key: cord-0947526-6sk71wjd
authors: Zhong, Haoyan; Poeran, Jashvant; Liu, Jiabin; Wilson, Lauren A.; Memtsoudis, Stavros G.
title: Hip Fracture Characteristics and Outcomes During COVID-19: A Large Retrospective National Database Review
date: 2021-04-15
journal: Br J Anaesth
DOI: 10.1016/j.bja.2021.04.003
sha: c86b73fefb0b9f516eb5a30d601e067895892c30
doc_id: 947526
cord_uid: 6sk71wjd

INTRODUCTION: The COVID-19 pandemic has impacted healthcare in various vulnerable patient subpopulations. However, data are lacking on COVID-19’s impact on hip fractures, seen mainly in elderly patients. Using national claims data, we aimed to describe the epidemiology during the first US COVID-19 wave in the United States. METHODS: We compared patients admitted for hip fractures during March and April of 2020 with those admitted in 2019 in terms of patient and healthcare characteristics, COVID-19 diagnosis, and outcomes. An additional comparison was made between COVID-19 positive and negative patients. Outcomes included length of hospital stay (LOS), admission to an intensive care unit (ICU), ICU LOS, use of mechanical ventilation, 30-day readmission, discharge disposition and a composite variable of post-operative complications. RESULTS: Overall, 16,068 hip fractures were observed in 2019 compared to 7,498 in 2020. Hip fracture patients in 2020 (compared to 2019), experienced earlier hospital discharge, were less likely to be admitted to ICU but more likely to be admitted to home. Among 83 hip fracture patients with concomitant COVID-19 diagnosis, we specifically observed more non-surgical treatments, almost doubled LOS, a more than 10-fold increased mortality rate, and higher complication rates, compared with COVID-19 negative patients. CONCLUSION: The COVID-19 pandemic significantly impacted not only volume of hip fractures but also patterns in care and outcomes. These results may inform policymakers in future outbreaks and how this may affect vulnerable patient populations such as those experiencing a hip fracture.

• COVID-19 has had major impacts on access to elective surgery, and complications in those undergoing elective and nonelective surgery 19) pandemic has caused a substantial strain on the United States healthcare system with various professional organizations, including the American Academy of Orthopedic Surgeons, providing guidance on postponement or cancellation of elective and nonurgent surgeries to slow the transmission of the disease, as well as to conserve healthcare resources. 1 Although these recommendations did not apply to urgent/emergent trauma surgeries, the shift of resources towards treating COVID-19 patients during the surge had the potential to leave the trauma system under-resourced. [2] [3] Many anaesthetists and operating practitioners were pulled away to cover intensive care units (ICU) resulting in reduced capacity for surgery and non-COVID-19 patient care. Despite observations that showed reduced emergency department admissions likely due to stay-at-home orders, 4-6 the necessity of caring for hip fractures in the elderly remained a concern. 7-8 In addition to potential resource shortages during the pandemic, hip fracture patients represent a very vulnerable population with multiple comorbidities 9 that is susceptible to respiratory infections due to the inability to ambulate. 10 Indeed, several studies have reported increased rate of severe complications, and high mortality rate among hip fracture patients with concomitant COVID-19 diagnosis. [11] [12] [13] [14] Despite these observations, it remains largely unknown how the first US COVID-19 wave impacted hip fracture volume, treatment options, and outcomes. Therefore, using a national database, this study aims to describe the epidemiology and compare patient and healthcare related characteristics and outcomes of hip fracture patients admitted during the COVID-19 outbreak with patients admitted during an identical pre-COVID-19 period.

Further, we sought to compare patient characteristics and outcomes between COVID-19 and non-COVID-19 hip fracture patients.

J o u r n a l P r e -p r o o f

This study was approved by the Institutional Review Board at the Hospital for Special Surgery (IRB#2012-050). The requirement for written informed consent was waived given the deidentified nature of the data. Patient information was derived from the Premier Healthcare database (Premier Healthcare Solutions, Inc., Charlotte, NC). 15 Individuals who were diagnosed with hip fracture upon hospital admission during March and April of 2019 and 2020 were queried. We selected patients admitted during the initial surge of COVID-19 from March 1 st to April 30 th in 2020, as these were the most recent data available to us at the time of analysis. In order to compare this cohort to controls, we selected patients admitted during the same time frame the year prior. This was done as fracture incidence and volume show seasonal variability. [16] [17] [18] Hip fracture codes were identified and further classified based on International Classification of Diseases, 10th Revision (ICD-10) diagnosis codes for the location of fracture: femoral neck (S72.0), intertrochanteric (S72.1), subtrochanteric (S72.2), or multiple locations. Hip fracture repair procedures were identified and classified into groups according to ICD-10 procedure codes: internal fixation, hemiarthroplasty, total hip arthroplasty (THA), or non-surgical (web supplement). Patients were excluded if they were <18 years old (N=382), pregnant (N=2), or missing gender information (N=5).

