Measuring Up to Medication Safety
Medications are among the most common interventions used to improve health. So it should come as no surprise that adverse drug events – injuries caused by the use of medications – are a substantial source of preventable harm to hospitalized patients. Measuring the level of safety is fundamental to improvement. Yet, measuring medication safety has long been a conundrum. Historically, measurement efforts have focused on practitioner reporting of medication errors, which, at best, uncovers just a fraction of the errors, most of them harmless. Still, measurement is the only way to answer these essential questions:
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Do we have a problem?
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What is the extent of the problem?
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Have improvement efforts been successful?
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How do we compare to others?
There are four types of measures that should be tracked if you want to improve medication safety.
Process measures. These measures help assess how well you are performing core processes associated with medication use. Measuring core processes helps determine if there is variation in carrying them out, which could lead to undesirable outcomes, and if there are preventable risks associated with processes, which could result in harm. Process measures can be identified for all facets of medication use. However, high-volume and high-risk processes, or processes associated with high-alert medications, should be targeted to maximize the benefit to patient safety. A few examples include:
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Number of pharmacy profiles without allergy information per new admission orders
- Percent of medication orders with prohibited error-prone abbreviations
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Percent of encounters in which two identifiers are not used for patient verification before drug administration
- Time interval between prescribing and administering “stat” medications
- Number of pharmacy interventions per 100 admissions
- Percent of chemotherapy orders that do not comply with standardized prescribing guidelines (e.g., mg/m2 dose included with calculated dose; single daily dose, not course dose).
One newly evolving measure to evaluate improvement within a process is to track the total risk priority number (RPN) of a process that has undergone a failure mode and effects analysis. As an organization works to improve the process, the RPN should decrease over time as effective changes are implemented. For more information on this process measure, click here.
Structure measures. These measures assess the organizational culture, values, and leadership. They differ from process measures in that they are not task oriented, but foundational in nature. Examples include:
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Percent of days on which pre-established nurse/patient staffing ratios are maintained
- Percent of staffing met with agency staff
- Number of error reports received (reporting rate helps measure the culture)
- Percent of staff reporting a positive safety culture.
Outcome measures. These measures assess whether your efforts to improve medication safety have been successful. As such, many believe that medication errors are the most useful outcome measure for medication safety. However, harm is a much more reliable and powerful measure, especially if it keeps you intellectually engaged with the possibility that all harm is preventable.
If errors are used to measure medication safety, self-reporting is the typical data-gathering tool, which is highly inaccurate. Errors are the obvious focus, so any adverse drug events uncovered are quickly sorted into preventable and “non-preventable” categories. This, in turn, promotes the tacit acceptance of “non-preventable” harm as a property of the medication system, something for which you have no responsibility. On the other hand, if harm is used as a measure of medication safety, the measure is reliable, clear, and direct, and the focus is on all unintended results. This keeps you intellectually engaged with the possibility of reducing all patient harm, to admit that you can do better, to raise the bar when it comes to patient safety. For example, most hospitals collect data on readmissions to the hospital. If bleeding episodes from warfarin caused some of the readmissions, these events may not be fully assessed if the focus is on errors alone. In these cases, errors may not be apparent, so the events would likely be tagged as “non-preventable” adverse drug reactions. But if focused only on preventing harm in patients who take warfarin, not error, you’re more likely to explore ways to reduce all occurrences of bleeding. Thus, the best outcome measure for medication safety is all adverse drug events, regardless of causation.
Evaluating patient records using a list of triggers is the most effective means of collecting data on adverse drug events. Triggers are clues that an adverse drug event may have occurred. Follow up is needed for confirmation. An extensive list of triggers can be found in Table 1.
Examples include:
- Drugs: diphenhydramine, vitamin K, flumazenil, glucagon
- Labs: elevated drug levels, aPTT, INR, serum creatinine
- Others: rash, lethargy, falls, abrupt medication stop, transfer to a higher level of care.
