Table 1.

Characteristics of the included studies

Author, year	Study type	N* (I;C)	Date of intervention	Participants (setting)	Duration	Study design and comparison	Retention rates† (%) total (I:C)	Intervention
								EHR-sharing component	Other components of the intervention
Chrischilles, 2013 29	RCT	1075 (I:802; C:273)	2010–2011	General population (>65 years old) (general public—survey to voters)	6 M	2-arm study Standard care control group	100.0 (I:100.0; C:100.0)	Web-based health record Access to current and past medicines, allergies, health conditions, and health event tracking over time	Medication safety messages Display of general medication-use patient safety indicators
Earnest, 2004 21	RCT	107 (I:54; C:53)	2002	Patients with chronic heart failure (secondary care)	12 M	2-arm study Standard care control group	75.7 (I:70.4; C:81.1)	Web-based health record Access to medical record with clinical notes, laboratory reports, and test results, as well as information regarding heart failure	Secure messaging system
Fonda, 2009 14	RCT	104 (I:52; C:52)	NA	Patients with poorly controlled T2DM (primary and secondary care)	12 M	2-arm study Standard care control group	NA	Web-based health record Access to website which accepts electronic transmissions from blood pressure and glucose monitoring devices and displays these data in graphic and tabular form for the participant and care manager to review	Secure messaging system Web-enabled diabetes educational modules Links to other web-based diabetes resources
Grant, 2008 33	RCT	244 (I:126; C:118)	2005– 2007	General population (primary care)	12 M	2-arm study Active care control group (ie, access to a PHR to update and submit family history and health maintenance information)	64.0 (I:65.0; C:34.7)	Web-based health record Access to medications lists, glucose, blood pressure, LDL-cholesterol, preventive care and recent results and current treatment information	Secure messaging system (platform to reply to questions regarding adherence barriers and adverse effects of medication; check boxes and free text boxes within the PHR encouraged patients to enter therapy concerns and requests to address specific care limitations)
Green, 2008 23	RCT	778 (I1:259; I2:261; C:258)	NA	Hypertensive patients (primary and secondary care)	12 M	3-arm study Standard care control group Intervention 1(I1): home BP monitoring and secure patient Web services training only Intervention 2(I2): home BP monitoring and Web training plus pharmacist care management delivered through web communications In this work, only control and intervention one were considered	93.8 (I1:94.9; I2:90.8; C:95.7)	Web-based health record Ability to view current health conditions, laboratory test results, clinic visit summaries, and lists of allergies, immunisations, and medications	Secure messaging system Ability to refill medications and make appointments
Holbrook, 2009 15	RCT	511 (I:253; C:258)	2002– 2003	Patients with type 2 diabetes (primary care)	6 M	2-arm study Standard care control group	68.7 (I:68.4; C:69.0)	Patient and primary care provider access to diabetes tracker of 13 risk factors	Targets of risk factors Personalised recommendation messages Appointment and medication reminders
Jones, 1999 25	RCT	525 (I1:167; I2:178; C:180)	1997	Radiotherapy patients (secondary care)	3 M	3-arm study Standard care control group Intervention 1(I1): Access to general information on a computer) Intervention 2(I2): Access to personal and general information in varying order via a computer In this work only comparisons between control and I2 will be considered	83.4 (I1:76.6; I2:87.6; C:85.6)	Touch screen health record kiosk Summary of medical record, or choice between personal or general information Printout of information viewed sent to patients	Explanation about terms used were linked to in the medical records General information about cancer
Khan, 2010 16	RCT	7368 (I:3856; C:3512)	NA	Patients with type 2 diabetes (primary and secondary care)	32 M	2-arm study Standard care control group	100.0 (I:100.0; C:100.0)	Centralised laboratory results from independent laboratories (haemoglobin A1c, cholesterol, serum creatinine, and urine protein results) accessible to patients Overdue reminders and alerts to patients with elevated test results	Generation of flow sheets with laboratory results, reminders of overdue laboratory tests, and summary population reports for providers
Krist, 2012 32	RCT	4500 (I:2250: C:2250)	2008– 2009	General population (primary care)	16 M	2-arm study Standard care control group	NA	Access to relevant details in the patient’s history (prior laboratory test values and dates)	Preventive services recommendations based on EHR data Links to relevant informational material and decision aids
