Coding Variation and Adherence to Methodological Standards in Cardiac Research Using the National Inpatient Sample

Standardization of coding definitions for sickle cell disease complications: A systematic literature review

PURPOSE

Sickle cell disease (SCD) affects all organ systems and is characterized by numerous acute and chronic complications and comorbidities. Standardized codes are needed for complications/comorbidities used in real-world evidence (RWE) studies that rely on administrative and medical coding. This systematic literature review was conducted to produce a comprehensive list of complications/comorbidities associated with SCD, along with their diagnosis codes used in RWE studies.

METHODS

A search in MEDLINE and Embase identified studies published from 2016 to 2023. Studies were included if they were conducted in US SCD populations and reported complications/comorbidities and respective International Classification of Diseases, Clinical Modification (ICD-CM) codes. All identified complications/comorbidities and codes were reviewed by a certified medical coding expert and hematologist.

RESULTS

Of 1851 identified studies, 39 studies were included. The most reported complications/comorbidities were stroke, acute chest syndrome, pulmonary embolism, venous thromboembolism, and vaso-occlusive crisis. Most of the studies used ICD-9-CM codes (n = 21), while some studies used ICD-10-CM codes (n = 3) or both (n = 15), depending on the study period. Most codes reported in literature were heterogeneous across complications/comorbidities. The medical coding expert and hematologist recommended modifications for several conditions.

CONCLUSION

While many studies we identified did not report their codes and were excluded from this review, the studies with codes exhibited diverse coding definitions. By providing a standardized set of diagnosis codes that were reported by studies and reviewed by a coding expert and hematologist, our review can serve as a foundation for accurately identifying complications/comorbidities in future research, and may reduce heterogeneity, enhance transparency, and improve reproducibility. Future efforts focused on validating these code lists are needed.

Disparities by sex, race, and region in acute myocardial infarction-related outcomes during the early COVID-19 pandemic: the national inpatient sample analysis

BACKGROUND

Disparities in acute myocardial infarction (AMI)-related outcomes have been reported before the COVID-19 pandemic. We studied in-hospital outcomes of AMI across demographic groups in the United States during the early COVID-19 pandemic.

METHODS

The National Inpatient Sample (NIS) database was queried for 2020 to identify AMI-related hospitalizations based on appropriate ICD-10-CM codes categorized by sex, race, and hospital region categories. The primary outcome was in-hospital mortality in females, racial and ethnic minority groups, and Northeast hospital region compared with males, White patients, and Midwest hospital region, respectively. Multivariable regression analysis was used to calculate the adjusted odds ratio and mean difference.

RESULTS

A total of 820,893 AMI-related hospitalizations were identified during the study period. On adjusted analysis, during the early COVID-19 pandemic, females had lower odds of in-hospital mortality [aOR 0.89 (0.85-0.92); P < 0.01] and revascularization [aOR 0.68 (0.66-0.69); P < 0.01] than males. Racial and ethnic based analysis showed that Asian/Pacific Islander patients had higher odds of in-hospital mortality [aOR 1.13 (1.03-1.25); P < 0.01] than White patients. During the early COVID-19 pandemic, Northeast and Western region hospitals had higher odds of in-hospital mortality, lower odds of revascularization, longer length of stay, and higher total hospitalization costs than Midwest region hospitals.

CONCLUSIONS

Our study disclosed disparities in AMI-related mortality and revascularization by sex, race and ethnic, and region during the early COVID-19 pandemic. Special attention should be given to at-risk populations. Whether these disparities continue in the post-vaccination era warrants further study.

Obesity is associated with acute kidney injury in ST-segment-elevation myocardial infarction undergoing percutaneous coronary intervention: A national representative cohort study

BACKGROUND

Acute kidney injury (AKI) is a frequent and potentially life-threatening complication after percutaneous coronary intervention (PCI) in patients with ST-segment-elevation myocardial infarction (STEMI). However, the relationship between obesity and the risk of AKI in this specific patient population has not been previously examined.

METHODS

We queried the National Inpatient Sample (2016-2019) using ICD-10 codes to obtain a sample of adults with STEMI undergoing PCI. All patients were further subcategorized into obese and nonobese cohorts. The primary outcome was the incidence of AKI. Multivariate regression analysis was performed to assess the impact of obesity on AKI. The consistency of this correlation between subgroups was investigated using subgroup analysis and interaction testing.

RESULTS

A total of 62,599 (weighted national estimate of 529,016) patients were identified, of which 9.80% (n = 6137) had AKI. Obesity comprised 19.78% (n = 1214) of the AKI cohort. Obese patients were on average younger, male, white, and had more comorbidities. Additionally, there was a significant positive association between obesity and AKI incidence (adjusted odds ratio [aOR]: 1.24, 95% confidence interval [CI]: 1.15-1.34), which was more pronounced in female patients (aOR: 1.56, 95% CI: 1.33-1.82, p < 0.001, p-interaction = 0.008). The AKI incidence in these patients increased steadily during the 4-year study period, and it was consistently higher in obese patients than in nonobese patients (p-trend < 0.001 for all).

