Median System Usability Score scores by EHR system
| System supplier | Number of responses | Number of organisations | Median SUS (95% CI) | IQR |
| Allscripts (Oasis/Sunrise) | 77 | 11 | 48 (38 to 53) | 35–65 |
| Atos (Sema-Helix) | 27 | 2 | 35 (30 to 50) | 25–55 |
| Cerner (Millennium/FirstNet) | 305 | 23 | 55 (53 to 58) | 40–70 |
| DXC, was CSC (Lorenzo/EDIS/i.PM) | 197 | 20 | 40 (38 to 45) | 25–60 |
| EMIS (Symphony) | 359 | 39 | 53 (48 to 53) | 38–63 |
| Epic | 32 | 3 | 63 (50 to 80) | 46–83 |
| Ideagen (Patient First) | 67 | 9 | 60 (55 to 65) | 48–70 |
| IMS Maxims | 31 | 7 | 53 (39 to 63) | 35–65 |
| Intersystems (TrakCare) | 78 | 16 | 50 (38 to 55) | 28–63 |
| Meditech | 49 | 7 | 60 (53 to 75) | 45–83 |
| NerveCentre | 46 | 3 | 65 (57 to 75) | 43–80 |
| Servelec (Oceano) | 31 | 4 | 53 (48 to 59) | 38–65 |
| Silverlink (iCS/PCS) | 29 | 7 | 38 (32 to 46) | 30–50 |
| System C (Medway/Sigma) | 154 | 18 | 55 (50 to 58) | 43–70 |
| Welsh Clinical Portal/PAS | 21 | 7 | 45 (31 to 59) | 30–63 |
| Overall | 1503 | 176 | 53 (50 to 53) | 35–68 |
EHR, electronic health record; SUS, System Usability Score.