Recent Increase in the Rate of Spinal Infections May be Related to Growing Substance-use Disorder in the State of Washington: Wide Population-based Analysis of the Comprehensive Hospital Abstract Reporting System (CHARS) Database

Spinal infection: Assessing comorbidities and costs to inform patient management and resource use strategies

Background

Spinal Infection (SI) is associated with various comorbidities. The interaction of these comorbidities and their impact on costs and complexity of care has not been fully assessed.

Methods

This is a retrospective cohort study of SI patients in an urban hospital system to characterize comorbidities and outcomes in adult patients with SI. Adult patients in our hospital system who were hospitalized with an initial diagnosis of SI between July 1, 2017 and June 30, 2019 were included. Outcomes measures included length of stay (LOS) of the index hospitalization for SI, charges and payments for the index hospitalization, and hospital readmissions within one year after discharge from the index hospitalization. Data was obtained by querying our Electronic Data Warehouse (EDW) using ICD-10-CM and CPT procedure codes. Spearman's correlation was used to summarize the relationships between LOS, charges, and payments. Multivariable linear regression was used to evaluate associations of demographics, comorbidities, and other factors with LOS. Multivariable Cox regression was used to evaluate associations of demographics, comorbidities, and other factors with hospital readmissions.

Results

403 patients with a first diagnosis of SI were identified. The average number of comorbidities per patient was 1.3. 294 (73%) had at least 1 medical comorbidity, and 54 (13%) had 3 or more comorbidities. The most common medical comorbidities were diabetes mellitus (26%), intravenous drug use (IVDU, 26%), and malnutrition (20%). 112 patients (28%) had a surgical site infection (SSI). DM (p<.001) and SSI (p=.016) were more common among older patients while IVDU was more common among younger patients (p<.001). Median LOS was 12 days. A larger number of medical comorbidities was associated with a longer LOS (p<.001) while the presence of a SSI was associated with a shorter LOS (p=.007) after multivariable adjustment. LOS was positively correlated with both charges (r=0.83) and payments (r=0.61). Among 389 patients discharged after the index hospitalization, 36% had a readmission within 1 year. The rate of readmission was twice as high for patients with three or more comorbidities than patients with zero comorbidities (hazard ratio: 1.95, p=.017).

Conclusions

Patients with SI often have multiple comorbidities, and the specific type of comorbidity is associated with the patient's age. The presence of multiple comorbidities correlates with initial LOS, cost of care, and readmission rate. Readmission in the first year post-discharge is high.

Are Dental Procedures Associated With Pyogenic Vertebral Osteomyelitis?

BACKGROUND

Dental procedures can lead to bacteremia and have been considered a potential risk factor for pyogenic vertebral osteomyelitis (PVO). However, data on the association between dental procedures and PVO are limited.

QUESTIONS/PURPOSES

(1) After controlling for relevant confounding variables, are dental procedures associated with an increased risk of PVO? (2) Does antibiotic prophylaxis before dental procedures effectively decrease the risk of PVO?

METHODS

A case-crossover study was conducted to investigate the association between dental procedures and PVO using a Japanese claims database. The advantage of this study design is that confounding factors that do not vary over time are automatically adjusted for, because cases act as their own controls. From April 2014 to September 2021, the database included 8414 patients who were hospitalized for PVO. Of these, 50% (4182 of 8414) were excluded because they had not undergone any dental procedures before the index date, a further 0.1% (10 of 8414) were excluded because they were younger than 18 years at the index date, and a further 7% (623 of 8414) were excluded because they did not have at least 20 weeks of continuous enrollment before the index date, leaving 43% (3599 of 8414) eligible for analysis here. The mean age was 77 ± 11 years, and 55% (1985 of 3599) were men. Sixty-five percent (2356 of 3599) of patients had a diagnosis of diabetes mellitus, and 42% (1519 of 3599) of patients had a diagnosis of osteoporosis. We compared the frequency of dental procedures between a 4-week hazard period before the admission date for PVO and two control periods, 9 to 12 weeks and 17 to 20 weeks before the admission date for PVO, within individuals. We calculated odds ratios and 95% confidence intervals using conditional logistic regression analysis.