Computerized methods for detecting adverse drug events via a trigger tool have proved very effective.1 However, this methodology requires a high level of automation with customized software linkage to clinical databases, so the initial outlay may be costly. However, recently, a relatively low cost, “low tech” method for using a trigger tool to uncover adverse drug events has been devised and tested in more than 80 hospitals.2 The technique, which requires minimal training, appears to increase the rate of adverse drug event detection 50-fold over traditional reporting methodologies.
Balancing measures. These measures are used to ensure that a change in one part of the system is not causing problems in another part of the system. For example, by using balancing measures, one hospital quickly learned that a change in antiemetics to reduce the time a patient must spend in the oncology clinic actually resulted in reduced patient satisfaction. Patients felt rushed and unable to talk to staff about their diagnosis and therapy.
Measuring medication safety is not easy, but it must be a core component of your improvement efforts. If you do not have an effective measurement plan in place, an interdisciplinary team should consider the examples above and identify a place to start. Be sure to clearly describe each measure, its goal, and the data collection plan. Remember: traditional efforts to measure medication safety have not been successful in guiding improvement. Thus, even if you currently have a measurement plan in place, it may be time to look at it again with fresh eyes and updated tools.
Causal Medication | Trigger | Potential ADE |
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Amikacin | Serum amikacin greater than 35 mcg/mL | Toxic amikacin level |
Antibiotics | Positive stool cultures for C. diff | C. difficile infection |
Antibiotics | Anti-diarrheals | C. difficile infection |
Antibiotics | Metronidazole (oral) | C. difficile infection |
Antibiotics | Vancomycin (oral) | C. difficile infection |
Antibiotics | Clotrimazole troches | Thrush |
Antibiotics | Nystatin oral suspension | Thrush |
Anticholinergic medications, belladonna alkaloids | Physostigmine | Anticholineric overdose, belladonna alkaloids overdose |
Antidepressants, antipsychotics, local anesthetics, etc. | Phenytoin | Seizures, arrhythmias |
Antidepressants, antipsychotics, local anesthetics, etc. | Lorezepam | Seizures |
Antidepressants, antipsychotics, local anesthetics, etc. | Phenobarbital | Seizures |
Antifungals | Antifungal use and increasing serum creatinine | Renal insufficiency |
Anti-hypertensives | Atropine | Bradycardia |
Antipsychotics | Benztropine | Extrapyramidal reactions |
Antipsychotics | Dantrolene | Hyperthermia, neuroleptic malignant syndrome |
Antivirals | Antifungal use and increasing serum creatinine | Renal insufficience |
Benzodiazepines | Flumazenil | Oversedation with benzodiazepine |
Beta-blockers | Beta-blocker use and triamcinolone | Rash |
Carbamazepine | Serum carbamazepine greater than 12 mcg/ML | Toxic carbamazepine level |
Cyclosporine | Serum cyclosporine greater than 500 mcg/L | Toxic cyclosporine level |
Digoxin | Serum digoxin level greater than 2 ng/mL | Toxic digoxin level |
Digoxin | Digoxin immune fab (Digibind) | Toxic digoxin level |
Digoxin | Digozin use and increasing creatinine | Renal insufficiency |
Digoxin and amiodarone | Digoxin and amiodarone use | Medication interaction leading to digoxin toxicity |
Dopamine | Nitroglycerin | Dopamine extravasation |
Dopamine | Phentolamine | Dopamine extravasation |
