Validation of algorithms to determine incidence of Hirschsprung disease in Ontario, Canada: a population-based study using health administrative data

Evaluating the coding accuracy of type 2 diabetes mellitus among patients with non-alcoholic fatty liver disease

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) describes a spectrum of chronic fattening of liver that can lead to fibrosis and cirrhosis. Diabetes has been identified as a major comorbidity that contributes to NAFLD progression. Health systems around the world make use of administrative data to conduct population-based prevalence studies. To that end, we sought to assess the accuracy of diabetes International Classification of Diseases (ICD) coding in administrative databases among a cohort of confirmed NAFLD patients in Calgary, Alberta, Canada.

METHODS

The Calgary NAFLD Pathway Database was linked to the following databases: Physician Claims, Discharge Abstract Database, National Ambulatory Care Reporting System, Pharmaceutical Information Network database, Laboratory, and Electronic Medical Records. Hemoglobin A1c and diabetes medication details were used to classify diabetes groups into absent, prediabetes, meeting glycemic targets, and not meeting glycemic targets. The performance of ICD codes among these groups was compared to this standard. Within each group, the total numbers of true positives, false positives, false negatives, and true negatives were calculated. Descriptive statistics and bivariate analysis were conducted on identified covariates, including demographics and types of interacted physicians.

RESULTS

A total of 12,012 NAFLD patients were registered through the Calgary NAFLD Pathway Database and 100% were successfully linked to the administrative databases. Overall, diabetes coding showed a sensitivity of 0.81 and a positive predictive value of 0.87. False negative rates in the absent and not meeting glycemic control groups were 4.5% and 6.4%, respectively, whereas the meeting glycemic control group had a 42.2% coding error. Visits to primary and outpatient services were associated with most encounters.

CONCLUSION

Diabetes ICD coding in administrative databases can accurately detect true diabetic cases. However, patients with diabetes who meets glycemic control targets are less likely to be coded in administrative databases. A detailed understanding of the clinical context will require additional data linkage from primary care settings.

Validation of case definition algorithms for the ascertainment of congenital anomalies

BACKGROUND

Congenital anomalies (CA) are one of the leading causes of infant mortality and long-term disability. Many jurisdictions rely on health administrative data to monitor these conditions. Case definition algorithms can be used to monitor CA; however, validation of these algorithms is needed to understand the strengths and limitations of the data. This study aimed to validate case definition algorithms used in a CA surveillance system in British Columbia (BC), Canada.

METHODS

A cohort of births between March 2000 and April 2002 in BC was linked to the Health Status Registry (HSR) and the BC Congenital Anomalies Surveillance System (BCCASS) to identify cases and non-cases of specific anomalies within each surveillance system. Measures of algorithm performance were calculated for each CA using the HSR as the reference standard. Agreement between both databases was calculated using kappa coefficient. The modified Standards for Reporting Diagnostic Accuracy guidelines were used to enhance the quality of the study.

RESULTS

Measures of algorithm performance varied by condition. Positive predictive value (PPV) ranged between approximately 73%-100%. Sensitivity was lower than PPV for most conditions. Internal congenital anomalies or conditions not easily identifiable at birth had the lowest sensitivity. Specificity and negative predictive value exceeded 99% for all algorithms.

CONCLUSION

Case definition algorithms may be used to monitor CA at the population level. Accuracy of algorithms is higher for conditions that are easily identified at birth. Jurisdictions with similar administrative data may benefit from using validated case definitions for CA surveillance as this facilitates cross-jurisdictional comparison.

Hirschsprung-associated inflammatory bowel disease: A multicenter study from the APSA Hirschsprung disease interest group

BACKGROUND/PURPOSE

A small number of Hirschsprung disease (HD) patients develop inflammatory bowel disease (IBD)-like symptoms after pullthrough surgery. The etiology and pathophysiology of Hirschsprung-associated IBD (HD-IBD) remains unknown. This study aims to further characterize HD-IBD, to identify potential risk factors and to evaluate response to treatment in a large group of patients.

METHODS

Retrospective study of patients diagnosed with IBD after pullthrough surgery between 2000 and 2021 at 17 institutions. Data regarding clinical presentation and course of HD and IBD were reviewed. Effectiveness of medical therapy for IBD was recorded using a Likert scale.