RESULTS

Comparing the hazard and matched control periods within individuals demonstrated that dental procedures were not associated with an increased risk of PVO (OR 0.81 [95% CI 0.72 to 0.92]; p < 0.001). Additional analysis stratified by antibiotic prophylaxis use showed that antibiotic prophylaxis was not associated with a lower OR of developing PVO after dental procedures (with antibiotic prophylaxis: OR 1.11 [95% CI 0.93 to 1.32]; p < 0.26, without antibiotic prophylaxis: OR 0.72 [95% CI 0.63 to 0.83]; p < 0.001). Our sensitivity analyses, in which the exposure assessment interval was extended from 4 to 8 or 12 weeks and exposure was stratified by whether the dental procedure was invasive, demonstrated results that were consistent with our main analysis.

CONCLUSION

Dental procedures were not associated with an increased risk of subsequent PVO in this case-crossover study. The effectiveness of antibiotic prophylaxis was not demonstrated in the additional analysis that categorized exposure according to the use of antibiotic prophylaxis. Our results suggest that the association between dental procedures and PVO may have been overestimated. Maintaining good oral hygiene may be important in preventing the development of PVO. The indications for antibiotic prophylaxis before dental procedures should be reconsidered in view of the potential risk of adverse drug reactions to antibiotic prophylaxis and the emergence of drug-resistant pathogens. Larger randomized controlled trials are needed to confirm these findings and assess the role of antibiotic prophylaxis.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Recurrence rate after posterior percutaneous screw fixation without anterior debridement for pyogenic spondylitis compared with conservative treatment: a propensity score-matched analysis

PURPOSE

Previous studies have shown that percutaneous pedicle screw (PPS) posterior fixation without anterior debridement for pyogenic spondylitis can improve patient quality of life compared with conservative treatment. However, data on the risk of recurrence after PPS posterior fixation compared with conservative treatment is lacking. The aim of this study was to compare the recurrence rate of pyogenic spondylitis after PPS posterior fixation without anterior debridement and conservative treatment.

METHODS

The study was conducted under a retrospective cohort design in patients hospitalized for pyogenic spondylitis between January 2016 and December 2020 at 10 affiliated institutions. We used propensity score matching to adjust for confounding factors, including patient demographics, radiographic findings, and isolated microorganisms. We estimated hazard ratios (HRs) and 95% confidence intervals (CIs) for recurrence of pyogenic spondylitis during the follow-up period in the matched cohort.

RESULTS

148 patients (41 in the PPS group and 107 in the conservative group) were included. After propensity score matching, 37 patients were retained in each group. PPS posterior fixation without anterior debridement was not associated with an increased risk of recurrence compared with conservative treatment with orthosis (HR, 0.80; 95% CI, 0.18-3.59; P = 0.77).

CONCLUSIONS

In this multi-center retrospective cohort study of adults hospitalized for pyogenic spondylitis, we found no association in the incidence of recurrence between PPS posterior fixation without anterior debridement and conservative treatment.

Who Needs Surgical Stabilization for Pyogenic Spondylodiscitis? Retrospective Analysis of Non-Surgically Treated Patients

STUDY DESIGN

Retrospective case series analysis.

OBJECTIVE

To identify relevant clinical and radiographic markers for patients presenting with infectious spondylo-discitis associated with spinal instability directly related to the infectious process.

METHODS

We evaluated patients presenting with de-novo intervertebral discitis or vertebral osteomyelitis /discitis (VOD) who initiated non-surgical treatment. Patients who failed conservative treatment and required stabilization surgery within 90 days were defined as "failed treatment group" (FTG). Patients who experienced an uneventful course served as controls and were labeled as "nonsurgical group" (NSG). A wide array of baseline clinical and radiographic parameters was retrieved and compared between 2 groups.

