Predictors of warfarin-associated adverse events in hospitalized patients: Opportunities to prevent patient harm

Temporal trends in postoperative and ventilator-associated pneumonia in the United States

OBJECTIVE

To determine change in rates of postoperative pneumonia and ventilator-associated pneumonia among patients hospitalized in the United States during 2009-2019.

DESIGN

Retrospective cohort study.

PATIENTS

Patients hospitalized for major surgical procedures, acute myocardial infarction, heart failure, and pneumonia.

METHODS

We conducted a retrospective review of data from the Medicare Patient Safety Monitoring System, a chart-abstraction-derived database including 21 adverse-event measures among patients hospitalized in the United States. Changes in observed and risk-adjusted rates of postoperative pneumonia and ventilator-associated pneumonia were derived.

RESULTS

Among 58,618 patients undergoing major surgical procedures between 2009 and 2019, the observed rate of postoperative pneumonia from 2009-2011 was 1.9% and decreased to 1.3% during 2017-2019. The adjusted annual risk each year, compared to the prior year, was 0.94 (95% CI, 0.92-0.96). Among 4,007 patients hospitalized for any of these 4 conditions at risk for ventilator-associated pneumonia during 2009-2019, we did not detect a significant change in observed or adjusted rates. Observed rates clustered around 10%, and adjusted annual risk compared to the prior year was 0.99 (95% CI, 0.95-1.02).

CONCLUSIONS

During 2009-2019, the rate of postoperative pneumonia decreased statistically and clinically significantly in among patients hospitalized for major surgical procedures in the United States, but rates of ventilator-associated pneumonia among patients hospitalized for major surgical procedures, acute myocardial infarction, heart failure, and pneumonia did not change.

Time Trends in Patient Characteristics and In-Hospital Adverse Events for Primary Total Knee Arthroplasty in the United States: 2010-2017

Background

Perioperative care for total knee arthroplasty (TKA) has improved over time. We present an analysis of inpatient safety after TKA.

Methods

14,057 primary TKAs captured by the Medicare Patient Safety Monitoring System between 2010 and 2017 were retrospectively reviewed. We calculated changes in demographics, comorbidities, and adverse events (AEs) over time. Risk factors for AEs were also assessed.

Results

Between 2010 and 2017, there was an increased prevalence of obesity (35.1% to 57.6%), tobacco smoking (12.5% to 17.8%), and renal disease (5.2% to 8.9%). There were reductions in coronary artery disease (17.3% to 13.4%) and chronic warfarin use (6.7% to 3.1%). Inpatient AEs decreased from 4.9% to 2.5%, (P < .01), primarily driven by reductions in anticoagulant-associated AEs, including major bleeding and hematomas (from 2.8% to 1.0%, P < .001), catheter-associated urinary tract infections (1.1% to 0.2%, P < .001), pressure ulcers (0.8% to 0.2%, P < .001), and venous thromboembolism (0.3% to 0.1%, P = .04). The adjusted annual decline in the risk of developing any in-hospital AE was 14% (95% confidence interval [CI] 10%-17%). Factors associated with developing an AE were advanced age (odds ratio [OR] = 1.01, 95% CI 1.00-1.01), male sex (OR = 1.21, 95% CI 1.02-1.44), coronary artery disease (OR = 1.35, 95% CI 1.07-1.70), heart failure (OR = 1.70, 95% CI 1.20-2.41), and renal disease (OR = 1.71, 95% CI 1.23-2.37).

Conclusions

Despite increasing prevalence of obesity, tobacco smoking, and renal disease, inpatient AEs after primary TKA have decreased over the past several years. This improvement is despite the increasing complexity of the inpatient TKA population over time.

Nursing self-efficacy for oral anticoagulant therapy management: Development and initial validation of a theory-grounded scale

AIM

This study aimed to develop and validate a nursing self-efficacy scale for OAC management (SE-OAM).

BACKGROUND

Oral anticoagulant therapy (OAC) requires specific nursing competencies. Given that self-efficacy acts as a proxy assessment of nursing competence, its measurement is pivotal for addressing educational programs to enhance nursing competence in managing OAC. Thus far, the measurement of self-efficacy in OAC is undermined by the unavailability of valid and reliable tools.

METHODS

A multi-method and multi-phase design was adopted: Phase one was a methodological study encompassing developmental tasks for generating items. Phase two comprised the validation process for determining the content validity, construct and concurrent validity, and internal consistency through two cross-sectional data collections.

RESULTS

In total, 190 nurses were enrolled for determining the psychometric structure of the SE-OAM through an exploratory approach, and 345 nurses were subsequently enrolled to corroborate its most plausible factor structure derived from the exploratory analysis. The SE-OAM showed evidence of face and content validity, adequate construct, concurrent validity, good internal consistency, and stability. The final version of the scale encompassed 21 items kept by five domains: clinical management, care management, education, clinical monitoring, and care monitoring.