CONCLUSIONS

Obesity was independently associated with a greater risk of AKI among adults with STEMI undergoing PCI, particularly in female patients.

Cerebrovascular Disease Hospitalization Rates in End-Stage Kidney Disease Patients with Kidney Transplant and Peripheral Vascular Disease: Analysis Using the National Inpatient Sample (2005-2019)

Individuals with end-stage kidney disease (ESKD) face higher cerebrovascular risk. Yet, the impact of peripheral vascular disease (PVD) and kidney transplantation (KTx) on hospitalization rates for cerebral infarction and hemorrhage remains underexplored. Analyzing 2,713,194 ESKD hospitalizations (2005-2019) using the National Inpatient Sample, we investigated hospitalization rates for ischemic and hemorrhagic cerebrovascular diseases concerning ESKD, PVD, KTx, or their combinations. Patients hospitalized with cerebral infarction due to thrombosis/embolism/occlusion (CITO) or artery occlusion resulting in cerebral ischemia (AOSI) had higher rates of comorbid ESKD and PVD (4.17% and 7.29%, respectively) versus non-CITO or AOSI hospitalizations (2.34%, p < 0.001; 2.29%, p < 0.001). Conversely, patients hospitalized with nontraumatic intracranial hemorrhage (NIH) had significantly lower rates of ESKD and PVD (1.64%) compared to non-NIH hospitalizations (2.34%, p < 0.001). Furthermore, hospitalizations for CITO or AOSI exhibited higher rates of KTx and PVD (0.17%, 0.09%, respectively) compared to non-CITO or AOSI hospitalizations (0.05%, p = 0.033; 0.05%, p = 0.002). Patients hospitalized with NIH showed similar rates of KTx and PVD (0.04%) versus non-NIH hospitalizations (0.05%, p = 0.34). This nationwide analysis reveals that PVD in ESKD patients is associated with increased hospitalization rates with cerebral ischemic events and reduced NIH events. Among KTx recipients, PVD correlated with increased hospitalizations for ischemic events, without affecting NIH. This highlights management concerns for patients with KTx and PVD.

Prediction of clinical outcomes after percutaneous coronary intervention: Machine-learning analysis of the National Inpatient Sample

BACKGROUND

This study aimed to develop a multiclass machine-learning (ML) model to predict all-cause mortality, ischemic and hemorrhagic events in unselected hospitalized patients undergoing percutaneous coronary intervention (PCI).

METHODS

This retrospective study included 1,815,595 unselected weighted hospitalizations undergoing PCI from the National Inpatient Sample (2016-2019). Five most common ML algorithms (logistic regression, support vector machine (SVM), naive Bayes, random forest (RF), and extreme gradient boosting (XGBoost)) were trained and tested with 101 input features. The study endpoints were different combinations of all-cause mortality, ischemic cerebrovascular events (CVE) and major bleeding. An area under the curve (AUC) with 95% confidence interval (95% CI) was selected as a performance metric.

RESULTS

The study population was split to a training cohort of 1,186,880 PCI discharges, validation cohort (for calibration) of 296,725 hospitalizations and a test cohort of 331,990 PCI discharges. A total of 98,180 (5.4%) hospital entries included study outcomes. Logistic regression, SVM, naive Bayes, and RF model demonstrated AUCs of 0.83 (95% CI 0.82-0.84), 0.84 (95% CI 0.83-0.86), 0.81 (95% CI 0.80-0.82), and 0.83 (95% CI 0.81-0.84), retrospectively. The XGBoost classifier performed the best with an AUC of 0.86 (95% CI 0.85-0.87) with excellent calibration. We then built a web-based application that provides predictions based on the XGBoost model.

CONCLUSION

We derived the multi-task XGBoost classifier based on 101 features to predict different combinations of all-cause death, ischemic CVE and major bleeding. Such models may be useful in benchmarking and risk prediction using routinely collected administrative data.

Complications Associated With Transesophageal Echocardiography in Transcatheter Structural Cardiac Interventions

BACKGROUND

Transesophageal echocardiograms (TEEs) performed during transcatheter structural cardiac interventions may result in greater complications than those performed in the nonoperative setting or even those performed during cardiac surgery. However, there are limited data on complications associated with TEE during these procedures. We evaluated the prevalence of major complications among these patients in the United States.

METHODS

A retrospective cohort study was conducted using an electronic health record database (TriNetX Research Network) from large academic medical centers across the United States for patients undergoing TEE during transcatheter structural interventions from January 2012 to January 2022. Using the American Society of Echocardiography-endorsed International Statistical Classification of Diseases and Related Health Problems Clinical Modifications (10th edition) codes, patients undergoing TEE during a transcatheter structural cardiac intervention, including transaortic, mitral or tricuspid valve repair, left atrial appendage occlusion, atrial septal defect closure, patent foramen ovale closure, and paravalvular leak repair, were identified. The primary outcome was major complications within 72 hours of the procedure (composite of bleeding and esophageal and upper respiratory tract injury). The secondary aim was the frequency of major complications, death, or cardiac arrest within 72 hours in patients who completed intraoperative TEE during surgical valve replacement.