RESULTS

Overall 35 patients had initiated non-surgical treatment for VOD. 25 patients had an uneventful course (NSG), while 10 patients failed conservative treatment ("FTG") within 90 days. Factors found to be associated with poorer outcome were intra-venous drug abuse (IVDA) as well as the presence of fever upon initial presentation. Radiographically, involvement of the same-level facets and the extent of caudal and rostral VB involvement in both MRI and CT were found to be significantly associated with poorer clinical and radiographic outcome.

CONCLUSIONS

We show that clinical factors such as IVDA status and fever as well as the extent of osseous and posterior element involvement may prove to be helpful in favoring surgical treatment early on in the management of spinal infections.

A novel scoring system concept for de novo spinal infection treatment, the Spinal Infection Treatment Evaluation Score (SITE Score): a proof-of-concept study

OBJECTIVE

De novo infections of the spine are an increasing healthcare problem. The decision for nonsurgical or surgical treatment is often made case by case on the basis of physician experience, specialty, or practice affiliation rather than evidence-based medicine. To create a more systematic foundation for surgical assessments of de novo spinal infections, the authors applied a formal validation process toward developing a spinal infection scoring system using principles gained from other spine severity scoring systems like the Spine Instability Neoplastic Score, Thoracolumbar Injury Classification and Severity Score, and AO Spine classification of thoracolumbar injuries. They utilized an expert panel and literature reviews to develop a severity scale called the "Spinal Infection Treatment Evaluation Score" (SITE Score).

METHODS

The authors conducted an evidence-based process of combining literature reviews, extracting key elements from previous scoring systems, and obtaining iterative expert panel input while following a formal Delphi process. The resulting basic SITE scoring system was tested on selected de novo spinal infection cases and serially refined by an international multidisciplinary expert panel. Intra- and interobserver reliabilities were calculated using the intraclass correlation coefficient (ICC) and Fleiss' and Cohen's kappa, respectively. A receiver operating characteristic analysis was performed for cutoff value analysis. The predictive validity was assessed through cross-tabulation analysis.

RESULTS

The conceptual SITE scoring system combines the key variables of neurological symptoms, infection location, radiological variables for instability and impingement of neural elements, pain, and patient comorbidities. Ten patients formed the first cohort of de novo spinal infections, which was used to validate the conceptual scoring system. A second cohort of 30 patients with de novo spinal infections, including the 10 patients from the first cohort, was utilized to validate the SITE Score. Mean scores of 6.73 ± 1.5 and 6.90 ± 3.61 were found in the first and second cohorts, respectively. The ICCs for the total score were 0.989 (95% CI 0.975-0.997, p < 0.01) in the first round of scoring system validation, 0.992 (95% CI 0.981-0.998, p < 0.01) in the second round, and 0.961 (95% CI 0.929-0.980, p < 0.01) in the third round. The mean intraobserver reliability was 0.851 ± 0.089 in the third validation round. The SITE Score yielded a sensitivity of 97.77% ± 3.87% and a specificity of 95.53% ± 3.87% in the last validation round for the panel treatment decision.

CONCLUSIONS

The SITE scoring concept showed statistically meaningful reliability parameters. Hopefully, this effort will provide a foundation for a future evidence-based decision aid for treating de novo spinal infections. The SITE Score showed promising inter- and intraobserver reliability. It could serve as a helpful tool to guide physicians' therapeutic decisions in managing de novo spinal infections and help in comparison studies to better understand disease severity and outcomes.

Trends and characteristics of primary pyogenic spine infections among people who do and do not inject drugs: Northeast New York State, 2007 to 2018

Background:

Pyogenic spine infections (PSIs) are challenging to diagnose and treat. People who inject drugs (PWID) are at increased risk and contribute to rising PSI incidence.