RESULTS

There were 55 patients (78% male). 50% (n = 28) had long segment disease. Hirschsprung-associated enterocolitis (HAEC) was reported in 68% (n = 36). Ten patients (18%) had Trisomy 21. IBD was diagnosed after age 5 in 63% (n = 34). IBD presentation consisted of colonic or small bowel inflammation resembling IBD in 69% (n = 38), unexplained or persistent fistula in 18% (n = 10) and unexplained HAEC >5 years old or unresponsive to standard treatment in 13% (n = 7). Biological agents were the most effective (80%) medications. A third of patients required a surgical procedure for IBD.

CONCLUSION

More than half of the patients were diagnosed with HD-IBD after 5 years old. Long segment disease, HAEC after pull through operation and trisomy 21 may represent risk factors for this condition. Investigation for possible IBD should be considered in children with unexplained fistulae, HAEC beyond the age of 5 or unresponsive to standard therapy, and symptoms suggestive of IBD. Biological agents were the most effective medical treatment.

LEVEL OF EVIDENCE

Level 4.

Hirschsprung's disease in low- and middle-income countries

Hirschsprung's disease (HD) is one of the most common causes of pediatric bowel obstruction in low- and middle-income countries (LMICs). This paper describes the unique aspects of presentation, diagnosis, management and post-operative care and outcomes of HD in LMICs. In LMICs, patients with HD are much more likely to present in a delayed fashion with subsequent increased morbidity and mortality including higher rates of chronic obstruction, malnutrition with failure to thrive, complete obstruction and perforation. There are multifactorial causes for delay, with opportunities to improve initial timely diagnosis and referral, support families to address socioeconomic and cultural barriers, and improve workforce and infrastructure resources to provide definitive care. In LMICs, the diagnosis is often made based on clinical presentation and radiographic findings as pathological services may be limited. Initial diversion with multi-stage procedure, instead of a single-stage pull-through, predominates. This is also a result of multifactorial causes, including initial presentation to general surgeons at first-level hospitals instead of pediatric surgeons, delayed presentation with sick, malnourished children with significantly distended bowel, and a lack of fresh-frozen pathological services to guide the extent of resection. Post-operatively, HD patients in LMICs experience higher complication and mortality rates - likely stemming from sicker baseline presentations and more limited resources. Significant recent advances in care have occurred for patients with HD in LMICs, while opportunities to continue to improve care remain.

Increased Incidence of Inflammatory Bowel Disease After Hirschsprung Disease: A Population-based Cohort Study

OBJECTIVE

To determine the frequency with which inflammatory bowel disease (IBD) is diagnosed in persons with Hirschsprung disease in population-based datasets from 3 Canadian provinces.

STUDY DESIGN

In study I, Ontario data were used to assess the incidence of IBD in a birth cohort of children with Hirschsprung disease relative to children without Hirschsprung disease. In study II, a case-control design was used in Alberta and Manitoba to determine the frequency of previously diagnosed Hirschsprung disease in persons with IBD, compared with the frequency of Hirschsprung disease in matched controls. Validated algorithms for Hirschsprung disease and IBD were applied to each provincial health registry.

RESULTS

In study I, of the 716 children diagnosed with Hirschsprung disease in Ontario since 1991, 18 (2.5%) ultimately developed IBD (168.8 per 100 000 person-years), compared with 7109 of 3 377 394 children without Hirschsprung disease (0.2%, 14.2 per 100 000 person-years). The percentage of males with post-Hirschsprung disease IBD was 77.8%. The incidence rate ratio was 11.9 (95% CI, 7.5-18.8). In study II, the OR of having had Hirschsprung disease before a diagnosis of IBD compared with controls was 74.9 (95% CI, 17.1-328.7) in Alberta and 23.8 (95% CI, 4.6-123) in Manitoba. Crohn's disease was more common after Hirschsprung disease than ulcerative colitis.

CONCLUSIONS

IBD can emerge in more than 2% of patients with Hirschsprung disease and, like Hirschsprung disease itself, is more common in males. IBD is much more common after a diagnosis of Hirschsprung disease than in the general population.

Long-term Outcomes of Patients Surgically Treated for Hirschsprung Disease

Background

The only curative treatment for Hirschsprung disease (HD) is surgical repair. However, some patients experience poor postoperative outcomes. We determined long-term outcomes of all HD patients in Ontario, Canada’s most populous province.

