Patients with comorbidities, older age, and public insurance at highest risk for readmission

Nearly 20% of hospital readmissions following major surgical procedures may be preventable, suggesting that improved access to outpatient care — particularly among high-risk patients — may reduce postoperative readmissions and lead to huge reductions in health care spending, researchers found.

Surgical patients with comorbidities including congestive heart failure (CHF), chronic obstructive pulmonary disease, hypertension, end-stage kidney disease, and diabetes typically suffer from higher rates of postsurgical complications requiring hospital readmission, Craig S. Brown, MD, MSc, of the Department of Surgery at the University of Michigan in Ann Arbor, and colleagues explained in JAMA Network Open. However, “the underlying mechanisms associated with readmissions after surgery are complex and poorly understood,” they noted, adding that it is difficult to determine the rate of potentially preventable readmissions (PPR) that could be averted with access to outpatient care.

Using the ambulatory care sensitive conditions (ASCS) framework adopted by the Agency for Healthcare Research Quality (AHRQ), Brown and colleagues conducted an analysis to assess the degree to which readmissions are preventable following certain major surgeries.

“In this study of readmissions from the [National Readmissions Database] NRD, we found that nearly 1 in 5 readmissions after these selected major surgical procedures were potentially preventable, with an estimated cost to hospitals of nearly $300 million annually. We also found that patients who were readmitted for potentially preventable reasons had worse underlying health, as evidenced by our findings that these patients were older and more likely to have a variety of comorbidities, most notably those that are directly associated with ACSC such as [congestive heart failure] CHF, chronic obstructive pulmonary disease, chronic kidney disease, or diabetes. Finally, the likelihood of PPRs was closely associated with both income and health insurance coverage.”

“The study by Brown and colleagues helps to shine the light on very rational starting points for all of us to pick up the challenge of pursuing efficiency and eliminating waste, on behalf of current patients and on behalf of those who today and in future days will bear the costs of health care in the United States,” Bruce L. Hall, MD, PhD, MBA, and Sheyda Namazie-Kummer, MD, MBA, of the Center for Clinical Excellence at BJC Healthcare in St. Louis, Missouri, wrote in an invited commentary. “As we highlight the need for better transition and posthospital resources, we will empower examinations of the inequity of those resources currently. It is our moral obligation to pick up these challenges and run.”

However, Hall and Namazie-Kummer also noted that questions remain.

“Brown et al state that comorbidities associated with increased odds of PPR included congestive heart failure, dementia, chronic obstructive pulmonary disease, rheumatoid disease, diabetes, chronic kidney disease, liver disease, metastatic cancer, and AIDS,” they wrote. “Do these truly increase the risk of preventable readmissions as an early target, or are these only associated with readmission in general? Similarly, the results in the study by Brown et al indicate that public insurance type and low income were associated with overall readmissions and PPR, not just PPR…But all readmission types are likely to fall on a continuous spectrum of preventability, which could look different depending on procedure, patient, and environmental factors. Rather than negating the value of establishing readmissions that are most modifiable, this reality encourages and rewards our search for the most preventable readmissions…”

For their retrospective analysis, Brown and colleagues pulled data from the 2017 Healthcare Cost and Utilization Project (HCUP) NRD in order to assess all adult inpatient hospitalizations for coronary artery bypass grafting, open abdominal aortic aneurysm repair, lower extremity peripheral arterial bypass, laparoscopic or open colon resection, video-assisted or open thoracoscopic pulmonary lobectomy, total hip arthroplasty, or total knee arthroplasty.

The study’s primary outcome was readmission within 90 days following hospital discharge after any of the aforementioned procedures that were considered potentially preventable — a primary diagnosis code for any of the ASCSs as defined by the AHRQ, plus three specific categories: superficial surgical site infection, acute kidney injury, and aspiration pneumonia or pneumonitis. They also collected demographic characteristics such as age, sex, insurance, surgical procedure, elective or emergency procedure, and comorbidities. Hospital cost estimates were generated using the charge data available for each admission as well as hospital-level cost to charge ratios provided by HCUP.