Objective:

To analyze trends and characterize PSI in persons who do and do not inject drugs in northeast New York State (NYS), a predominantly rural region.

Methods:

A retrospective study of PSI patients at a regional tertiary care hospital from 2007 to 2018 was conducted. PSI incidence, population demographics, microbiology, surgical interventions, length of stay (LOS), and costs were compared between injection substance use disorder (ISUD) and non-ISUD cohorts.

Results:

Two hundred and seventy patients (59 ISUD and 211 non-ISUD) were included in this study. PSI incidence due to ISUD increased 1175% during the study time periods. The median age of the ISUD and non-ISUD cohorts was 39 and 65, respectively. Staphylococcus aureus was the most common causative organism, although a variety of bacterial and fungal pathogens were identified. Nearly half of the patients in each cohort required surgical intervention. Median acute care LOS was 12 days and comparable between cohorts. However, the ISUD cohort was frequently discharged against medical advice, or transferred back to acute care hospitals to complete antibiotic courses. Median inpatient hospital costs were approximately $25,000 and were comparable between cohorts. These costs do not reflect inpatient costs once the patient was transferred back to the referring hospital, nor costs for outpatient care. Medicaid and Medicare were the most common primary insurance payers for the ISUD and non-ISUD cohorts, respectively.

Conclusions:

Incidence of PSI has increased significantly coincident with the opioid epidemic and has had significant impact on a large, rural region of NYS. PSIs consume large amounts of healthcare resources. This study can inform hospitals and public health agencies regarding the need for substance abuse harm reduction strategies.

The Efficacy of Cannabis in Reducing Back Pain: A Systematic Review

OBJECTIVE

To critically analyze the evidence and efficacy of cannabis to treat surgical and nonsurgical back pain via a Systematic Review.

METHODS

We conducted a systematic review to investigate the efficacy of cannabis to treat non-surgical and surgical back pain. A literature search was performed with MEDLINE and Embase databases. Only RCTs and prospective cohort studies with concurrent control were included in this study. Risk of bias and quality grading was assessed for each included study.

RESULTS

Database searches returned 1738 non-duplicated results. An initial screening excluded 1716 results. Twenty-two full text articles were assessed for eligibility. Four articles ultimately met pre-determined eligibility and were included in the study. Two studies addressed post-SCI pain while other two studies addressed low back pain. No studies specifically examined the use of cannabis for surgical back pain. The type of cannabis varied between study and included THC, dronabinol, and Nabilone. A total of 110 patients were included in the four studies reviewed. In each study, there was a quantifiable advantage of cannabis therapy for alleviating back pain. There were no serious adverse effects reported.

CONCLUSIONS

In all articles, cannabis was shown to be effective to treat back pain with an acceptable side effect profile. However, long-term follow up is lacking. As medicinal cannabis is being used more commonly for analgesic effect and patients are "self-prescribing" cannabis for back pain, additional studies are needed for healthcare providers to confidently recommend cannabis therapy for back pain.

STUDY DESIGN

Systematic review.

Trends in Hospitalizations for Serious Infections Among People With Opioid Use Disorder in Ontario, Canada

Opioid use among people who inject drugs can lead to serious complications, including infections. We sought to study trends in rates of these complications among people with an opioid use disorder (OUD) and the sequelae of those hospitalizations.