RESULTS

Among 12,043 adult patients (mean age, 74 years old; 42% female) undergoing TEE for transcatheter structural cardiac interventions, 429 (3.6%) patients had a major complication. Complication frequency was higher in patients on anticoagulation or antiplatelet therapy compared with those not on therapy (3.9% vs 0.5%; risk ratio [RR] = 8.09, P < .001). Compared with those patients <65 years of age, patients ≥65 years of age had a higher frequency of major complications (3.9% vs 2.2%; RR = 1.75, P < .001). Complication frequency was similar among male and female patients (3.5% vs 3.7%; RR = 0.96, P = .67). Among 28,848 patients who completed surgical valve replacement with TEE guidance, 728 (2.5%) experienced a major complication.

CONCLUSIONS

This study found that more than 3% of patients undergoing TEE during transcatheter structural cardiac interventions have a major complication, which is more common among those on anticoagulant or antiplatelet therapy or who are elderly. With a shift of poor surgical candidates to less invasive percutaneous procedures, the future of TEE-guided procedures relies on comprehensive risk discussion and updating practices beyond conventional methods to minimize risk for TEE-related complications.

Male and female mortality rates due to acute types of coronary artery disease in five-year age groups in the Russian Federation: what do the numbers mean?

Aim. To assess mortality rates due to acute types of coronary artery disease (CAD) in five-year age groups (20-85+ years) and the contribution to all-cause mortality in 2019-2020.

Material and methods. From the Center for Demographic Research of the Russian Economic School, data on all-cause and acute CAD mortality rates were selected (codes: I21.0-9; I22.0-9; I20, I24.1-9) in five-year age groups (from 20-24 years to the group 85+ inclusive) of men and women per 1 million population in 2019 and 2020. The contribution (in %) of acute types of CAD to all-cause mortality, the contribution of each disease to mortality, and the ratio of male/female mortality rates were determined.

Results. The contribution of all acute types of CAD to all-cause mortality among men of different 5-year age groups ranges from 1,2 to 7,9% (50-54 years), among women from 0,9 to 5,5% (65-69 years) and has the character parabolic dependence on age. In each subsequent 5-year age groups, mortality rates due to acute CAD is higher compared to the previous one. However, in age groups up to 60 years, the share of "other forms of acute CAD" prevails (from 51% to 100%), and after 60 years — myocardial infarction (MI) (from 56% to 78%). For all acute types of CAD in 2019-2020, mortality rate among men is higher than among women: a maximum of 25 times from recurrent MI in age group of 40-44 years in 2020; 7 times — from acute MI in age group of 40-44 years in 2019; and 4,5 times from "other forms of acute CAD" in age group of 50-54 years in 2019. In 2020, compared to 2019, there was an increase in mortality from all acute CAD, with the exception of age group of 25-29 years among women and 20-34 years among men.

Conclusion. The identified structural age-sex features of mortality from acute CAD may be due to approaches to diagnosis and identification of various CAD forms as the cause of death and require the creation in the Russian Federation of a methodological protocol or algorithm for determining the cause of death of various acute types of CAD.

The Impact of Concomitant Diagnosis of Viral Infections on in-Hospital Mortality in Patients Hospitalized with a Diagnosis of Heart Failure in the United States: Insights from the National Inpatient Sample

The impact of viral infections on patients admitted with a diagnosis of heart failure is not well understood. We conducted a retrospective cohort study using data from the National Inpatient Sample in the United States to evaluate the proportion of admissions with a diagnosis of heart failure and viral infections, and we explored how viral infections had impact on in-hospital mortality and length of stay. There were a total of 20,713,539 admission records with a diagnosis of heart failure included in the analysis and 3.8% had a concomitant diagnosis of viral infection. The mean length of stay was 20.1 ± 26.9 days, 12.9 ± 13.6 days, 12.1 ± 13.8 days, and 5.1 ± 6.5 days for records with a diagnosis of cytomegalovirus, viral meningitis/encephalitis, herpes simplex infection, and no viral infection, respectively. The most common diagnoses of viral infections were influenza (n = 240,260) and chronic viral hepatitis (n = 194,400), and the highest rates of mortality were observed for records with a diagnosis of cytomegalovirus (13.2%), acute viral hepatitis (12.5%), and viral meningitis/encephalitis (11.1%). The viral infections significantly associated with increased odds of mortality were cytomegalovirus infection (OR 1.84 95% CI 1.57-2.16), acute hepatitis (OR 1.29 95% CI 1.15-1.45), and HIV (OR 1.22 95% CI 1.11-1.34). In conclusion, viral infections are co-diagnosis in 3.8% of patient records with heart failure and detection of some viruses may be important as they increase mortality and may prolong length of stay in hospital.