“A total weighted sample of 1,937,354 patients (1,048,046 women [54.1%]; mean age, 66.1 years [95% CI, 66.0-66.3 years]) underwent surgical procedures; 164,755 (8.5%) experienced a readmission within 90 days,” Brown and colleagues reported. “Potentially preventable readmissions accounted for 29,321 (17.8%) of all 90-day readmissions, for an estimated total cost to the U.S. health care system of approximately $296 million. The most common reasons for PPRs were congestive heart failure exacerbation (34.6%), pneumonia (12.0%), and acute kidney injury (22.5%). In a multivariable model of adults aged 18 to 64 years, patients with public health insurance (Medicare or Medicaid) had more than twice the odds of PPR compared with those with private insurance (adjusted odds ratio, 2.09; 95% CI, 1.94-2.25). Among patients aged 65 years or older, patients with private insured had 18% lower odds of PPR compared with patients with Medicare as the primary payer (adjusted odds ratio, 0.82; 95% CI, 0.74-0.90).”

Brown and colleagues added that “Each additional decade increase in age was associated with a 20% increase in odds of PPR (adjusted odds ratio [aOR], 1.20; 95% CI, 1.17-1.22), and female sex was associated with a 6% increase in odds of PPR (aOR, 1.06; 95% CI, 1.02-1.10). Furthermore, patients treated at metropolitan teaching hospitals had 8% lower odds of PPR compared with patients in a metropolitan nonteaching hospital (aOR, 0.92; 95% CI, 0.85-0.99)…Emergency surgery was associated with a more than 8-fold increase in the odds of PPR (aOR, 8.24; 95% CI, 7.63-8.92), and several of the comorbidities investigated were associated with increased odds of PPR, including CHF (aOR, 2.99; 95% CI, 2.85-3.13), dementia (aOR, 1.19; 95% CI, 1.11-1.28), chronic obstructive pulmonary disease (aOR, 1.51; 95% CI, 1.45-1.57), rheumatoid disease (aOR, 1.15; 95% CI, 1.04-1.27), diabetes (aOR, 1.54; 95% CI, 1.46-1.62), chronic kidney disease (aOR, 1.77; 95% CI, 1.68-1.85), liver disease (aOR, 1.31; 95% CI, 1.02-1.69), metastatic cancer (aOR, 1.15; 95% CI, 1.03-1.28), and AIDS (aOR, 1.87; 95% CI, 1.25-2.79).”

The study authors noted that “the difficulty in disentangling the relative responsibility of hospital and patient factors in optimizing the transition from inpatient to outpatient care in the postoperative period, and its applicability to complication-associated readmissions, has traditionally limited enthusiasm for use of readmissions as a quality indicator for surgical patients.” However, their results suggest that a large proportion of readmissions in the post-op setting may be associated with factors linked to transitions from inpatient to outpatient care rather than the inherent risks of the procedure or it’s complications.

“Furthermore, our finding of significant variation in PPR rates across a variety of socioeconomic factors and based on primary payer status, as proxies for access to care, suggests that improved access to ambulatory care may result in decreased rates of readmissions for these potentially preventable causes and a significant savings in cost and burden to the health care system as a whole,” they wrote.

Study limitations include limited clinical information in the NRD in regard to the operative procedures, hospitalizations, or readmissions, and unmeasured bias in the estimates for the covariates investigated.

  1. Nearly 20% of hospital readmissions following major surgical procedures were possibly preventable with improved access to outpatient care.

  2. The most common reasons for PPRs were congestive heart failure exacerbation, pneumonia, and acute kidney injury, and patients who were older, female, or on public health insurance were at the highest risk for readmission.

John McKenna, Associate Editor, BreakingMED™

Brown receives funding from the Ruth L. Kirschstein Postdoctoral Research Fellowship Award administered by the National Institute on Drug Abuse (grant F32-DA050416).

Coauthor Tsai reported serving on the scientific advisory board for Seamless Mobile Health and receiving personal fees from Sigilon Therapeutics and Medtronic outside the submitted work. Coauthor Dimick reported receiving personal fees from ArborMetrix Inc. outside the submitted work.

Hall reported serving as the consulting director of the American College of Surgeons National Surgical Quality Improvement Program.

Cat ID: 159

Topic ID: 97,159,728,791,730,3,914,127,192,925,159,492