Partnering With State Health Departments to Address Injection-Related Infections During the Opioid Epidemic: Experience at a Safety Net Hospital

Massachusetts is one of the epicenters of the opioid epidemic and has been severely impacted by injection-related viral and bacterial infections. A recent increase in newly diagnosed human immunodeficiency virus (HIV) infections among persons who inject drugs in the state highlights the urgent need to address and bridge the overlapping epidemics of opioid use disorder (OUD) and injection-related infections. Building on an established relationship between the Massachusetts Department of Public Health and Boston Medical Center, the Infectious Diseases section has contributed to the development and implementation of a cohesive response involving ambulatory, inpatient, emergency department, and community-based services. We describe this comprehensive approach including the rapid delivery of antimicrobials for the prevention and treatment of HIV, sexually transmitted diseases, systemic infections such as endocarditis, bone and joint infections, as well as curative therapy for chronic hepatitis C virus in a manner that is accessible to patients on the addiction-recovery continuum. We also provide an overview of programs that provide access to medications for OUD, harm reduction services including overdose education, and distribution of naloxone. Finally, we outline lessons learned to inform initiatives in other settings.

Operative Treatment of Adult Pyogenic Spondylodiscitis: A Retrospective Study of 32 Cases

Background Spondylodiscitis is a potentially life-threatening infection that imposes a significant financial burden on healthcare systems. Current reports suggest an increase in the incidence of spondylodiscitis, which could be attributed to the aging population and the growing rates of drug abuse. This study aims to evaluate the safety and effectiveness of surgical treatment of spondylodiscitis. Materials and methods Thirty-two cases diagnosed with spondylodiscitis and treated operatively between 2010 and 2015 were enrolled in this study. Indications for surgery were progressive neurologic involvement, progressive spinal deformity or instability, impending fracture, epidural abscess, and poor response to antibiotics. Patients underwent a single-stage procedure. A combined anterior and posterior approach was used in 28 of the patients. In 20 patients, a titanium mesh cage was used for reconstruction. The mean follow-up was 5.6 years. Results There were 18 males and 14 females. The mean age of the patients was 68.4 years (range 56-78). The cervical spine was affected in two cases (6.3%), the thoracic spine in 12 cases (37.5%), and the lumbar spine in 18 cases (56.3%). The most commonly isolated microorganisms were Staphylococcus aureus and Escherichia coli. There was neither mortality nor severe complications. Fusion was achieved in all the patients. There was complete resolution of the neurologic deficits that were recorded preoperatively. No signs of recurrent or residual infection were recorded until the last follow-up. Conclusions Our data suggest that early detection and surgical intervention of spondylodiskitis is associated with favorable outcomes.

The Surgical Treatment of Pyogenic Spondylodiscitis using Carbon-Fiber-Reinforced Polyether Ether Ketone Implants: Personal Experience of a Series of 81 Consecutive Patients

BACKGROUND

Pyogenic spondylodiscitis (PSD) is a complex disorder that often required postoperative imaging. Carbon-fiber-reinforced polyether ether ketone (CFRP) is radiolucent and offers an optimal assessability of anatomic structures.

METHODS

A retrospective file review of patients who were operated on for PSD using CFRP implants was performed to assess the clinical outcome, implant-associated complications, and revision surgery. A minimum follow-up of 3 months was required for evaluation of clinical and radiographic data, which included computed tomography and magnetic resonance imaging (MRI) assessment, to determine implant stability and assessability of soft tissue and nerve structures using a grading system.

RESULTS

Eighty-one consecutive patients with a mean of 69.5 years were identified. Debridement and stabilization were performed in 8 cervical, 17 thoracic, and 57 lumbar procedures; 72 interbody fusion procedures using cages were performed. Intraoperatively, no implant-associated complication was noted. The mean follow-up was 7 months, at which 52 patients attended. Improved mobility and reduced pain levels were reported by 87%, and MRI assessability was graded ideal. Residual sign of infection was seen in 5 cases, which influenced antibiotic therapy. Asymptomatic radiolucent zones were identified in 13 patients (16%) and screw loosening in 2 (2.4%). In 1 patient, the pedicle screw tip broke and remained within the vertebral body. A repeated procedure because of progressive vertebral body destruction, implant loosening, or subsidence was performed in 5 patients (6.1%).

CONCLUSIONS

The surgical treatment of PSD using CFRP is safe. The repeat procedure rate as a result of implant loosening is 6.1%. Minimal artifacts offer ideal assessability of soft tissue structures on an MRI.

