Performance of International Classification of Diseases, 9th Revision, Clinical Modification Codes as an Adverse Drug Event Surveillance System

Background:Adverse drug events (ADEs) are one of the most frequent causes of iatrogenic injury. Because International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) codes are routinely assigned to inpatient discharges, they could provide a method to detect ADEs within a hospital, a state, and the nation. Objective:The objective of this study was to determine validity of selected ICD-9-CM codes in identifying inpatient ADEs. Research Design:An expert panel identified 416 ICD-9-CM codes to represent ADEs (flagged ADE codes). Retrospective chart review using a structured tool was performed to ascertain code performance in detecting ADEs. Subjects:Subjects included 3103 inpatients from all 41 acute care hospitals in Utah in 2001: 1961 inpatients sampled randomly (random sample) and 1142 inpatients sampled from the discharge records with at least one flagged ADE code (flagged sample). Measures:Measures were ADEs identified by structured review. Results:The flagged sample yielded 1122 flagged ADE codes recorded in patient charts with 704 representing ADEs (63%). Two hundred eighty-six of the 704 verified ADE codes (41%) were determined to be inpatient ADEs. In the random sample, 32 of 58 ADEs (55%) causing hospital admission were detected by the ADE-flagged codes. Only 23 of 224 inpatient ADEs had been assigned a flagged ADE code (10%). Conclusions:Flagged ADE codes have an overall positive predictive value of 63% and detect just over half of ADEs causing hospital admission. These codes have a positive predictive value of 25% for inpatient ADEs but detect only 10% of overall inpatient ADEs. Flagged ADE codes provide an imperfect but immediately available ADE surveillance system.

[1]  S D Small,et al.  The incident reporting system does not detect adverse drug events: a problem for quality improvement. , 1995, The Joint Commission journal on quality improvement.

[2]  David W Bates,et al.  Medication errors observed in 36 health care facilities. , 2002, Archives of internal medicine.

[3]  D. Bates,et al.  The Costs of Adverse Drug Events in Hospitalized Patients , 1997 .

[4]  N M Laird,et al.  A study of medical injury and medical malpractice. , 1989, The New England journal of medicine.

[5]  T. Brennan,et al.  Incidence and types of adverse events and negligent care in Utah and Colorado. , 2000, Medical care.

[6]  T. Brennan,et al.  The nature of adverse events in hospitalized patients. Results of the Harvard Medical Practice Study II. , 1991, The New England journal of medicine.

[7]  A. Egberts,et al.  Adverse drug events in hospitalized patients A comparison of doctors, nurses and patients as sources of reports , 1999, European Journal of Clinical Pharmacology.

[8]  S D Small,et al.  The costs of adverse drug events in hospitalized patients. Adverse Drug Events Prevention Study Group. , 1998, JAMA.

[9]  D W Bates,et al.  Practical approach to determining costs and frequency of adverse drug events in a health care network. , 2001, American journal of health-system pharmacy : AJHP : official journal of the American Society of Health-System Pharmacists.

[10]  P. Loy.  International Classification of Diseases--9th revision. , 1978, Medical record and health care information journal.

[11]  M. Sager,et al.  Adverse drug events in hospitalized elderly. , 1998, The journals of gerontology. Series A, Biological sciences and medical sciences.

[12]  Jonathan M. Teich,et al.  Research Paper: Identifying Adverse Drug Events: Development of a Computer-based Monitor and Comparison with Chart Review and Stimulated Voluntary Report , 1998, J. Am. Medical Informatics Assoc..

[13]  P. Aspden.  Patient Safety: Achieving a New Standard for Care , 2004 .

[14]  J. Corrigan,et al.  COMMITTEE ON DATA STANDARDS FOR PATIENT SAFETY , 2004 .

[15]  Joshua Borus,et al.  Adverse drug events in ambulatory care. , 2003, The New England journal of medicine.

[16]  C M Ashton,et al.  International Classification of Diseases, 9th Revision, Clinical Modification codes in discharge abstracts are poor measures of complication occurrence in medical inpatients. , 1997, Medical care.

[17]  Rouett H. Abouzelof,et al.  Surveillance of medical device-related hazards and adverse events in hospitalized patients. , 2004 .

[18]  M. Scanlon,et al.  Computer physician order entry and the real world: we're only humans. , 2004, The Joint Commission Journal on Quality and Safety.

[19]  G. Kuperman,et al.  Computer Physician Order Entry: Benefits, Costs, and Issues , 2003, Annals of Internal Medicine.

[20]  Jeffrey Geppert,et al.  AHRQ Quality Indicators Guide to Patient Safety Indicators , 2003 .

[21]  M. Woloshynowych,et al.  Case record review of adverse events: a new approach , 2003, Quality & safety in health care.

[22]  D. Classen,et al.  Adverse drug events in hospitalized patients. Excess length of stay, extra costs, and attributable mortality. , 1997, JAMA.

[23]  Melissa M. Honour,et al.  Overcoming barriers to adopting and implementing computerized physician order entry systems in U.S. hospitals. , 2004, Health affairs.