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Table 1 Incidence of hospital-acquired conditions (HACs) by frailty severity
Source: Passias et al. “Preoperative Optimization of Modifiable Frailty Factors Reduces Risk of Hospital-acquired Conditions in Elective Surgical Spine Patients.”


Published 9/3/2021
Rebecca Araujo

Diabetes, Hypertension in Spine Surgery Patients May Increase Risk of Hospital-acquired Conditions

In a study of patients undergoing elective spine surgery, frailty was associated with prevalence of certain hospital-acquired conditions (HACs). Hypertension and diabetes were two modifiable factors associated with increased risk of frailty. The findings were presented on Tuesday, by Peter G. Passias, MD, FAAOS, of NYU Langone Health.

Established by way of the Affordable Care Act, HACs are defined as “reasonably preventable complications” and are non-reimbursable. “As surgeons continue operating on populations who are increasingly higher risk, as in cases of frail spine patients, preoperative evaluation should be considered for potential modifiable risk factors to mitigate and reduce the incidence of HACs,” study coauthor Oscar Krol, MD, told AAOS Now Daily Edition. Dr. Krol is a research fellow at NYU Langone Medical Center Spine Research Institute.

The investigators evaluated the effects of modifiable patient factors on HAC risk in 196,523 patients who underwent spine surgery between 2005 and 2016. Patients were enrolled in the American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) database, and the authors used the ACS-NSQIP five-factor frailty index to stratify patients’ risk for complications. The modified frailty score (mFI-5) is rated from 0 to 1 (no frailty [NF], <0.3; mild frailty [mf], 0.3–0.5; severe frailty [sf],>0.5).

“The frailty indices have previously been shown to be efficacious at predicting operative complications,” Dr. Krol explained.

The average age of the study population was 57 years, and the cohort was 48.0 percent female. The breakdown of frailty ratings across the cohort was:

  • NF: 83.6 percent
  • MF: 15.1 percent
  • SF: 1.3 percent

The overall rate of HACs was 2.9 percent (n = 5,720). The most common complications were surgical site infection (SSI, 1.3 percent) and urinary tract infection (UTI, 1.1 percent).

Incidence of HACs according to frailty severity were 2.64 percent in the NF group, 4.17 percent in the MF group, and 5.93 percent in the SF group (all P <0.001). see the table for a further breakdown of hac incidence by frailty severity.>

Stepwise regression found that diabetes mellitus and hypertension were the most significant predictors of higher baseline frailty. Thus, the “optimal” modifiable frailty factors were defined as no history of diabetes or hypertension.

“Diabetes has been a well-documented contributor to increased morbidity and mortality following surgery, and, similarly, patients who suffer from hypertension have also been demonstrated to have increased rates of postoperative complication. Our findings were therefore consistent with literature,” noted Dr. Krol.

When the researchers compared “optimized” patients to “nonoptimized” patients, they found a significantly lower overall incidence of HACs among optimized patients (2.18 percent versus 3.56 percent; P <0.001). optimized patients also had lower incidence of ssi (2.03 percent versus 2.5 percent;>P <0.001), uti (0.65 percent versus 1.4 percent,> P <0.001), and deep vein thrombosis (0.56 percent versus 0.84 percent,>P <0.001) compared to nonoptimized patients.>

“Stepwise linear regression models determined that hypertension and diabetes account for 89.7 percent of variance in baseline mFI-5 score,” the authors wrote in their summary. “Patients with these optimal controllable factors had reduced incidence of all HACs.”

Dr. Krol added, “With these modifiable factors controlled, it may be possible to mitigate and reduce HACs, thereby improving patient outcomes as well as saving valuable healthcare resources. Further exploration of other modifiable risk factors may increasingly promote safer, more effective, and more cost-effective surgery.”

The authors noted that the study is limited by its retrospective nature, as well as the use of the ACS-NSQIP database, which relies on accurate coding. “We feel that the use of a large database, even with its limitations, is the most effective way to evaluate specific components of the frailty index and the association with HACs,” said Dr. Krol.

This study focused on isolated HACs such as SSI, UTI, and venous thromboembolism; however, “there may be many more complications that are impacted by additional disease pathologies other than those identified in our analysis,” Dr. Krol noted.

“A more limited evaluation of the most serious complications is the most effective means of drawing concise, meaningful, and impactful results,” he added.

Drs. Passias and Krol’s coauthors of “Preoperative Optimization of Modifiable Frailty Factors Reduces Risk of Hospital-acquired Conditions in Elective Surgical Spine Patients” are Katherine E. Pierce, MD; Sara Naessig, MD; Waleed Ahmad, MD; Lara Passfall, MD; Bhaveen H. Kapadia, MD; Shaleen Vira, MD; and Bassel Diebo, MD.

Rebecca Araujo is the associate editor of AAOS Now. She can be reached at raraujo@aaos.org.