Background

Hirschsprung disease (or congentital aganglionic megacolon) is a birth defect that affects the functioning of the infant’s colon (part of the large intestine) due to missing nerve cells in the muscles. These nerve cells are important for the proper movement of stool through the bowel. When nerve cells are missing from areas of the colon, blockages can occur from slow or halted stool movement. Hirschsprung disease occurs in early pregnancy when nerve cells do not grow throughout the full length of a child’s bowel. Children are most often diagnosed shortly after birth when they present with signs of constipation, unresponsiveness to constipation medications, swelling of belly, fever, vomiting, and/or stunted growth. Treatment requires removal of part of the colon, which leaves most children feeling better and capable of living normal lives with only minor nutritional changes.[1]

About 20% of Hirschsprung disease cases occur in families where either a parent or sibling has the disease, while the remaining occur in people with no family history of the disorder. Therefore, genetics may play a small role in the occurrence of Hirschsprung disease. Currently, there is insufficient evidence for any environmental risk factors.[2]

Epidemiology

Alaska Birth Defects Registry (ABDR) registers birth defects as reported from health care providers using International Classification of Disease (ICD) billing codes. The use of these ICD codes can lead to misclassification of diagnosed conditions. Prior to this report, all prevalence estimates were based on the number of unique children reported to ABDR with an ICD code representing a specified condition regardless of case confirmation status.

The estimates in this report were derived by conducting medical record review and case confirmation of a random sample of cases of the condition reported to ABDR. The confirmation probability from the sample was used to develop informed estimates of the actual diagnosed defect prevalence. See Defect prevalence calculation.

For explanations of table columns see Column descriptions.

Prevalence

Hirschsprung disease occurs in about 2 out of every 10,000 live births in the United States.[1]

In Alaska, during 2007-2016, the prevalence of Hirschsprung was 3.5 per 10,000 live births.
Reports Defects Births Prevalence (95% CI)
Total 61 39.1 113183 3.5 (2.5, 4.7)
Notes: 95% CI = 95% Confidence Interval

Trend

Prevalence per 10,000 births of Hirschsprung during 2007-2016 by three-year moving averages, with 95% confidence interval band and Poisson estimated fitted line.
Reports Defects Births Prevalence (95% CI) Predicted Prevalence†
2007-2009 6.7 4.2 11262.0 3.7 (1.3, 8.6) 4.4
2008-2010 9.0 5.4 11404.3 4.8 (1.7, 9.8) 4.1
2009-2011 9.0 5.4 11404.7 4.8 (1.7, 9.8) 3.9
2010-2012 6.7 4.2 11354.0 3.7 (1.3, 8.6) 3.7
2011-2013 4.3 3.0 11348.7 2.6 (0.8, 7.3) 3.5
2012-2014 4.3 3.0 11334.3 2.6 (0.8, 7.3) 3.3
2013-2015 6.0 3.9 11377.0 3.4 (1.1, 8.1) 3.2
2014-2016 6.0 3.9 11295.0 3.4 (1.1, 8.2) 3.0
Notes: Each row is based on three-year moving averages; Prevalence reported per 10,000 live births; 95% CI=95% Confidence Interval

† Estimated rate based on Poisson model
The p-value test for trend detected no significant increase or decrease in the number of live births with Hirschsprung during 2007-2016. See p-value estimate
Estimate Std. Error t value Pr(>|t|)
-0.05408 0.02991 -1.80818 0.12058

Regional distribution

Distribution of Hirschsprung disease in Alaska by Public Health Region of maternal residence at the time of birth. A description of regional breakdowns can be found here.Data suppressed for # of reports < 6.
Reports Defects Births Prevalence (95% CI)
Anchorage 27 17.1 46323 0.4 (0.2, 0.6)
Gulf Coast - - 7048 -
Interior 7 5.0 20523 0.2 (0.1, 0.5)
Mat-Su - - 13587 -
Northern 11 6.2 7812 0.8 (0.4, 1.7)
Southeast - - 7012 -
Southwest 10 5.9 10878 0.5 (0.2, 1.1)
Notes:Prevalence reported per 10,000 live births; Data suppressed for # of reports < 6; 95% CI = 95% Confidence Interval

Demographics

Some subgroups may be more at risk for having a baby with Hirschsprung disease. This section provides the descriptive epidemiology of specified maternal, birth, and child characteristics identified from the birth certificate.

