Classifying and Predicting Errors of Inpatient Medication Reconciliation

Abstract

Background

Failure to reconcile medications across transitions in care is an important source of potential harm to patients. Little is known about the predictors of unintentional medication discrepancies and how, when, and where they occur.

Objective

To determine the reasons, timing, and predictors of potentially harmful medication discrepancies.

Design

Prospective observational study.

Patients

Admitted general medical patients.

Measurements

Study pharmacists took gold-standard medication histories and compared them with medical teams’ medication histories, admission and discharge orders. Blinded teams of physicians adjudicated all unexplained discrepancies using a modification of an existing typology. The main outcome was the number of potentially harmful unintentional medication discrepancies per patient (potential adverse drug events or PADEs).

Results

Among 180 patients, 2066 medication discrepancies were identified, and 257 (12%) were unintentional and had potential for harm (1.4 per patient). Of these, 186 (72%) were due to errors taking the preadmission medication history, while 68 (26%) were due to errors reconciling the medication history with discharge orders. Most PADEs occurred at discharge (75%). In multivariable analyses, low patient understanding of preadmission medications, number of medication changes from preadmission to discharge, and medication history taken by an intern were associated with PADEs.

Conclusions

Unintentional medication discrepancies are common and more often due to errors taking an accurate medication history than errors reconciling this history with patient orders. Focusing on accurate medication histories, on potential medication errors at discharge, and on identifying high-risk patients for more intensive interventions may improve medication safety during and after hospitalization.

Appendices

Appendix 1: Protocol for Collecting Gold Standard Medication History

• 1. Who: Study pharmacist

• 2. When: As soon after admission as possible

• 3. Use all available sources:

  • a. Patient (introduce yourself, get informal consent)

  • b. Family

  • c. Have someone bring in pill bottles and/or med lists from home, review with patient/family.

  • d. Available outpatient electronic medical records (EMRs)

  • e. Previous discharge summaries

  • f. Primary care providers (PCPs) or other doctor’s office

  • g. Community pharmacy

• 4. Time-saving tips

  • a. Review previous discharge summaries only if there is one from the previous year, unless there is no information in the available outpatient EMRs (in which case look at older discharge summaries).

  • b. In outpatient EMRs, if last note is comprehensive, then no need to look at previous notes.

  • c. In outpatient EMRs, just scan lists of inactive meds and non-meds, but don’t spend a lot of time on them. Focus on lists of active medications.

• 5. Begin by gathering all easily accessible sources: outpatient EMR medication lists, hospital discharge summaries, transfer orders, and physician’s admission note.

• 6. When reviewing these data sources with the patient/family, specifically ask about differences among these different lists and clarify what the patient is actually taking.

• 7. Encourage patients to use more than just their memory, i.e., use a paper list, pill bottles, etc.

• 8. If patients use a list or pill bottles and seem completely reliable (and the data are not that dissimilar from the other sources, and differences can be explained), then other sources are not needed.

• 9. If patients are not sure or are relying on memory only, or cannot clearly “clean up” the other sources of medication information, then it’s time to rely on other sources: community pharmacies, outpatient physician offices, having the family bring in pill bottles, etc.

• 10. Pill bottles, reviewed with patient/family, are preferable to pharmacist refill information if available and if the review with patient/family seems reliable.

• 11. It is not enough to rely on the physician’s preadmission medication list as the main source of additional information.

• 12. Use an interpreter with non-English speaking patients unless you are fluent in the other language.

• 13. How to document non-adherence:

  • a. If completely non-adherent (on purpose or because didn’t know to take medication), then leave off list and note it in general comments.

  • b. If sporadically non-adherent, give general assessment of adherence in comments.

  • c. If systematically non-adherent (e.g., always takes medicine once a day instead of 3 times a day), then note actual frequency taken in dose/route/frequency section and make note of discrepancy from prescribed frequency in comments.

• 14. If patient denies knowledge of a medication that is on another list (i.e., doesn’t know why not taking it), keep track of these in comments. If these occur often, you will need to call the PCP’s office to see if the patient is really supposed to be on it.

Appendix 2: Potential ADE Adjudication Instructions

• I. Overview of medication discrepancies

  • a. Definition: any difference between medications taken by a patient prior to admission and medications ordered in the hospital

  • b. Typology:

    • i. Intentional vs. Unintentional

      • 1. If intentional (not an error): documented or not

      • 2. If unintentional: medication error

    • ii. Location: Admission orders vs. Discharge orders

    • iii. Type:

      • 1. Omission (not written for at all)

      • 2. Dose (per administration, e.g., 100 mg bid vs. 200 mg bid)

      • 3. Frequency (e.g., 100 mg bid vs. 100 mg tid)

        • a. Note that 100 mg bid vs. 200 mg qd would be a discrepancy in dose and frequency even though the total daily dose is the same.

