Search tips
Search criteria 


Logo of nihpaAbout Author manuscriptsSubmit a manuscriptHHS Public Access; Author Manuscript; Accepted for publication in peer reviewed journal;
Ann Longterm Care. Author manuscript; available in PMC 2010 August 30.
Published in final edited form as:
Ann Longterm Care. 2010 May; 18(5): 17–22.
PMCID: PMC2929768

Detecting Adverse Drug Events Using a Nursing Home Specific Trigger Tool

Steven M. Handler, MD, MS, CMD, Assistant Professor1,2,3 and Joseph T. Hanlon, PharmD, MS, BCPS, Professor2,3,4,5

Adverse drug events (ADEs) are defined by the Institute of Medicine (IOM) as, “injuries resulting from a medical intervention related to a drug.”1 Institutionalized elderly experience ADEs at a rate as high as 10.8 events per 100-patient months, often as a result of polypharmacy, multiple comorbid illness, and difficulty with monitoring prescribed medications.24 This translates into approximately 135 ADEs each year in an average size nursing home (NH; bed size of 105) or approximately 2 million events a year among all U.S. NH patients. ADEs represent the most clinically significant and costly medication-related problems in NHs and are associated with 93,000 deaths a year and in as much as $4 billion of excess healthcare expenditures.56 Despite the consequences and costs associated with ADEs, the vast majority of these events go undetected using traditional methods including comprehensive chart reviews, direct observation, and voluntary reporting. Therefore, alternative surveillance strategies are needed in NHs to supplement existing detection strategies and minimize the potential consequences of ADEs.

The trigger tool methodology, developed in part by the Institute of Healthcare Improvement (IHI), greatly simplifies the chart review process by allowing rapid and systematic examination of charts to extract relevant data for the detection of potential ADEs. The technique, which requires minimal training, appears to increase the rate of ADE detection 50-fold from traditional reporting methods.7 The triggers themselves represent specific events including the ordering of certain medications (e.g., antidotes, such as Vitamin K), the results of certain laboratory studies (e.g., supratherapeutic serum medication concentrations, such as digoxin level), and change in clinical status or new sign or symptom (e.g., drug-induced fall or drug-related rash). Since the triggers are likely to differ based on specific clinical setting, multiple IHI trigger tools have been developed including those for: mental health settings, adult inpatient, adult outpatient, adult intensive care units, adult peri-operative care units, pediatric inpatient, and neonatal intensive care units.8 Many of the clinical setting-specific trigger tools have been successfully used to demonstrate the benefits of low-cost error detection strategies that produce consistent, reliable, and relevant data.913

Recently, a study was completed to develop a consensus list of agreed upon laboratory, pharmacy, and Minimum Data Set triggers to expand the use of the trigger tool methodology to the NH setting.14 The authors conducted a comprehensive literature search for potential ADE triggers, followed by an Internet-based, two-round, modified Delphi survey of physician, pharmacist, and advanced practitioner experts in geriatrics. Panelists reached consensus agreement on 40 triggers: 15 laboratory/medication combinations, 12 medication concentrations, 10 antidotes, and 3 Resident Assessment Protocols (RAPs). Highest consensus scores (4.6; 95% CI, 4.4–4.9 or 4.4–4.8) were for naloxone when taking opioid analgesics; phytonadione when taking warfarin; dextrose, glucagon, or liquid glucose when taking hypoglycemic agents; medication-induced hypoglycemia; supratherapeutic international normalized ratio when taking warfarin; and triggering the Falls RAP when taking certain medications.

The IHI formally adopted this set of 40 triggers as the “Nursing Home Adverse Drug Event Trigger Tool.”15 We suggest that this tool be incorporated into the consultant pharmacist medication regimen review (MRR) process. The State Operations Manual provides a definition for MRR (i.e., F428), as a thorough evaluation of the medication regimen of a resident, with goal of promoting positive outcomes and minimizing adverse consequences. The review includes preventing, identifying, reporting, and resolving medication errors, or other irregularities, and collaborating with other members of the interdisciplinary team.16 According to these new guidelines, F428 emphasizes that consultant pharmacists are expected to perform MRRs at least every 30 days, and expedited reviews for short-stay residents, as well as those residents who experience an acute change in condition.17

The IHI recommends either one of the two following strategies to detect triggers and investigate them to determine if an ADE has occurred: 1) review a sample of resident charts (letters A through I), or 2) review all resident charts (letters B through G):