Reports Defects Births Prevalence (95% CI)
Sex
  Female 19 32.6 54900 0.6 (0.4, 0.8)
  Male 42 39.7 58283 0.7 (0.5, 0.9)
Birth weight (grams)
  <2500 12 6.1 6582 0.9 (0.4, 2.0)
  2500+ 49 66.1 106420 0.6 (0.5, 0.8)
Maternal age
  12-19 - - 8664 -
  20-24 11 18.3 30607 0.6 (0.4, 0.9)
  25-29 25 23.4 34376 0.7 (0.4, 1.0)
  30-34 12 15.8 25418 0.6 (0.4, 1.0)
  35-39 - - 11311 -
  40+ - - 2778 -
Maternal race
  Alaska Native/American Indian 27 21 28829 0.7 (0.5, 1.1)
  Asian/Pacific Islander - - 10598 -
  Black - - 4581 -
  White 25 40.6 67675 0.6 (0.4, 0.8)
Maternal education (years)
  <12 7 7.2 10904 0.7 (0.3, 1.3)
  12 19 25 40057 0.6 (0.4, 0.9)
  12+ 28 36.8 58944 0.6 (0.4, 0.8)
Marital status
  Married 36 45.2 71658 0.6 (0.5, 0.8)
  Unmarried 25 26.9 41006 0.7 (0.4, 0.9)
Maternal smoking use
  Reported smoking 18 12.2 15727 0.8 (0.4, 1.3)
  Reported not smoking 39 58.2 95579 0.6 (0.5, 0.8)
Medicaid (mother or child)
  Medicaid 43 39.4 57258 0.7 (0.5, 0.9)
  non-Medicaid 18 32.9 55806 0.6 (0.4, 0.8)
Father on birth certificate
  None - - 5634 -
  Present - - 107549 0.6 (0.5, 0.8)
Notes: Prevalence reported per 10,000 live births; Data suppressed for # of reports < 6; 95% CI = 95% Confidence Interval

Technical notes

Column descriptions

# Reports: Unless otherwise noted, the number of unique reports of the defect received by ABDR during the specified birth year(s). Each report represents a unique child with the specified defect.

# Defects: The estimated true number of reports that are diagnosed defects based on medical record review and case confirmation.

# Births: The number of live births among Alaskan residents that occurred in Alaska during the specified birth year(s).

Prevalence (95% CI): The estimated diagnosed prevalence of the condition and corresponding 95% Confidence Interval. (For information on how the defect prevalence was estimated see below).

Defect prevalence calculation

The estimated defect prevalence was calculated using a Bayesian approach based on the reported prevalence, PPV and 1-NPV (see formula below).

Through medical records review and case confirmation of a random sample of reported cases, the defect prevalence is calculated as:

\[PPV (Positive Predictive Value) = p(defect|report)\] \[NPV (Negative Predictive Value) = p(\overline{defect}|\overline{report})\]

\[p(defect) \approx [p(report)\cdot PPV]+[p(\overline{report})\cdot (1-NPV)]\]

Defect prevalence estimates are a more accurate estimation of the actual diagnosed prevalance of birth defects compared to the reported prevalance estimates in Alaska. ABDR obtains reports from medical providers using International Classification of Disease (ICD) codes that are extracted from individual systems which when aggregated may not reflect true diagnostics. Caution should be used when interpreting and comparing the reported prevalence estimates with national estimates.

See Data analysis methods for more information.

P-value estimate

To evaluate the trend over time and account for under/over-dispersion we constructed a quasi-Poisson regression model. This model assumes the variance is a linear function of the mean and models the estimated number of annual defects by year with a natural log (ln) offset of the annual births. P-values < 0.05 are considered significant, which indicates that the predicted slope is significantly different from a slope of zero.

Data suppression

For region and demographic data tables, values are suppressed based on the number of reports received during the observation period. Counts less than 6 are suppressed (as indicated by ‘-’ in the table). For regions or demographics with only one cell count suppressed a second is suppressed to eliminate the ability to back-calculate the estimate.

References

[1] NIH National Institute of Diabetes and Digestive and Kidney Diseases. Hirschsprung Disease, https://niddk.nih.gov/health-information/digestive-diseases/hirschsprung-disease; 2015 [accessed 03.31.2017]

[2] NIH U.S. National Library of Medicine. Genetics Home Reference: Hirschsprung Disease, https://ghr.nlm.nih.gov/condition/hirschsprung-disease.pdf; 2012 [accessed 03.31.2017]

Suggested Citation

State of Alaska Department of Health and Social Services, Division of Public Health, Section of Women’s, Children’s, and Family Health. Alaska Birth Defects Registry Condition Report: Hirschsprung, Alaska, 2007-2016. Updated July 28, 2020. Available at: http://rpubs.com/AK_ABDR/Hirschsprung07_16.

Contact

Alaska Birth Defects Registry (ABDR)
3601 C Street, Suite 358
Anchorage, AK 99503
(907) 269-3400 phone
(907) 754-3529 fax

Updated: July 28, 2020
Code source: R:\ABDR\Analysis_New\ABDR_CASECONF\cond_reports\Published_reports\Hirschsprung07_16.Rmd