Validation of ICD-10 Codes for the Identification of Paediatric Out-of-Hospital Cardiac Arrest Patients

Sociodemographic Factors and the Risk of Pediatric Out-of-Hospital Cardiac Arrest in Ontario, Canada: A Province-Wide Case-Control Study

BACKGROUND

Pediatric out-of-hospital cardiac arrest (POHCA) is associated with significant mortality and poor neurological outcomes. We aimed to describe the association between sociodemographic factors and POHCA risk in Ontario, Canada.

METHODS AND RESULTS

We conducted a province-wide case-control study at ICES, where patient records are linked across administrative databases. The case group included children (aged 1 day to 17 years) who experienced an out-of-hospital cardiac arrest between 2004 and 2020. Controls were matched up to 1:4 on age, sex, index date, and key comorbidities. We used conditional logistic regression to measure the association between sociodemographic indicators and POHCA risk. The case and control groups included 1826 and 7254 children, respectively. Children living in areas with the highest levels of material deprivation (adjusted odds ratio [aOR], 2.35 [95% CI, 1.94-2.85]) and dependency (aOR, 1.22 [95% CI, 1.01-1.48]) had a higher odds of POHCA, relative to children living in regions with the lowest levels of material deprivation and dependency, respectively. Children living in neighborhoods with the lowest levels of ethnic diversity had a higher odds of POHCA (aOR, 1.62 [95% CI, 1.30-2.01]), relative to children living in neighborhoods with the highest levels of ethnic diversity. The odds of POHCA were lower in immigrants (aOR, 0.67 [95% CI, 0.47-0.95]), relative to the general population. Northern urban residence was associated with a higher odds of POHCA (aOR, 1.45 [95% CI, 1.13-1.87]), relative to southern urban residence.

CONCLUSIONS

Children living in neighborhoods with high levels of marginalization may have an elevated risk of experiencing POHCA. These findings highlight the importance of addressing disparities through targeted prevention and intervention efforts.

Validation of ICD-10 codes for studying foreign body airway obstructions: A health administrative data cohort study

Aim

To validate a case definition for foreign body airway obstructions (FBAO) using International Classification of Diseases version 10 (ICD-10) codes to accurately identify patients in administrative health databases and improve reporting on this injury.

Methods

We identified prehospital patient encounters in Alberta, Canada between Jan 1, 2018 and Dec 31, 2021 by querying the provincial emergency medical services' (EMS) patient care records for FBAO-related presentations, EMS protocols, or treatments. We deterministically linked EMS patient encounters to data on emergency department visits and hospital admissions, which included ICD-10 codes. Two physicians independently reviewed encounters to determine true FBAO cases. We then calculated diagnostic accuracy measures (sensitivity, specificity, likelihood ratios) of various algorithms.

Results

We identified 3677 EMS patient encounters, 2121 were linked to hospital administrative databases. Of these encounters, 825 (38.9%) were true FBAO. The combination of two ICD-10 codes (T17 = foreign body in the respiratory tract or T18.0 = foreign body in the mouth) was the most specific algorithm (96.9% [95%CI 95.8-97.8%]), while the combination of all FBAO-related ICD-10 codes and R06.8 (other breathing abnormalities) was the most sensitive (75.0% [95%CI 71.9-78.0]). We identified an additional 453 (35.4%) FBAO cases not transported by EMS (due to death or transport refusal), and therefore not linked to the hospital administrative databases. Of these unlinked encounters, 44 (9.7%) cases resulted in the patient's death.

Conclusions

FBAO can be identified with reasonable accuracy using health administrative data and ICD-10 codes. All algorithms had a trade-off between sensitivity and specificity, and failed to identify a third of FBAO cases, of which 10% resulted in death.

Epidemiology of paediatric out-of-hospital cardiac arrest in Ontario, Canada

Background

There are no Canadian epidemiological studies of Paediatric Out-of-Hospital Cardiac Arrest (POHCA) for ≥20 years. Understanding the epidemiology of POHCA is key to prevention, education, and management strategies.

Methods

We applied a validated algorithm to hospital administrative databases to describe paediatric (age 1 day to ≤18 years) atraumatic OHCA in Ontario from 2004-2020.