Variables of interest were patient and healthcare characteristics, COVID-19 diagnosis, and outcomes. Patient characteristics included age, gender, race (Black, White, or other), Charlson-J o u r n a l P r e -p r o o f Deyo comorbidity index 19 (categorised as 0, 1, 2, 3+), source of admission (Clinic, Transfer from other health facility, non-healthcare, others), admission type (elective, emergent/urgent/trauma, others), and insurance provider (commercial, Medicaid, Medicare, uninsured, unknown).

Fracture type and type of surgical procedure were classified as mentioned above. Healthcare characteristics analyzed included location (urban versus rural), size (<300 beds, 300-500 beds, 

All statistical analyses were performed using SAS version 9.4 (SAS Institute, Cary, NC).

Descriptive analyses were stratified by year, as well as by COVID-19 diagnosis within the 2020 cohort. Categorical variables were reported as absolute numbers and frequencies (%), and continuous variables were reported as median and interquartile range (IQR). Patient and healthcare characteristics were compared using standardised differences rather than P values, as univariable group differences easily reach statistical significance in large sample sizes. A standardised difference of 0.1 (or 10%) generally indicates a meaningful difference in covariate distribution between groups. 21 Odds ratios (ORs) are used to describe risk. Binary outcomes J o u r n a l P r e -p r o o f were compared using bivariate logistic regression, and continuous outcomes were compared using Wilcoxon-rank sum tests. A P value <0.05 was used to determine significant differences between 2020 and 2019. Given the descriptive nature of this paper, P values should be interpreted carefully.

Overall, 16,068 hip fractures were observed in 2019, compared to 7,498 (a 53% reduction) in 2020.

Absolute differences of patient and healthcare characteristics between 2019 and 2020 were relatively small, except for source of admission and teaching hospital, both with standardized differences of >0.1 (Table 1) . Regarding outcomes, patients with a hip fracture during the COVID-19 surge were discharged 1 day earlier (median [IQR]: 4 [3, 6] days) compared to the cohort admitted in 2019 (median [IQR]: 5 [3, 7] , P<0.001). In addition, patients were less likely to be admitted to an ICU postoperatively (OR 0.85 [95% CI 0.77, 0.93], P<0.001), and more likely to be discharged home (OR 1.57 [95% CI 1.47, 1.67], P<0.001). There were no differences between the 2 cohorts in 30-day readmission rates, use of mechanical ventilation, overall ICU days, or the incidence in composite complications ( Figure 1 ).

We identified 83 (1.1% of our 2020 cohort) patients with a hip fracture and concomitant COVID-19 diagnosis. Compared to non-COVID-19 patients, COVID-19 patients were more J o u r n a l P r e -p r o o f likely to be non-White, to have higher comorbidity burden, to be on emergent/urgent/trauma admission, to have Medicare/Medicaid insurance, to have pertrochanteric fracture, and to receive non-surgical treatments. COVID-19 patients were more commonly admitted to urban and teaching hospitals; the majority of COVID-19 patients were admitted in hospitals located in the northeast (69.9%). All standardised differences were >0.1 ( Table 2 ). Table 2 here We identified a significant reduction in the admission volume of hip fracture patients during the COVID-19 surge compared to the prior year. This finding may possibly in part be attributed to the lack of activity during the periods of the stay-at-home orders across the US. However, numerous studies reported that osteoporotic hip fractures remained unchanged during the COVID-19 pandemic. [7] [8] These studies represent large single institutional experiences which are possibly biased by the fact that many trauma patients were redirected to major centers, thus maintaining a relatively high volume at these locations. Consistent with this theory, our data shows that during the COVID-19 surge, hip fracture patients were more likely to be admitted to large teaching hospitals.

Interestingly, the outcomes associated with hip fracture care were not compromised despite the challenges hospitals faced during COVID-19 surge. [2] [3] We found that in-hospital mortality rate, 30-day readmission rate, use of mechanical ventilation, and complication rate were not different between during COVID-19 and pre-COVID-19 cohorts. Patients were discharged one day earlier, and had a lower chance of being admitted to ICU during COVID-19. While speculative, this may suggest an increased focus to expedite care and remove patients from potential at-risk environments such as hospitals. In addition, this finding may suggest that previous approaches to patient care in this cohort might be too conservative in the timing of discharge from the hospital.

