input control should be comfortable and descriptive words should appear to help patients enter PHR data [108].

In tethered PHRs, which are tied to EHRs in health organizations, health information on the PHRs are created automatically from the original patient clinical reports to make this information more reliable [34]. However, this can be a problem if the EHR’s information is incomplete [30,64] or if the information is not generated automatically. This can also be caused by health care providers not updating the PHR information consistently [24,31].

Some users may have more health issues than others, such as older patients having more health issues, appointments, and information to manage [22]. People want the PHR to be tailored to their needs and capable of changing based on their health and well-being needs [59,78,88,102,123]. This person-specific health and well-being information can make the PHR system more appealing [118]. The PHR system needs to be adaptable and extensible to ensure successful operation [112]. It is also suggested that PHRs support customizability based on computer literacy [87].

PHR systems should provide medical information that can be dynamically adapted to patient preferences for simpler or more complex information [99] [117]. For example, in PittPHR, users can customize the trackers according to their own needs by hiding or unhiding available trackers in a given list and add or delete links in the resources module according to their own needs [33]. PHRs could also provide tailored health education materials based on patient health problems [52,57,95,117]. Despite the need for personalization, designers or developers need to define the extent to which PHRs can be personalized but still maintain standardization, uniformity, and simplicity [125].