Preoperative and Postoperative Opioid Dependence in Patients Undergoing Anterior Cervical Diskectomy and Fusion for Degenerative Spinal Disorders

BACKGROUND

 Anterior cervical diskectomy and fusion (ACDF) is a procedure for effectively relieving radiculopathy. Opioids are commonly overprescribed in postsurgical settings and prescriptions vary widely among providers. We identify trends in opioid dependence before and after ACDF.

METHODS

 We used the Truven Health MarketScan data to identify adult patients undergoing ACDF for degenerative cervical spine conditions between 2009 and 2015. Patients were segregated in four cohorts of preoperative and postoperative opioid nondependence (ND) or dependence (D) with 15 months of postoperative follow-up.

RESULTS

 A total of 25,403 patients with median age of 52 years (18-92) who underwent ACDF met the inclusion criteria. Breakdown of the four cohorts was as follows: prior nondependent who remain nondependent (NDND): 62.76% (n = 15,944); prior nondependent who become dependent (NDD): 4.6% (n = 1,168); prior dependent who become nondependent (DND): 14.03% (n = 3,564); and prior dependent who remain dependent (DD): 18.61% (n = 4,727). Opioid dependence decreased 9.43% postoperatively. Overall payments and 30-day readmissions increased 1.96 and 1.79 times for opioid dependent versus nondependent cohorts, respectively. Adjusted payments at 3 to 15 months were significantly increased for dependent cohorts with 3.56-fold increase for the DD cohort when compared with the NDND cohort. Length of stay, complications, medication refills, outpatient measures, and hospital admissions were also higher in those groups with postoperative opioid dependence when compared with those who were not opioid dependent.

CONCLUSIONS

 Opioid dependence after ACDF is associated with increased hospital readmissions, complication rates at 30 days, and payments within 3 months and 3 to 15 months postdischarge. Overall opioid dependence was decreased after ACDF procedure, however, a smaller number of opioid-dependent and opioid-naive patients became dependent postoperatively and should be followed carefully.

Antibiotic-impregnated polymethylmethacrylate strut graft as a treatment of spinal osteomyelitis: case series and description of novel technique

OBJECTIVE

The surgical treatment of osteomyelitis and discitis of the spine often represents a challenging clinical entity for a multitude of reasons, including progression of infection despite debridement, development of spinal deformity and instability, bony destruction, and seeding of hardware. Despite advancement in spinal hardware and implantation techniques, these aforementioned challenges not uncommonly result in treatment failure, especially in instances of heavy disease burden with enough bony endplate destruction as to not allow support of a modern titanium cage implant. While antibiotic-infused polymethylmethacrylate (aPMMA) has been used in orthopedic surgery in joints of the extremities, its use has not been extensively described in the spine literature. Herein, the authors describe for the first time a series of patients treated with a novel surgical technique for the treatment of spinal osteomyelitis and discitis using aPMMA strut grafts with posterior segmental fusion.

METHODS

Over the course of 3 years, all patients with spinal osteomyelitis and discitis at a single institution were identified and included in the retrospective cohort if they were surgically treated with spinal fusion and implantation of an aPMMA strut graft at the nidus of infection. Basic demographics, surgical techniques, levels treated, complications, and return to the operating room for removal of the aPMMA strut graft and placement of a traditional cage were examined. The surgical technique consisted of performing a discectomy and/or corpectomy at the level of osteomyelitis and discitis followed by placement of aPMMA impregnated with vancomycin and/or tobramycin into the cavity. Depending on the patient's condition during follow-up and other deciding clinical and radiographic factors, the patient may return to the operating room nonurgently for removal of the PMMA spacer and implantation of a permanent cage with allograft to ultimately promote fusion.