Enoxaparin | Enoxaparin use and increasing creatinine | Renal insufficiency |
Flouroquinonlones | Flouroquinolone use and increasing creatinine | Renal insufficiency |
Gentamicin | Serum gentamicin greater than 10 mg/L | Toxic gentamicin level |
Heparin | Protamine | Heparin overdose |
Heparin | Danaparoid and lepirudin | Heparin-induced thrombocytopenia |
Heparin | PTT greater than 100 seconds | Excessive anticoagulation with heparin |
Heparin, ranitidine, NSAIDs, etc. | Platelet count less than 50,000 | Drug-induced thrombocytopenia |
Injectable chemotherapeutic agents | Dimethyl Sulfoxide (DMSO) | Chemotherapy extravasation |
Injectable chemotherapeutic agents | Hyaluronidase | Chemotherapy extravasation |
Insulin, other hypoglycemic agents | Dextose 50% in water | Hypoglycemia |
Insulin, other hypoglycemic agents | Glucagon | Hypoglycemia |
Insulin, other hypoglycemic agents | Serum glucose (less than 50) | Hypoglycemia |
Lidocaine | Serum lidocaine greater than 5 mcg/mL | Toxic lidocaine level |
Meperidine, other medications | Diazepam | Seizures |
Metformin | Metformin use and increasing creatinine | Hepatic insufficiency |
Miscellaneous | Hydroxyzine | Hypersensitivity reaction or drug rash |
Miscellaneous | Abrupt stop of a medication order | ADE |
Miscellaneous | Transfer to a higher level of care | Change in clinical condition |
Miscellaneous | Methylprednisolone | Hypersensitivity reaction |
Miscellaneous | Droperidol | Nausea/emesis |
Miscellaneous | Fosphenytoin | Seizures/arrhythmias |
Miscellaneous | Rising serum creatinine | Renal insufficiency |
Miscellaneous | Calamine lotion | Rash |
Miscellaneous | Blood eosinophils greater than 6% | Eosinophilia related to hypersensitivity reaction |
Miscellaneous | Diprolene 0.05% | Rash |
Miscellaneous | Rash | Hypersensitivity reaction |
Miscellaneous | Anti-emetics | Medication toxicity or overdose |
Miscellaneous | Charcoal (activated) | Medication overdose |
Miscellaneous | WBC count less than 3,000 | Leukopenia related to non-chemotherapy medication |
Miscellaneous | Antihistamines | Hypersensitivity reactions, drug rash |
Miscellaneous | Diphenhydramine | Hypersensitivity reactions, drug rash, extrapyramidal reaction |
Miscellaneous | Steroids (topical) | Hypersensitivity reactions, drug rash |
Miscellaneous | Steroids (injectable) | Hypersensitivity reactions |
Miscellaneous | Epinephrine | Hypersensitivity reactions |
Miscellaneous | Topical corticosteroids | Rash |
Miscellaneous 1 | Calcium chloride | Hypocalcemia |
Miscellaneous 1 | Calcium gluconate | Hypocalcemia |
Miscellaneous 2 | Hepatotoxic medications and increasing ALT (20%) | Hepatic insufficiency |
Miscellaneous 2 | Serum ALT greater than 150 Units/L | Hepatic insufficiency |
Miscellaneous 2 | Serum bilirubin greater than 10 mg/dL | Hepatic insufficiency |
Miscellaneous 2 | Hepatotoxic medications and increasing AST (20%0 | Hepatic insufficiency |
Miscellaneous 3 | Potassium sliding scale and creatinine greater than 2 | Renal insufficiency |
Miscellaneous 3 | Magnesium sliding scale and creatinine greater than 2 | Renal insufficiency |
Miscellaneous 4 | Absolute reticulocyte count greater than 2% | Hemolytic anemia |
NSAIDS | Blood transfusions | NSAID-induced gastric bleeds |
Opiates | Naloxone | Narcotic overdose |
Opiates | Combination of 3 or more narcotics ordered | Opiate-related side effects |
Opium tincture (mistaken for paregoric) | Opium tincture deodorized | Wrong drug error (confusion with paregoric) |
Phenytoin | Serum phenytoin levels greater than 20 mcg/mL | Toxic phenytoin level |