McCarrier, 2009 26	RCT	78 (I:42; C:36)	2005– 2006	Patients with type 1 diabetes (primary care)	12 M	2-arm study Standard care control group	83.3 (I:85.7; C:80.6)	Web-based health record Access to entire EHR with clinical encounters, physician notes, and test results	Blood glucose readings uploaded by patients Medication, nutrition, and exercise data can be registered by both patients and case managers Generations of action plans for self-efficacy and self-management support Educational information on diabetes
McMahon, 2005 17	RCT	104 (I:52; C:52)	2004	Patients with type 2 diabetes patients (both primary and secondary care)	12 M	2-arm study Standard care control group	75.9 (I:75.0; C:76.9)	Web-based care-management site with value upload for blood pressure and glucose monitoring devices Graphical and tabular view of measurements provided for patients and HCPs	Half-day self-management training on diabetes Computer training and support available to intervention participants Messaging with care manager via site Educational material
Nagykaldi, 2012 31	CRT	384 (I:NA; C:NA)	NA	General population (primary care)	12 M	2-arm study Standard care control group	68.5 (I:NA; C:NA)	Web-based patient portal with option to manage health information and download a personal health record	Personalised wellness plan, prevention and longitudinal health information available
Quinn, 2008 19	RCT	26 (I:13; C:13)	2006	Patients with type 2 diabetes patients (primary care)	3 M	2-arm study Standard care control group	NA	Blood glucose meter value sent directly to the patient’s mobile phone Real-time feedback on blood glucose levels Display of medications	Educational information
Ralston, 2009 18	RCT	83 (I:42; C:41)	2002– 2004	Patients with type 2 diabetes (secondary care)	12 M	2-arm study Standard care control group	90.3 (I:92.95; C:87.8)	Web-based EHR access Feedback on blood glucose measurements	Messaging system for patients and staff Educational information (exercise, diet and medication)
Ross, 2004 22	RCT	107 (I:54; C:53)	2001	Patients with heart failure (secondary care)	12 M	2-arm study Standard care control group	75.7 (I:81.1; C:70.3)	Web-based EHR access practice	Messaging system for patients and staff Educational information
Schnipper, 2012 30	CRT	541 (I:267; C:274)	2005– 2007	General population (primary care)	NA	2-arm study Active care control group (ie, patients received a different EHR-linked intervention)	74.3% (I:100.0% C:49.3%)	Web-based medication module linked to EHR	Ability to request appointments and referrals Communication with their physician via secure email Prescription renewals and access a health information library
Shaw, 2008 28	RCT	193 (I:97; C:96)	2004– 2006	Maternity centre (primary care)	NA	2-arm study Active care control group (ie, patients received access to the same website but with links to general pregnancy health information alone)	54.9 (I:64.9; C:44.8)	Web-based access to antenatal health record	Access to general pregnancy health information website for control and intervention groups
Tang, 2013 20	RCT	415 (I:202; C:213)	2008– 2009	Patients with type 2 diabetes patients (both primary and secondary care)	12 M	2-arm study Standard care control group	91.3 I:92.0; C:90.6	Web-based patient portal access to EHR Automatic upload of blood glucose values with visual feedback; Personalised diabetes summary; nutrition, exercise, and insulin records	Online messaging with HCPs Advice and medication management from HCPs Personalised e-educational materials
Tuil, 2007 27	RCT	244 (I:122; C:122)	2004	Patients undergoing IVF or ICSI (secondary care)	NA	2-arm study Standard care control group	73.7 (I:83.6; C:63.9)	Web-based EHR Personal and general information regarding treatment	Communication with other patients and HCPs
Wagner, 2012 24	CRT	443 (I:194; C:252)	NA	Patients with hypertension (both primary and secondary care)	12 M	2-arm study Standard care control group	71.9 (I:61.8; C:75.8)	Web-based EHR Patients could view problem and medication lists, information on allergies and immunisation	Messaging function, educational materials, medication interaction checking, health measurement tracking, and health diaries

*Total number of participants randomised for each study.

†Retention rates were calculated as the proportion of patients randomised in each study that completed follow-up.

BP, blood pressure; C, Control group; CRT, cluster randomised trial; EHR, electronic health records; HCP, healthcare professionals; I, Intervention group; ICSI, intracytoplasmic sperm injection; IVF, in vitro fertilisation; LDL, low-density lipoprotein; M, months; NA, information not available; PHR, personal health record; RCT, randomised controlled trial; T2DM, type 2 diabetes mellitus.