Future studies are needed that may provide further insights into alternative approaches to discharge decisions after surgical repair of hip fractures. Similar reports regarding outcomes of earlier discharge, readmission rate as well as complication rates of hip-fracture patients during J o u r n a l P r e -p r o o f COVID-19 were published from a high-volume individual institution. 22 However, other institutions reported worse outcomes for hip fracture patients during COVID-19 pandemic.

Increased time from admission to surgical intervention (due to extensive COVID-19 testing protocols), lower availability of blood products, and limited operating room and staff capacity were commonly noticed in their practice. [23] [24] [25] [26] Even though the overall outcome of hip fracture patients during the pandemic remained similar with COVID-19 induced cytokine storm, can lead to serious complications including ARDS and multiple organ dysfunction. 27 Last but not least, older age and high comorbidity burden, which are common characteristics among hip fracture patients, are also associated with increased mortality of COVID-19.

There was no change in non-surgical approach and type of surgical repair observed in 2019 and 2020. Non-operative treatment of hip fractures requires longer recovery time, which increases the risk of pulmonary infection, pressure ulcers, urinary tract infection, lower limb venous thrombosis, and mortality. [28] [29] Mi and colleagues found, even though many hip fracture surgeries were delayed during COVID-19, patients with hip fractures were more likely to benefit from delayed surgery rather than non-operative therapy with decreased pain level, better function, and a lower likelihood of developing major complications. 30 However, we found that COVID-19positive hip fracture patients were more likely to be treated non-surgically. This is consistent with our finding that COVID positive patients experienced prolonged hospital stay. This finding may have numerous reasons, including lack of necessary resources, the avoidance of airway instrumentation, and a risk benefit analysis in an already at high risk population. Dupley and colleagues 31 also reported that COVID-19 patients were more likely to be deemed non-surgical and treated conservatively for hip fracture. Surgery can trigger excessive inflammation in COVID-19 patients, and decrease patients' immunity, increasing postoperative pulmonary complications. Therefore, considering the high mortality rate, some institutions recommended to carefully plan surgeries for COVID-19-positive hip fracture patients. 30 Our study has limitations. First, while Premier consists of data from approximately 20-25% of all hospital discharges in the US, 15 there are some patient populations that are not captured within the database (e.g., patients treated at Veterans Affairs hospitals). Second, the geographic level identifier in Premier is limited to region level, so we were not able to identify the "hotspots" during COVID-19, and control for its effect on patient outcome. Third, the relative difficulty of obtaining COVID testing in March and April 2020 may have resulted in some non-COVID cases actually being unrecognized COVID positive cases. Also, given the relatively small number of J o u r n a l P r e -p r o o f COVID positive patients, it is difficult to know how generalizable the present information is.

Fourth, the existing database does not contain long-term follow-up information of the COVID-19 cohort yet, so there may be long-term differences that were not yet captured by this study.

Lastly, hip fracture repair procedures were identified according to ICD-10 procedure codes. The number of non-operative repair may be overestimated.

The number of hip fracture cases during the COVID-19 surge decreased by 50% compared to the same time period in the previous year. Hip fracture patients during the pandemic were discharged earlier, and were less frequently to be admitted to ICU. In-hospital mortality rate, 30day readmission rate, use of mechanical ventilation, and complication rate were not different between COVID-19 pandemic period and pre-COVID-19 era. COVID-19-positive hip fracture patients had increased length of hospital stay, higher rates of perioperative complications, increased mortality rates, and more frequently received nonsurgical treatment. As our society returns to more normal levels of activity, hip fracture volumes are likely to increase to pre-surge levels. Healthcare institutions need to be prepared to manage these patients timely and safely, with special plans for caring for COVID-19 positive patients that experience a hip fracture, as well as protecting non-COVID-19 patients from in-hospital exposure. Furthermore, incidental findings of shorter hospital length of stay, less ICU utilisation, and more home discharge without compromising outcome deserve further study, with the question of whether pre-pandemic strategies in care for hip fracture patients should be adjusted. 

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Haoyan Zhong: This author helped in study design/planning, data analysis, interpretation of results, manuscript preparation, review and revision.Lauren A. Wilson: This author helped in study design/planning, data analysis, interpretation of results, manuscript preparation and review.Jiabin Liu: This author helped in study design/planning, interpretation of results, and manuscript review.Jashvant Poeran: This author helped in study design/planning, interpretation of results, manuscript preparation and review.