Original Research

Classification of medical errors and preventable adverse events in primary care: A synthesis of the literature

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The purpose of this study was to use published data from original research to understand and classify process errors and preventable adverse events associated with primary medical care. Through a systematic review and synthesis of the medical literature, we developed a classification of medical errors relevant to primary care.


To identify eligible published English-language original research articles, we searched MEDLINE and the Cochrane Library from 1965 through March 2001 with the MESH search term medical errors, modified by adding family practice, primary health care, physicians/family, or ambulatory care to the primary term. Published bibliographies from the National Patient Safety Foundation (NPSF) and the Institute for Healthcare Improvement (IHI) were also reviewed. The Web sites of the American Academy of Family Physicians, the American College of Physicians–American Society of Internal Medicine, the Institute of Medicine, the NPSF, and the IHI were also reviewed for unpublished reports, presentations, and leads to other sites, journals, or investigators with relevant work. Additional papers were identified from the references of the papers reviewed, from seminal papers in the field, and from discussion with others working in the field of patient safety or quality improvement in primary care.

We reviewed titles of 379 articles identified by electronic searches for inclusion. We excluded papers if they related to comparisons of different approaches to diagnosis or treatment of specific diseases, the evaluation of teaching or research tools, or exclusively to hospitalized patients. If there was uncertainty as to the appropriateness of an article, we read the abstract. We reviewed complete papers if they appeared from the title and abstract to report original research involving a broad assessment of medical errors and preventable adverse events in primary care. Data relating to topic, study quality, and research results were abstracted from identified papers. Both authors performed independent MEDLINE searches and reviewed citations in the papers. To broaden the search for potential studies, one author searched Web sites and NPSF and IHI bibliographies. Both authors agreed on the inclusion of the chosen studies, appraised them independently, and abstracted key classification components. One author (N.C.E.) initially prepared the classification system presented here; it was then reviewed by both authors and revised after their discussions.


Four original research studies directly studied and described medical errors and preventable adverse events in primary care.10-13 Three other studies peripherally addressed primary care medical errors as part of an investigation with another central focus14-16 (Table 1).

Primary care studies describing medical error

StudyResearch purposeDefinition of errorMethodPertinent results
Primary care studies directly describing medical error
Bhasale et al10Describe incidents occurring in general practiceAn unintended event, no matter how seemingly trivial or commonplace, that could have harmed or did harm a patientSelf-report by 324 Australian sentinel research network FPs using reporting cards805 incidents reported, 76% preventable; categories were drug management, non-drug management, diagnosis, and equipment; causes included communication, actions of others, and clinical judgment errors
Ely et al12Describe the causes to which family physicians attribute errorsAct or omission for which the physician felt responsible and which had serious consequences for the patient30-min interviews with 53 randomly chosen Iowa FPs53 errors reported: delayed diagnoses, surgical and medical treatment mishaps; causes included physical stressors, process of care factors, patient related factors, and physician characteristics
Dovey et al11Describe medical errors reported by FPsSomething in one’s practice that should not have happened, that was not anticipated, and that makes one say, “I don’t want it to happen again”Self-report by 42 American research network FPs using electronic and reply card reporting330 reported errors, 83% from health care system and 13% from knowledge and skills; subcategories were office administration, investigations, treatments, communication, execution of clinical tasks, misdiagnosis, and wrong treatment decision
Fischer et al13Describe the prevalence of adverse events in a risk management databaseIncidents resulting in, or having the potential for, physical, emotional, or financial liability for the patientReview of incident reports entered by 8 primary care clinics into risk management databasePrevalence of adverse events was 3.7/100,000 clinic visits, 83% were preventable; categories included diagnostic, treatment, and preventive and other errors
Primary care studies peripherally describing medical error
Holden et al15Determine patterns of death and potential preventive factors Formal review of all patient deaths in a group of general practices5.1% of deaths due to preventable FP factors; 2 main categories were delay of diagnosis and treatment and lack of prevention with aspirin therapy
Gandhi et al14communicationEvaluate primary care and specialist inter physician Surveys in academic medical centerMain issues for doctors were lack of timeliness and inadequate content
Britten et al16Describe misunderstandings between patients and FPs Qualitative study using 5 data sources14 categories of misunderstandings were identified
FP, family physician.

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