RESULTS

Fifteen patients were identified who were treated with an aPMMA strut graft for spinal osteomyelitis and discitis. Of these, 9 patients returned to the operating room for aPMMA strut graft removal and insertion of a cage with allograft at an average of 19 weeks following the index procedure. The most common infections were methicillin-sensitive Staphylococcus aureus (n = 6) and methicillin-resistant S. aureus (n = 5). There were 13 lumbosacral infections and 1 each of cervical and thoracic infection. Eleven patients were cured of their infection, while 2 had recurrence of their infection; 2 patients were lost to follow-up. Three patients required unplanned return trips to the operating room, two of which were for wound complications, with the third being for recurrent infection.

CONCLUSIONS

In cases of severe infection with considerable bony destruction, insertion of an aPMMA strut graft is a novel technique that should be considered in order to provide strong anterior-column support while directly delivering antibiotics to the infection bed. While the active infection is being treated medically, this structural aPMMA support bridges the time it takes for the patient to be converted from a catabolic to an anabolic state, when it is ultimately safe to perform a definitive, curative fusion surgery.

Expandable Titanium Cages in the Emergent Treatment of Severe Spinal Deformity Secondary to Osteomyelitis: A Series of Three Complex Cases

The literature lacks robust evidence on the benefits versus risks of instrumenting and fusing the spinal column in the setting of active osteomyelitis. We report three patients with vertebral osteomyelitis and subsequent severe and complex kyphotic deformities. Patients 1 and 2 had previous instrumentation that required revision because of hardware failure in the thoracic and thoracolumbar regions, respectively. Patient 3 developed a severe cervical kyphotic deformity at 2 months after being diagnosed and treated with antibiotics for osteomyelitis, necessitating emergent instrumentation and fusion. All the three patients are doing very well so far. Spinal instrumentation and fusion for correction of kyphotic deformity is sometimes necessary in the context of active osteomyelitis and should be done emergently and without hesitation when spinal cord injury from spinal instability is of concern.

Health Care Utilization and Payments of Postoperative and Drug Abuse-Related Spinal Infections

STUDY DESIGN

Retrospective analysis of data extracted from the MarketScan database (2000-2016) using International Classification of Diseases (ICD)-9, ICD-10, and Current Procedural Terminology-4 codes.

OBJECTIVE

Evaluate the economic costs and health care utilization associated with spine infections.

SUMMARY OF BACKGROUND DATA

Spinal infections (SI) are associated with significant morbidity and mortality. A recent spike in SI is attributed to the drug abuse epidemic. Management of SI represents a large burden on the health care system.

METHODS

We assessed payments and outcomes at the index hospitalization, 1-, 3-, 6-, and 12-month follow up. Outcomes assessed included length of stay, complications, operation rates, and health care utilization. Outcomes were compared between cohorts with spinal infections: (1) with prior surgery, (2) drug abuse, and (3) without previous exposure to surgery or drug abuse, denoted as control.

RESULTS

We identified 43,972 patients; 15.6% (N = 6847) of patients underwent prior surgery, 3.8% (N = 1,668) were previously expose to drug abuse while 80.6% fell into the control group. Both the postsurgical and drug abuse groups longer hospital stay compared with the control cohort (5 d vs. 4 d, P < 0.0001). Exposure to IV drug abuse was associated with increased risk of complications compared with the control group (43% vs. 38%, P < 0.0001). Payments at 1-month follow-up were significantly (P < 0.0001) higher among the postsurgical group compared with both groups. However, at 12-months follow-up, payments were significantly (P < 0.0001) higher in the drug abuse group compared with both groups. Only postsurgical infections were associated with higher number of surgical interventions both at presentation and 1 year follow up.

CONCLUSION

SI following surgery or IV drug abuse are associated with higher payments, complication rates, and longer hospital stays. Drug abuse related SI are associated with the highest complication rates, readmissions, and overall payments at 1 year of follow up despite the lower rate of surgical interventions.

LEVEL OF EVIDENCE

3.