CONCLUSIONS

The SE-OAM showed evidence of initial validity and reliability, fulfilling a current gap in the availability of tools for measuring nursing self-efficacy in managing OAC. SE-OAM could be strategic for performing research to improve the quality of OAC management by enhancing nursing self-efficacy.

Association Between Medicare Expenditures and Adverse Events for Patients With Acute Myocardial Infarction, Heart Failure, or Pneumonia in the United States

IMPORTANCE

Studies have shown that adverse events are associated with increasing inpatient care expenditures, but contemporary data on the association between expenditures and adverse events beyond inpatient care are limited.

OBJECTIVE

To evaluate whether hospital-specific adverse event rates are associated with hospital-specific risk-standardized 30-day episode-of-care Medicare expenditures for fee-for-service patients discharged with acute myocardial infarction (AMI), heart failure (HF), or pneumonia.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study used the 2011 to 2016 hospital-specific risk-standardized 30-day episode-of-care expenditure data from the Centers for Medicare & Medicaid Services and medical record-abstracted in-hospital adverse event data from the Medicare Patient Safety Monitoring System. The setting was acute care hospitals treating at least 25 Medicare fee-for-service patients for AMI, HF, or pneumonia in the United States. Participants were Medicare fee-for-service patients 65 years or older hospitalized for AMI, HF, or pneumonia included in the Medicare Patient Safety Monitoring System in 2011 to 2016. The dates of analysis were July 16, 2017, to May 21, 2018.

MAIN OUTCOMES AND MEASURES

Hospitals' risk-standardized 30-day episode-of-care expenditures and the rate of occurrence of adverse events for which patients were at risk.

RESULTS

The final study sample from 2194 unique hospitals included 44 807 patients (26.1% AMI, 35.6% HF, and 38.3% pneumonia) with a mean (SD) age of 79.4 (8.6) years, and 52.0% were women. The patients represented 84 766 exposures for AMI, 96 917 exposures for HF, and 109 641 exposures for pneumonia. Patient characteristics varied by condition but not by expenditure category. The mean (SD) risk-standardized expenditures were $22 985 ($1579) for AMI, $16 020 ($1416) for HF, and $16 355 ($1995) for pneumonia per hospitalization. The mean risk-standardized rates of occurrence of adverse events for which patients were at risk were 3.5% (95% CI, 3.4%-3.6%) for AMI, 2.5% (95% CI, 2.5%-2.5%) for HF, and 3.0% (95% CI, 2.9%-3.0%) for pneumonia. An increase by 1 percentage point in the rate of occurrence of adverse events was associated with an increase in risk-standardized expenditures of $103 (95% CI, $57-$150) for AMI, $100 (95% CI, $29-$172) for HF, and $152 (95% CI, $73-$232) for pneumonia per discharge.

CONCLUSIONS AND RELEVANCE

Hospitals with high adverse event rates were more likely to have high 30-day episode-of-care Medicare expenditures for patients discharged with AMI, HF, or pneumonia.

Standardized warfarin monitoring decreases adverse drug reactions

Background

While warfarin is the most commonly prescribed medication to prevent thromboembolic disorders, the risk of adverse drug reactions (ADR) poses a serious concern. This prospective study evaluated how primary care providers (PCP) and cardiologists at our Institution managed patients treated with warfarin with the goal of decreasing the number of warfarin ADRs.

Methods

A multidisciplinary anticoagulation task force was established at our Institution in 2014 to standardize warfarin monitoring and management. Between 2013 and 2017, we analyzed patients who were prescribed warfarin by their PCP or cardiologist upon hospital discharge and in the ambulatory setting to determine the international normalized ratio (INR) within 5, 10, and 30 days after discharge, time in therapeutic range (TTR), number of severe warfarin ADRs, and total and average cost reduction of all severe warfarin ADRs to determine whether there was an organizational cost savings following the implementation of standardized warfarin care.

Results

The warfarin ADR rate significantly decreased over the 5-year period, from 3.8 to 0.98% (p < 0.0001). The proportion of warfarin prescriptions out of all anticoagulants significantly decreased, from 72.2 to 42.1% (p < 0.001). The proportion of individuals who received an INR at 5, 10, and 30 days after hospital discharge compared to the total number of patients prescribed warfarin significantly increased (p < 0.001). The total cost of severe warfarin ADRs decreased by 57.6% between 2013 and 2017.

Conclusions

This study serves as a model to reduce the number of severe warfarin ADRs by the following tactics: (1) educating PCPs and cardiologists about evidence-based guidelines for warfarin management, (2) increasing the use of our Institution’s electronic warfarin module, and (3) enhancing patient compliance with obtaining INR.