      • 4. Route

      • 5. Substitution (i.e., with a medication in the same class)

      • 6. Additional medication (not taken at home, but ordered in the hospital)

    • iv. Reason:

      • 1. History error: this means the admitting physician made an error in taking the medication history, but then faithfully perpetuated this error when writing orders in the hospital.

      • 2. Reconciliation error: this means the medication history taken by the physician was correct, but the error occurred when writing the orders (this occurs at discharge much more often than at admission).

      • 3. Theoretically, both (1) and (2) could occur simultaneously.

• II. Potential for harm

  • a Definition: in your opinion, what is your confidence that the unintentional medication discrepancy described above has the potential to cause at least significant patient harm if the order is not corrected? Assume a reasonable patient (e.g., if an OTC prn medication is not prescribed, assume the patient can get access to it and resume it; but if a prescription medication is not prescribed, assume the patient does not have access to it).

  • b Scale

    • i. Little or no confidence (e.g., omission of multivitamin)

    • ii. Slight to modest confidence (e.g., colace 200 mg qam instead of 100 mg bid)

    • iii. Less than 50–50 but close call (e.g., omission of prn fleets enema at discharge)

    • iv. More than 50–50 but close call (e.g., omission of flovent bid at discharge)

    • v. Strong confidence (e.g., omission of prn haldol in nursing home patient)

    • vi. Virtually certain confidence (e.g., valium 10 mg instead of 1 mg prn insomnia)

• III. Potential Severity

  • a. Definition: this is the degree of patient harm that could be caused by the above unintentional medication discrepancy.

    • i. Significant: an error that can cause patient symptoms that, while harmful to the patient, pose little or no threat to the patient’s life function.

    • ii. Serious: an error than can cause signs/symptoms that are associated with a serious level of risk that is not high enough to be life-threatening. In addition, a potential ADE is serious if it can cause persistent alteration of daily function.

    • iii. Life-threatening: an error that can cause signs/symptoms that if not treated would put the patient at risk of death.

Examples of Potential ADE Severity Categories

(Assuming the discrepancy is unintentional)

LIFE THREATENING

• Incorrect dose of anti-rejection medication is prescribed in patient with kidney transplant

• Omission of amiodarone at discharge when given for prevention of VT

• Patient with a prior penicillin anaphylaxis reaction and ordered penicillin at admission

• Incorrect APAP dose prescribed at discharge with a total daily dose >15 grams

• Omission of warfarin at admission in patient with St. Jude’s mitral valve replacement

SERIOUS

• Patients’ correct dose is 2 mg diazepam, MD writes for 10 mg on admission

• Patient with CHF flare discharged on 1/4 preadmission dose of lasix

• Omission of beta-blocker at discharge in patient with CAD

• Warfarin 5 mg QD prescribed at discharge instead of 3 mg QD (prescribed for atrial fibrillation)

• Indomethacin for gout prescribed at discharge to patient concurrently taking Ibuprofen

• Two concurrent APAP prescriptions at discharge with a total daily dose of >10 grams but ≤15 grams

• Omission of lactulose bid in patient with history of hepatic encephalopathy

SIGNIFICANT

• Omission of diazepam prn insomnia at discharge

• Change from dulcolax prn to dulcolax bid standing

• Omission of lisinopril in patient without CAD, CHF, or valve disease

• Two concurrent APAP prescriptions with a total daily dose >4 grams but ≤10 grams

• Omission of ultram prn headaches

Additional Examples of Potential ADEs and their severity

• 1. Errors that may lead to hypotension or over-treatment of hypertension are considered to be serious potential ADEs.

• 2. Errors that may lead to under-treatment of hypertension, angina, or ischemia are considered to be significant potential ADEs.

• 3. Errors that may lead to significant over-anticoagulation or under-coagulation are considered to be serious potential ADEs.

• 4. Errors that lead to under-treatment of asthma are considered to be significant potential ADEs.

• 5. Errors that lead to under-treatment with antibiotics:

  • a. If IV antibiotics were originally prescribed, consider the errors to be serious potential ADEs.

  • b. If oral antibiotics were originally prescribed, consider the errors to be significant potential ADEs.

• 6. Errors that lead to over-treatment with antibiotics:

  • a. If either IV or oral antibiotics were prescribed, consider the errors to be significant potential ADEs, unless the antibiotic is directly toxic to end organs in a highly dose-sensitive fashion (e.g., gentamicin), in which case, the severity will be higher (usually serious).