  1. Select a random sample of 20 resident records.
  2. Obtain incident report information (e.g., medication error, adverse drug event, and falls reports) from the nursing home administrator, director of nursing, or risk management (if permissible).
  3. Review each resident record, paying particular attention to the following sections:
    1. Physician orders and Medication Administration Records (MARs): Look for trigger medications.
    2. Laboratory reports: Look for trigger lab results.
    3. Consultant pharmacist medication regimen review notes, consultations, and recommendations made to the attending physician. Look for previous recommendations made for monitoring, gradual dose reduction, or to stop drug, change drug, change dose, change directions, change schedule, or other (e.g., add a drug, change formulation).
    4. Physician and nursing progress notes looking for acute or gradual change in condition such as new or worsening cognitive or functional status, falls, lethargy, gastrointestinal problems, hypotension, rash, nausea/vomiting, or other adverse events that may be associated with the use of a medication. Also, take note of any unplanned hospitalization and emergency department evaluations.
  4. List all triggers found on the ADE Resident Record Review Sheet (Table 1).
    Table 1
    Trigger Tool for Measuring Adverse Drug Events in the Nursing Home
  5. For each trigger found, read through the appropriate parts of the resident record to determine if an ADE has occurred. Sometimes professional judgment will be required to make this determination. Some ADEs will result in more than one trigger; use your best judgment in determining the number of ADEs that occurred in this situation.
  6. If an ADE occurred, assign a category of harm (E through I) and provide a brief description of the ADE (Table 1).
  7. After you have completed the ADE Patient Record Review Sheet for the patient records in the sample, summarize your findings in the ADE Monthly Summary Sheet (Table 2). For each patient record reviewed, document the following: whether an ADE occurred; the number of ADEs; and (if you collected data on doses) the total number of medication doses received.
    Table 2
    ADE Monthly Summary Sheet
  8. Use the data in the ADE Monthly Summary Sheet to calculate one or both of these important measures:
    1. Percent of residents with an ADE
      1. The total number residents identified as having experienced any ADEs from a sample of resident records, divided by the total number of records in the sample; multiplied by 100 to express as a percentage.
    2. ADEs per 1,000 Doses
      1. The total number of ADEs identified in a sample of resident records, divided by the total number of medication doses administered to those residents. Multiply the result by 1,000.
  9. Track the measures (Percent of Admissions with an ADE, ADEs per 1,000 Doses) over time in a run chart, to see if changes you are testing are making the medication system safer. You can use the Improvement Tracker on to automatically track and graph these measures over time.

The IHI recommends using the results of this tool to measure the number of ADEs in an organization over time, and determine whether or not the changes a facility is making results in improvement. Similar to other NH quality improvement initiatives, the results can be summarized and reported to the quality assessment and assurance (QAA) committee that is required to meet at least quarterly as described in F520.18 During these meetings, the committee can develop and implement plans of action to correct the future occurrence of ADEs, including monitoring the effect of implemented changes and making needed revisions to the action plans.

The future of ADE detection in the NH setting will likely rely on utilizing health information technology. This is consistent with the IOM and other patient safety organizations recommendation that all healthcare settings assess the safety of medication use through active monitoring systems within a culture of safety.1, 1622 Although most NHs have yet to adopt a significant amount of health information technology23, the majority generate laboratory, pharmacy, and Minimum Data Set data in electronic format that can be used by active medication monitoring systems to automate the detection of ADEs. Recently, investigators have developed and tested an active medication monitoring system using the consensus set of NH triggers accepted by IHI.24 They found that they could detect ADEs with a high degree of accuracy and at a rate of nearly 2.5 times greater than that of usual care (i.e., pharmacist-conducted manual chart review).

