An estimated 158 000 surgical site infections (SSIs) occur in the Unites States annually, at a cost of $3.45 billion to $10.07 billion.1,2 Investigations have demonstrated the efficacy of infection prevention bundles in reducing SSIs across multiple surgical specialties.3,4 Neurosurgical SSIs incur the highest costs, and spine surgeries account for more than 1.01 million procedures annually, presenting an opportunity for reducing health care–related harm and expenditures.5 We hypothesized that implementation of an infection prevention bundle would be associated with a reduction in SSIs and disease-specific costs.
The Cleveland Clinic Institutional Review Board approved this pragmatic, quasi-experimental cohort study, and it was conducted between March 2012 and December 2013. Informed consent was not required because this was a quality improvement initiative with minimal risk. A waiver of informed consent was obtained from the institutional review board. In January 2013, an infection prevention bundle was introduced at a single tertiary-care center. Patients undergoing discectomy, decompression, augmentation, or fusion of the spine were included. The analysis of the data was conducted in January 2015.
The bundle included 9 evidence-based components: (1) screening for Staphylococcus aureus nasal colonization and decolonization with mupirocin, (2) self-preparation bath with chlorhexidine gluconate, (3) self-preparation with chlorhexidine gluconate wipes,6 (4) storage optimization of operating room supplies, (5) preoperative antibiotic administration algorithm, (6) staff training on betadine scrub and paint, (7) intrawound vancomycin in instrumented cases, (8) postoperative early patient mobilization, and (9) wound checks at 2 and 6 weeks postoperatively. Infection preventionists prospectively monitored SSIs using National Healthcare Safety Network definitions.
The surgical episode of care was defined in 3 periods: 30 days prior to admission, the index admission, and discharge to 365 days after admission. Institutional resource-level cost data were extracted, including inpatient and outpatient encounters related to spine care. Infection-specific costs were defined as all episode-of-care costs incurred after the diagnosis of an SSI. To present costs from the payer’s perspective, costs were normalized to national Medicare reimbursement and presented in 2014 US dollars.
The primary and secondary outcomes were the incidence of SSI and total episode-of-care costs, respectively. Logistic and log-transform linear regression were used to control for covariates associated (P < .05) with outcomes. A Bonferroni correction was used, with P < .03 considered statistically significant.
Characteristics of the 1770 included patients are presented in Table 1. Nasal swab amplification demonstrated that 39 patients (5%) in the intervention cohort were carriers of methicillin-resistant S aureus while 101 (13%) were carriers of methicillin-susceptible S aureus. Forty infections were observed in the preintervention cohort, while 16 were observed in the intervention cohort (4.12% vs 2.00%; risk ratio, 0.48; 95% CI, 0.27-0.86; P = .01). The number needed to treat to prevent 1 infection was 47. Following multivariate logistic regression (Table 2), the intervention remained associated with a decrease in SSIs (odds ratio, 0.49; 95% CI, 0.26-0.87; P = .02).
Unadjusted episode-of-care costs were lower in the intervention cohort ($32 520 vs $28 462, P = .02). Per infection, the median infection-specific cost was $25 962 (interquartile range, $7752-$52 972). Surgical site infections added $1693 to each patient’s episode of care in the preintervention cohort and $827 in the intervention cohort. Following multivariate linear regression, the intervention was associated with a savings of $866 per patient.
Implementation of an infection prevention bundle was associated with a 50% reduction in SSIs and an $866 per capita reduction in the surgical episode of care cost. Establishment of causality is challenging in a nonrandomized study; however, pragmatic interventions are associated with improved quality within the normal operations of a health system and may offer improved care to a greater number of patients.
Given the national volume of spine surgery, an $866 cost reduction translates into an approximate $880 million reduction nationally, although these savings are extrapolated from a single institution. Similar savings may not be achieved at all institutions following bundle implementation. These data suggest that appropriate implementation of an infection prevention bundle can reduce unnecessary harm and expenditures, translating to a clear increase in value.
Corresponding Author: Ajit A. Krishnaney, MD, Center for Spine Health, Department of Neurological Surgery, Neurological Institute, Cleveland Clinic Foundation, 9500 Euclid Ave, Cleveland, OH 44195 (KRISHNA@ccf.org).
Date of Revision: April 04, 2016.
Published Online: July 20, 2016. doi:10.1001/jamasurg.2016.1794.
Author Contributions: Mr Featherall and Mr Miller had full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.
Study concept and design: Featherall, Khalaf, Krishnaney.
Acquisition, analysis, or interpretation of data: All authors.
Drafting of the manuscript: Featherall, Miller, Khalaf, Krishnaney.
Critical revision of the manuscript for important intellectual content: All authors.
Statistical analysis: Featherall, Miller.
Administrative, technical, or material support: Featherall, Khalaf.
Study supervision: Krishnaney.
Conflict of Interest Disclosures: None reported.
Additional Contributions: Infection data extraction and stewardship: Cynthia Fatica, RN CIC, Senior Director of Infection Prevention. Financial data extraction and stewardship: Gregory Stronsick and Charles Sweeney, financial managers, Cleveland Clinic Foundation. No compensation was received from a funding sponsor for these contributions.
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