Warfarin Quality Metrics for Hospitalized Older Adults

Background  Warfarin's adverse drug events are dangerous, common, and costly. While outpatient warfarin management tools exist, there is a dearth of guidance for inpatients.

Objectives  We sought to describe a health system's chronic warfarin quality metrics in older inpatients, defined by international normalized ratio (INR) control, explore associations between INR overshoots and clinical outcomes, and identify factors associated with overshoots.

Patients/Methods  Data on patients 65 years and older who were prescribed chronic warfarin and admitted during January 1, 2014, to June 30, 2016, were extracted through retrospective chart review. We defined overshoots as INRs 5 or greater after 48 hours of hospitalization. Logistic regression modeling was used to determine risks for overshoots and multivariate analysis for overshoots' association with length of stay (LOS), bleeding, and mortality.

Results  Of the 12,107 older inpatients on chronic warfarin, most were 75 years or older (75.7%), female (51.2%), and white (70.0%). While 1,333 (11.0%) of patients had overshoots during the admission, 449 (33.7%) of these reached overshoots after 48 hours. When stratified by overshoots versus no overshoots, LOS more than doubled (15.6 vs. 6.8 days) and the bleed rate was significantly higher (27.4 vs. 8.3%) in the overshoot group. While overall mortality was small (0.4%), the overshoot group's mortality was significantly higher (3.12 vs. 0.28%). Black race and weight were protective against overshoots; history of heart failure and antibiotic/amiodarone exposure were predictive of overshoots.

Conclusion  This is the largest study examining warfarin quality metrics for hospitalized adults, specifically older inpatients. Our model may serve as the basis for identifying high-risk warfarin patients to target interventions to reduce adverse drug events.

Quality metrics of warfarin initiation in hospitalized older adults

Achieving therapeutic international normalized ratio (INRs) in warfarin naïve older adults can be complicated due to sensitivity factors. While multiple tools exist for warfarin initiation in the outpatient setting, there is a dearth of guidance for inpatient initiation. This study aims to: (1) describe a large health system's initiation warfarin quality metrics in older inpatients, defined by INR overshoots greater than or equal to 5.0; (2) identify intrinsic and extrinsic patient factors associated with overshoots; and (3) explore the association between inpatient overshoots and clinical outcomes. Data on inpatients ≥ 65 years initiated on warfarin 1/1/2014-6/30/2016 were extracted through retrospective chart review. The primary outcome was prevalence of overshoots (INR ≥ 5). Logistic regression modeling determined the risk factors for overshoots. Multivariate analysis was employed to associate overshoots with length of stay (LOS), bleeding, and mortality. Additional analysis of the impact of patient weight (kg) on overshoots was achieved through chi square analysis. Of 4556 inpatients initiated on warfarin, 8% experienced overshoots. Non-black race, peripheral vascular disease, chronic obstructive pulmonary disease (COPD), mild liver disease, low weight, and no statin use were found to be predictive of overshoots. Compared to the group without overshoots, the group with overshoots experienced a significantly increased LOS (13 days vs. 8 days, < 0.001), higher bleed rate (30.1% vs. 6.5%, adjusted OR 6.2, p < 0.001), and higher mortality rate (13.8% vs. 3.4%, adjusted OR 4.4, p < 0.001). Inpatient warfarin initiation was associated with frequent overshoots and poor outcomes. Future studies should focus on strategies to improve hospital warfarin initiation safety.

Improving inpatient warfarin therapy safety using a pharmacist-managed protocol

Introduction

Safe management of warfarin in the inpatient setting can be challenging. At the Mayo Clinic hospitals in Rochester, Minnesota, we set out to improve the safety of warfarin management among surgical and non-surgical inpatients.

Methods

A multidisciplinary team designed a pharmacist-managed warfarin protocol (PMWP) which designated warfarin dosing to inpatient pharmacists with guidance from computerised dosing algorithms. Ordering this protocol was ultimately designed as an ‘opt out’ practice. The primary improvement measure was frequency of international normalised ratio (INR) greater than 5; secondary measures included adoption rate of the protocol, a counterbalance INR metric (INR <1.7 three days after first inpatient warfarin dose), and complication rates, including bleeding and thrombosis events. An interrupted time series analysis was conducted to compare outcomes.

Results

Among over 50 000 inpatient warfarin recipients, the PMWP was adopted for the majority of both surgical and non-surgical inpatients during the study period (1 January 2005 to 31 December 2011). The primary improvement measure decreased from 5.6% to 3.4% for medical patients and from 5.2% to 2.4% for surgical patients during the preimplementation and postimplementation periods, respectively. The INR counterbalance measure did not change. Postoperative bleeding decreased from 13.5% to 11.1% among surgical patients, but bleeding was unchanged among medical patients.

Conclusion

Our PMWP led to achievement of improved INR control for inpatient warfarin recipients and to less near-term bleeding among higher risk, surgical patients.