Methods

We conducted a retrospective cohort study including all children with HD born between April 1, 1991 and March 31, 2014 in Ontario using linked health administrative data. Each HD case was matched to five non-HD controls on sex, date of birth, region of residence and income and followed to March 31, 2016. Chronic diarrhea and constipation were identified using combinations of outpatient physician billing codes in both HD patients and non-HD residents of the province. We determined risk factors associated with diarrhea and constipation, including surgery type and sociodemographic characteristics, using multivariable conditional logistic regression, and reported adjusted odds ratios (aORs).

Results

There were 3,265,172 children born in the study period, of whom 673 had HD. Compared to controls, chronic constipation was more common in HD patients (27.5% versus 2.1%; aOR 17.2, 95% CI 12.6 to 23.4), as was chronic diarrhea (29.9% versus 6.9%, aOR 5.22, 95% CI 4.19 to 6.50). In HD patients, older age at surgery was associated with increased risk of chronic constipation (OR 2.71, 95% CI 1.75 to 4.20). Surgery type, sex, rural/urban residence and income were not associated with risk of chronic constipation or diarrhea.

Conclusion

Chronic constipation and diarrhea were common following surgery for HD. Older age at surgery was associated with subsequent risk of chronic constipation. Surgery type was not associated with increased risk of chronic constipation or diarrhea.

Development and validation of an algorithm of diagnostic and procedural codes for the identification of children hospitalized with a tracheostomy in Ontario, Canada

BACKGROUND

The requirement for a tracheostomy in children is associated with significant morbidity, mortality, and healthcare utilization. Easy identification of children with tracheostomies would facilitate important research on this population and provide quality improvement initiatives.

AIM

The purpose of this study is to determine whether an algorithm of diagnostic and procedural codes can accurately identify children hospitalized with a tracheostomy using routinely collected health data.

METHODS

Chart reviews were performed at the Children's Hospital of Eastern Ontario (CHEO) and the London Health Sciences Center (LHSC) to establish a true positive cohort of pediatric patients with tracheostomies admitted between 2008 and 2016. A multidisciplinary team developed algorithms of diagnostic and procedural codes contained within the Canadian Institute for Health Information Discharge Abstract Database. Algorithms were tested and refined against the true-positive and true-negative cohort. The accuracy of the diagnostic codes related to tracheostomy complications was also evaluated.

RESULTS

A chart review identified 158 unique children with tracheostomies (77 at CHEO, 81 at LHSC) with 901 individual admissions (401 at CHEO, 507 at LHSC). The best algorithms for identifying children with a tracheostomy had a sensitivity and specificity of more than 99%, a positive predictive value (PPV) of 94.0% and negative predictive value (NPV) of 100%. The algorithm for the identification of tracheostomy-related complications had a sensitivity of 76.7%, a specificity of 65%, PPV of 52.3%, and an NPV of 84.7%.

CONCLUSIONS

This study provides an algorithm for the accurate identification of children hospitalized in Canada with a tracheostomy, facilitating population-level epidemiological research and quality improvement initiatives.

Epidemiology of Hirschsprung disease in California from 1995 to 2013

PURPOSE

This study seeks to update current epidemiology of Hirschsprung disease (HD) in California.

METHODS

Using data from the California Office of Statewide Health Planning and Development Linked Birth (1995-2012) and Patient Discharge Databases (1995-2013), patients from either dataset with an ICD-9 diagnosis code of HD (751.3) or procedure code of Soave (48.41), Duhamel (48.65), or Swenson/other pull-through (48.49) were included. Patients > age 18 during their first admission were excluded.

RESULTS

Of 9.3 million births, 2,464 patients were identified. Incidence was 2.2 cases/10,000 live births, with rates peaking at 2.9/10,000 births in 2002. Incidence was highest among African American (4.1/10,000) and Asian/Pacific Islander (2.5/10,000) births. Most were male (n = 1652, 67.1%). Sixty patients (2.4%) had Down syndrome. The median gestational age at birth was 38 weeks 6 days (interquartile range [IQR] 37 weeks 1 day-40 weeks 1 day). Mortality during the first year of life was 1.7%. Median age at death was 14.5 days (IQR 0-113 days).

CONCLUSION

This is one of the largest population-based studies of HD. In California, the incidence of HD is stable, risk is highest among African American children, and the mortality rate is < 2%.