| Test ordering | 125 (12.9) |
| Needed test not ordered | 29 (3.0) |
| Wrong test ordered | 11 (1.1) |
| Unnecessary test ordered | 16 (1.7) |
| Ordered test at wrong time | 2 (0.2) |
| Contraindicated test ordered | 1 (0.1) |
| Wrong test/patient name recorded in log | 7 (0.7) |
| Test not entered into log | 3 (0.3) |
| Lab order misinterpreted | 2 (0.2) |
| Incomplete or illegible lab order slip | 40 (4.1) |
| Errors in ordering investigations (not otherwise specified) | 14 (1.4) |
| Test implementation | 173 (17.9) |
| Requested test not done (including specimen not drawn, image not booked) | 65 (6.7) |
| Specimen improperly collected or stored/old or inadequate specimen | 22 (2.3) |
| Specimen lost | 23 (2.4) |
| Specimen/patient sent to wrong facility | 5 (0.5) |
| Delay in obtaining specimen | 3 (0.3) |
| Wrong specimen obtained | 1 (0.1) |
| Stat or urgent test not processed or scheduled urgently | 7 (0.7) |
| Wrong test performed or scheduled | 21 (2.2) |
| Right test performed wrongly | 3 (0.3) |
| Failure to instruct patient how to prepare for investigation | 1 (0.1) |
| Test done, but results lost | 5 (0.5) |
| Failure to alter medications for diagnostic procedure | 4 (0.4) |
| Errors in implementing investigations (not otherwise specified) | 13 (1.3) |
| Reporting results to the clinician | 238 (24.6) |
| Failure to report test results in a timely manner | 58 (6.0) |
| Failure to report correct results (wrong values on report) | 11 (1.1) |
| Results never received by office | 52 (5.4) |
| Incorrect interpretation of results by facility or laboratory | 3 (0.3) |
| Previous results, images and specimens could not be found for comparison | 1 (0.1) |
| Incorrect/incomplete information on report | 49 (5.1) |
| Failure to report test results to provider requesting test | 46 (4.8) |
| Errors in reporting investigations to office (not otherwise specified) | 18 (1.9) |
| Clinician responding to the results | 64 (6.6) |
| Responded incorrectly to test results | 4 (0.4) |
| Failure to notice or respond to abnormal test results | 16 (1.7) |
| Failure to notice or respond to abnormal test results in a timely manner | 27 (2.8) |
| Inappropriately responded to incomplete test results | 3 (0.3) |
| Failure to notice or respond to normal test results | 1 (0.1) |
| Failure to notice or respond to normal test results in a timely manner | 5 (0.5) |
| Responding to investigation results (not otherwise specified) | 8 (0.8) |
| Notifying the patient of results | 66 (6.8) |
| Failure to notify patient of test result | 17 (1.8) |
| Failure to notify patient of test result in a timely fashion | 37 (3.8) |
| Failure to notify patient of test result in a sensitive manner | 1 (0.1) |
| Test results given to wrong patient | 6 (0.6) |
| Informed patient about same result more than once | 2 (0.2) |
| Incorrect test results given to patient | 2 (0.2) |
| Notifying patients of investigation results (not otherwise specified) | 1 (0.1) |
| Administrative | 170 (17.6) |
| Filing system | 95 (9.8) |
| Chart completeness and availability | 51 (5.3) |
| Patient flow | 6 (0.6) |
| Message handling | 1 (0.1) |
| Appointments | 17 (1.8) |
| Treatments | 17 (1.8) |
| Medication errors | 17 (1.8) |
| Communication | 55 (5.7) |
| Errors in communication with patients | 16 (1.7) |
| Communication with other providers sharing patient care | 26 (2.7) |
| Errors in communication between whole healthcare team | 13 (1.3) |
| Other process errors | 52 (5.4) |
| Building infrastructure or management errors | 5 (0.5) |
| Equipment | 32 (3.3) |
| Insurance-related errors | 8 (0.8) |
| Wrongly charged | 1 (0.1) |
| Workload management | 6 (0.6) |
| Knowledge and skills | 6 (0.6) |
| Failure to follow standard or recommended clinical procedure | 5 (0.5) |
| Failure to follow standard/recommended administrative practice | 1 (0.1) |
| Total | 966 (100.0) |