Missed and Delayed Diagnoses in the Ambulatory Setting: A Study of Closed Malpractice Claims

3 October 2006 | Volume 145 Issue 7 | Pages 488-496

Background: Although missed and delayed diagnoses have become an important patient safety concern, they remain largely unstudied, especially in the outpatient setting.

Objective: To develop a framework for investigating missed and delayed diagnoses, advance understanding of their causes, and identify opportunities for prevention.

Design: Retrospective review of 307 closed malpractice claims in which patients alleged a missed or delayed diagnosis in the ambulatory setting.

Setting: 4 malpractice insurance companies.

Measurements: Diagnostic errors associated with adverse outcomes for patients, process breakdowns, and contributing factors.

Results: A total of 181 claims (59%) involved diagnostic errors that harmed patients. Fifty-nine percent (106 of 181) of these errors were associated with serious harm, and 30% (55 of 181) resulted in death. For 59% (106 of 181) of the errors, cancer was the diagnosis involved, chiefly breast (44 claims [24%]) and colorectal (13 claims [7%]) cancer. The most common breakdowns in the diagnostic process were failure to order an appropriate diagnostic test (100 of 181 [55%]), failure to create a proper follow-up plan (81 of 181 [45%]), failure to obtain an adequate history or perform an adequate physical examination (76 of 181 [42%]), and incorrect interpretation of diagnostic tests (67 of 181 [37%]). The leading factors that contributed to the errors were failures in judgment (143 of 181 [79%]), vigilance or memory (106 of 181 [59%]), knowledge (86 of 181 [48%]), patient-related factors (84 of 181 [46%]), and handoffs (36 of 181 [20%]). The median number of process breakdowns and contributing factors per error was 3 for both (interquartile range, 2 to 4).

Limitations: Reviewers were not blinded to the litigation outcomes, and the reliability of the error determination was moderate.

Conclusions: Diagnostic errors that harm patients are typically the result of multiple breakdowns and individual and system factors. Awareness of the most common types of breakdowns and factors could help efforts to identify and prioritize strategies to prevent diagnostic errors.

Editors' Notes Context Efforts to reduce medical errors and improve patient safety have not generally addressed errors in diagnosis. As with treatment, diagnosis involves complex, fragmented processes within health care systems that are vulnerable to failures and breakdowns. Contributions The authors reviewed malpractice claims alleging injury from a missed or delayed diagnosis. In 181 cases in which there was a high likelihood that error led to the missed diagnosis, the authors analyzed where the diagnostic process broke down and why. The most common missed diagnosis was cancer, and the most common breakdowns were failure to order appropriate tests and inadequate follow-up of test results. A median of 3 process breakdowns occurred per error, and 2 or more clinicians were involved in 43% of cases. Cautions The study relied on malpractice claims, which are not representative of all diagnostic errors that occur. There was only moderate agreement among the authors in their subjective judgments about errors and their causes. Implications Like other medical errors, diagnostic errors are multifactorial. They arise from multiple process breakdowns, usually involving multiple providers. The results highlight the challenge of finding effective ways to reduce diagnostic errors as a component of improving health care quality. —The Editors

 

Author and Article Information

From Brigham and Women's Hospital and Harvard School of Public Health, Boston, Massachusetts; University of Texas Health Science Center, Houston, Texas; and the Harvard Risk Management Foundation, Cambridge, Massachusetts.

Note: Drs. Gandhi, Kachalia, and Studdert had full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.

Grant Support: This study was supported by grants from the Agency for Healthcare Research and Quality (HS011886-03) and the Harvard Risk Management Foundation. Dr. Studdert was also supported by the Agency for Healthcare Research and Quality (KO2HS11285).

Potential Financial Conflicts of Interest:Employment: T.A. Brennan (Aetna); Stock ownership or options (other than mutual funds): T.A. Brennan (Aetna); Expert testimony: T.A. Brennan.

Requests for Single Reprints: David M. Studdert, LLB, ScD, Department of Health Policy and Management, Harvard School of Public Health, 677 Huntington Avenue, Boston, MA 02115; e-mail, studdert{at}hsph.harvard.edu.

Current Author Addresses: Drs. Gandhi and Kachalia and Ms. Yoon: Division of General Internal Medicine, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02114.

Dr. Thomas: University of Texas Medical School at Houston, 6431 Fannin, MSB 1.122, Houston, TX 77030.

Ms. Puopolo: CRICO/RMF, 101 Main Street, Cambridge, MA 02142.

Dr. Brennan: 151 Farmington Avenue, RC5A, Hartford, CT 06156.

Dr. Studdert: Harvard School of Public Health, 677 Huntington Avenue, Boston, MA 02115.

Author Contributions: Conception and design: T.K. Gandhi, E.J. Thomas, T.A. Brennan, D.M. Studdert.

Analysis and interpretation of the data: T.K. Gandhi, A. Kachalia, C. Yoon, D.M. Studdert.

Drafting of the article: T.K. Gandhi, A. Kachalia, T.A. Brennan D.M. Studdert.

Critical revision of the article for important intellectual content: T.K. Gandhi, A. Kachalia, E.J. Thomas, T.A. Brennan D.M. Studdert.

Final approval of the article: T.K. Gandhi, A. Kachalia, E.J. Thomas, D.M. Studdert.

Provision of study materials or patients: A.L. Puopolo.

Statistical expertise: D.M. Studdert.

Obtaining of funding: D.M. Studdert.

Administrative, technical, or logistic support: A. Kachalia, A.L. Puopolo, D.M. Studdert.

Collection and assembly of data: A. Kachalia, A.L. Puopolo, D.M. Studdert.

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