Table 2

Harvard Medical Practice Study categories for classifying etiology of adverse events and medical errors, with three added categories for patient factors.
Code
 Type of Error
 Description
1
 Diagnostic
 Error in diagnosis or delay in diagnosis
2
 Diagnostic
 Failure to employ an indicated test
3
 Diagnostic
 Use of outmoded tests or therapy
4
 Diagnostic
 Failure to act on the results of monitoring or testing
5
 Treatment
 Technical error in performance of an operation, procedure, or test
6
 Treatment
 Error in administering the treatment (including preparation for operation or treatment)
7
 Treatment
 Error in dose of drug or in the method of use of a drug
8
 Treatment
 Avoidable delay in treatment or in responding to an abnormal test
9
 Treatment
 Inappropriate (not indicated) care. Considering the patient's disease, its severity, and comorbidity, the anticipated benefit from the treatment did not significantly exceed the known risk, or a superior alternative was available
10
 Preventive
 Failure to provide indicated prophylactic treatment
11
 Preventive'
 Inadequate monitoring or follow-up of treatment
12
 System
 Failure in communication
13
 System
 Equipment failure
14
 System
 Other systems failure
15
 Other
 Unclassified
*16
 No error
 Patient disease, expected risk



*17
 No error
 Patient non-compliance
*18
 No error
 Patient disease, unrelated to spinal surgery

*Additional three categories not included in the Harvard Medical Practice Study. We group these as "no error" simply to distinguish them from the evaluation and treatment associated factors under direct control of the medical care system. Alternatively, these three factors may be considered errors in patient selection.

Mirza et al. BMC Musculoskeletal Disorders 2006 7:53   doi:10.1186/1471-2474-7-53