Results

The cohort included 1,839 paediatric patients with atraumatic POHCA occurring at a median (IQR) age of 2 (0-12) years with 721 (39.2%) POHCA events in <1-year-olds. Males accounted for 71.1% (n = 1123) of the cohort. Crude incidence of children with POHCA who were transported to an Emergency Department was 4.2/100,000 with an increase annually over the study period (p = 0.0065). Thirty percent (n = 560) lived in a neighbourhood with the lowest income quintile, while 13.6% (n = 251) lived in a neighbourhood with the highest income quintile, 78.6% (n = 1444) presented to a non-academic hospital, and the majority (n = 1533, 83.4%) did not have significant comorbidities. Survival to hospital discharge was achieved in 167 (9.1%). Less than 6 (<3.6%) patients had a repeat POHCA in the year following the index event.

Conclusions

This is the largest Canadian POHCA cohort and the first to describe its incidence, comorbidities, and sociodemographic characteristics. We found an increase in annual crude incidence, POHCA mostly occurred in healthy children, and survival was similar to other cohorts. There were more than double the number of POHCA events in children living in the lowest income quintile neighborhoods compared to the highest. Most children presented to non-academic hospitals first.

Positive Predictive Value of ICD-10-CM Codes for Myocarditis in Claims Data: A Multi-Institutional Study in Taiwan

Purpose

The validity of the diagnosis codes to identify myocarditis cases in healthcare databases research remains unclear, and this study aimed to determine the coding accuracy of myocarditis in Taiwan.

Methods

We conducted a cross-sectional study based on Taiwan's largest multi-institutional healthcare system to identify inpatients newly diagnosed with ICD-10-CM myocarditis codes at discharge between January 1st, 2017 and March 31st, 2022. We ascertained the myocarditis diagnosis by a gold standard biopsy or by review of electronic medical records, and the positive predictive values (PPV) with 95% confidence intervals (CI) of the ICD-10-CM codes for myocarditis were determined.

Results

We included a total of 498 inpatients (mean age: 33.8 years old; female: 38.8%) with new myocarditis diagnosis at discharge. Codes I409 (30.1%) and I514 (45.4%) constituted the majority of myocarditis diagnostic codes in any coding position, and the overall PPV of the myocarditis codes was 73.5% (95% CI: 69.6-77.4%). However, the highest PPV (96.6%) for myocarditis diagnosis was noted with code I409 as the primary diagnosis. We found 132 inpatients (26.5%) who were false-positive myocarditis cases, identified by the ICD-10-CM codes, and potential reasons for misclassification included other inflammation diseases (n=35, 26.5%), pre-existing heart failure (n= 25, 18.9%) and acute myocardial infarction (n=16, 12.1%).

Conclusion

The PPV of ICD-10-CM codes for myocarditis in Taiwan was acceptable, but some other inflammation diseases and pre-existing heart diseases may be falsely coded as myocarditis. Our results may serve future secondary database studies as a fundamental reference on the validity of myocarditis diagnosis codes.

Validation of ICD-9-CM and ICD-10-CM Diagnostic Codes for Identifying Patients with Out-of-Hospital Cardiac Arrest in a National Health Insurance Claims Database

Purpose

Taiwan’s national health insurance (NHI) database is a valuable resource for large-scale epidemiological and long-term survival research for out-of-hospital cardiac arrest (OHCA). We developed and validated case definition algorithms for OHCA based on the International Classification of Diseases (ICD) diagnostic codes and billing codes for NHI reimbursement.

Patients and Methods

Claims data and medical records of all emergency department visits from 2010 to 2020 were retrieved from the hospital’s research-based database. Death-related diagnostic codes and keywords were used to identify potential OHCA cases, which were ascertained by chart reviews. We tested the performance of the developed OHCA algorithms and validated them on an external dataset.

Results

The algorithm defining OHCA as any cardiac arrest (CA)-related ICD code in the first three diagnosis fields performed the best with a sensitivity of 89.5% (95% confidence interval [CI], 88.2–90.7%), a positive predictive value (PPV) of 90.6% (95% CI, 89.4–91.8%), and a kappa value of 0.900 (95% CI, 0.891–0.909). The second-best algorithm consists of any CA-related ICD code in any diagnosis field with a billing code for triage acuity level 1, achieving a sensitivity of 85.6% (95% CI, 84.1–87.0%), a PPV of 93.6% (95% CI, 92.5–94.5), and a kappa value of 0.894 (95% CI, 0.884–0.903). Both algorithms performed well in external validation. In subgroup analyses, the former algorithm performed the best in adult patients, outpatient claims, and during the ICD-9 era. The latter algorithm performed the best in the inpatient claims and during the ICD-10 era. The best algorithm for identifying pediatric OHCAs was any CA-related ICD code in the first three diagnosis fields with a billing code for triage acuity level 1.

Conclusion

Our results may serve as a reference for future OHCA studies using the Taiwan NHI database.