Potassium, misc. | Serum potassium greater than 6.5 mmol/L | Hyperkalemia due to renal insufficiency or drug effect |
Potassium, misc. | Sodium polystyrene sulfonate (Kayexalate) | Hyperkalemia due to renal impairment or drug effect |
Procainamide | Serum procainamide greater than 10 mcg/mL | Toxic procainamide level |
Quinidine | Serum quinidine greater than 5 mcg/mL | Toxic quinidine level |
Ranitidine | Ranitidine use and creatinine greater than 2 | Renal insufficiency |
Sedatives, analgesics, muscle relaxants | Patient fall | ADE related to use of a sedative, analgesic, or muscle relaxant |
Sedatives, analgesics, nueromuscular blockers | Intubation or respiratory arrest | Respiratory depression or aspiration |
Theophylline | Serum theophylline greater than 20 mcg/mL | Toxic theophylline level |
Tobramycin | Serum tobramycin greater than 10 mg/L | Toxic tobramycin level |
Toxic phenytoin level | Phenytoin level greater than 18 and albumin less than 3.3 | Phenytoin overdoes |
Valproic acid | Serum valproate greater than 120 mcg/mL | Toxic valproic acid level |
Vancomycin | Vancomycin (IV) and increasing creatinine | Renal insufficiency |
Vancomycin | Serum vancomycin greater than 50 mg/L | Toxic vancomycin level |
Warfarin | Phytonadoine | Warfarin overdose |
Warfarin | INR greater than 6 | Excessive anticoagulation with warfarin |
- Some medications that can cause hypocalcemia: Foscarnet, phosphate infusion, infusion of citrated blood products, contrast agents containing EDTA
- Some medications that can cause hepatic toxicity: Lipid-lowering agents, NSAIDS, antidiabetic agents (pioglitazone, acarbose, sulfonylureas), antibiotics, antifungals
- Some medications that can cause renal toxicity: aminoglycosides, angiotensin converting enzyme (ACE) inhibitors, acyclovir, amphotericin B, carboplatin, cisplatin, cyclosporine, foscarnet, ifosfamide, metformin, nonsteroidal anti-inflammatory agents
- Some medications that can cause hemolytic anemia: penicillins, cephalosporins, levodopa, methyldopa, mefenamic acid, quinidine, salicylic acid, sulfonamides, Thiazide diuretics, antazoline, chlorpromazine, isoniazid, streptomycin, ibuprofen
Article References:
- Classen DC, Metzger J. Improving medication safety: the measurement conundrum and where to start. Internat Jour for Qual in Health Care 2003; 15:i41-i47
- Rozich JD, Haraden CR, Resar RK. Adverse drug event trigger tool: a practical methodology for measuring medication related harm. Qual Saf Health Care 2003; 12;194-200
Trigger List References:
- Classen DC, Pestotnik SL, Evans RS, Burke JP. Computerized Surveillance of Adverse Drug Events in Hospital Patients. JAMA; Nov 27, 1991;266(20):2847-51.
- Jha AK, Kuperman GJ, Teich JM, et al. Identifying Adverse Drug Events: Development of a Computer-based Monitor and Comparison with Chart Review and Stimulated Voluntary Report. JAMIA; May/Jun 1998;5(3):305-14.
- Riedl MA, Casillas AM. Adverse Drug Reactions: Types and Treatment Options. Am Fam Physician;Nov 1, 2003;68(9):1781-90.
- Rozich JD, Resar RK. Adverse drug event trigger tool: a practical methodology for measuring medication related harm. Qual Saf Health Care 2003;12:194-200.
- Silverman JB, Stapinski CD, Huber C, et al. Computer-based system for preventing adverse drug events. Am J Health-Syst Pharm;Aug 1, 2004;61:1599-603.
- Winterstein AG, Hatton RC, Gonzalez-Rothi R, et al. Identifying Clinically Significant Preventable Adverse Drug Events Through a Database of Adverse Drug Reaction Reports. Am J Health-Syst Pharm;2002;59(18):1742-9.