Table thumbnail


1. Institute of Medicine. Preventing Medication Errors. Washington, DC: National Academies Press; 2007.
2. Handler SM, Wright RM, Ruby CM, Hanlon JT. Epidemiology of medication-related adverse events in nursing homes. Am J Geriatr Pharmacother. 2006 Sep;4(3):264–272. [PubMed]
3. Gurwitz JH, Field TS, Avorn J, McCormick D, Jain S, Eckler M, et al. Incidence and preventability of adverse drug events in nursing homes. Am J Med. 2000;109(2):87–94. [PubMed]
4. Gurwitz JH, Field TS, Judge J, Rochon P, Harrold LR, Cadoret C, et al. The incidence of adverse drug events in two large academic long-term care facilities. Am J Med. 2005 Mar;118(3):251–258. [PubMed]
5. Bootman JL, Harrison DL, Cox E. The health care cost of drug-related morbidity and mortality in nursing facilities. Arch Intern Med. 1997;157(18):2089–2096. [PubMed]
6. Gurwitz JH, Field TS, Rochon P, Judge J, Harrold LR, Bell CM, et al. Effect of computerized provider order entry with clinical decision support on adverse drug events in the long-term care setting. J Am Geriatr Soc. 2008;56(12):2225–2233. [PubMed]
7. Cohen MR, editor. Medication Errors. Washington, DC: American Pharmacists Association; 2007. [PubMed]
8. Institute for Healthcare Improvement. Trigger Tool for Measuring Adverse Drug Events (IHI Tool) [Accessed August 17, 2009].
9. Resar RK, Rozich JD, Classen D. Methodology and rationale for the measurement of harm with trigger tools. Qual Saf Health Care. 2003 Dec;12(Suppl 2):ii39–45. [PMC free article] [PubMed]
10. Rozich JD, Haraden CR, Resar RK. Adverse drug event trigger tool: a practical methodology for measuring medication related harm. Qual Saf Health Care. 2003 Jun;12(3):194–200. [PMC free article] [PubMed]
11. Takata GS, Mason W, Taketomo C, Logsdon T, Sharek PJ. Development, testing, and findings of a pediatric-focused trigger tool to identify medication-related harm in US children's hospitals. Pediatrics. 2008 Apr;121(4):e927–935. [PubMed]
12. Cohen MM, Kimmel NL, Benage MK, Cox MJ, Sanders N, Spence D, et al. Medication safety program reduces adverse drug events in a community hospital. Qual Saf Health Care. 2005 Jun;14(3):169–174. [PMC free article] [PubMed]
13. Sharek PJ, Horbar JD, Mason W, Bisarya H, Thurm CW, Suresh G, et al. Adverse events in the neonatal intensive care unit: development, testing, and findings of an NICU-focused trigger tool to identify harm in North American NICUs. Pediatrics. 2006 Oct;118(4):1332–1340. [PubMed]
14. Handler SM, Hanlon JT, Perera S, Roumani YF, Nace DA, Fridsma DB, et al. Consensus list of signals to detect potential adverse drug reactions in nursing homes. J Am Geriatr Soc. 2008 May;56(5):808–815. [PMC free article] [PubMed]
15. Institute for Healthcare Improvement. Trigger Tool for Measuring Adverse Drug Events in the Nursing Home. [Accessed August 17, 2009].
16. Martin CM, McSpadden CS. Changes in the state operations manual: implications for consultant pharmacy practice. Consult Pharm. 2006 Dec;21(12):948–961. [PubMed]
17. Bain KT. Adverse drug reactions and current state of drug regimen review in nursing facilities: need for a change? Consult Pharm. 2007 Jul;22(7):586–592. [PubMed]
18. U.S. Department of Health and Human Services and Centers for Medicare & Medicaid Services. Guidance to surveyors for long term care facilities. State Operations Provider Certification. [Accessed September 10, 2008].
19. National Quality Forum. Safe Practices for Better Healthcare: A Consensus Report. 2003.
20. Institute of Medicine. Patient Safety: Achieving a New Standard for Care. Washington, D.C: The National Academies Press; 2004.
21. Shojania KG, Duncan BW, McDonald KM, Watchter RM. Making Health Care Safer: A Critical Analysis of Patient Safety Practices. Rockville, MD: Agency for Healthcare Research and Quality; 2001. p. 43. [PubMed]
22. Kilbridge PM, Classen DC. Automated surveillance for adverse events in hospitalized patients: back to the future. Qual Saf Health Care. 2006 Jun;15(3):148–149. [PMC free article] [PubMed]
23. Alexander GL, Wakefield DS. Information technology sophistication in nursing homes. J Am Med Dir Assoc. 2009 Jul;10(6):398–407. [PMC free article] [PubMed]
24. Handler SM, Hanlon JT, Perera S, Saul MI, Fridsma DB, Visweswaran S, et al. Assessing the Performance Characteristics of Signals Used by a Clinical Event Monitor to Detect Adverse Drug Reactions in the Nursing Home. Proceedings / AMIA. 2008:278–282. [PMC free article] [PubMed]