Hospitalizations for Inflammatory Bowel Disease Among Medicare Fee-for-Service Beneficiaries — United States, 1999–2017

Crohn’s disease and ulcerative colitis, collectively referred to as inflammatory bowel disease (IBD), are conditions characterized by chronic inflammation of the gastrointestinal tract. The incidence and prevalence of IBD is increasing globally, and although the disease has little impact on mortality, the number of older adults with IBD is expected to increase as the U.S. population ages (1). Older adults with IBD have worse hospitalization outcomes than do their younger counterparts (2). CDC analyzed Medicare Provider Analysis and Review (MedPAR) data to estimate IBD-related hospitalization rates and hospitalization outcomes in 2017 among Medicare fee-for-service beneficiaries aged ≥65 years, by selected demographics and trends in hospitalization rates and by race/ethnicity during 1999–2017. In 2017, the age-adjusted hospitalization rate for Crohn’s disease was 15.5 per 100,000 Medicare enrollees, and the IBD-associated surgery rate was 17.4 per 100 hospital stays. The age-adjusted hospitalization rate for ulcerative colitis was 16.2 per 100,000 Medicare enrollees, and the surgery rate was 11.2 per 100 stays. During 1999–2017, the hospitalization rate for both Crohn’s disease and ulcerative colitis decreased among non-Hispanic white (white) beneficiaries, but not among non-Hispanic black (black) beneficiaries. Health care utilization assessment is needed among black beneficiaries with IBD. Disease management for older adults with IBD could focus on increasing preventive care and preventing emergency surgeries that might result in further complications.

MedPAR data, obtained from the Centers for Medicare & Medicaid Services, contain information on 100% of Medicare beneficiaries who use hospital inpatient services and skilled nursing facilities, including information about admission, discharge, diagnosis, and procedure codes related to a hospital stay.* To estimate IBD-related hospitalization rates and hospitalization outcomes in 2017, IBD-related hospital admissions^† based on International Classification of Diseases, Tenth Edition, Clinical Modification (ICD-10-CM) principal diagnosis codes (K50 for Crohn’s disease and K51 for ulcerative colitis) were used to identify eligible beneficiaries from 50 states and the District of Columbia (DC) who were aged ≥65 years at the time of Medicare enrollment and hospital admission, were continuously enrolled in Medicare Part A, and were not enrolled in a Health Maintenance Organization in 2017. To analyze temporal trends in hospitalization rates by race/ethnicity, ICD-9-CM diagnosis codes (555 for Crohn’s disease and 556 for ulcerative colitis) were used for hospitalizations before October 1, 2015, and ICD-10-CM codes for those on or after that date. The age-adjusted hospitalization rate (hereafter referred to as hospitalization rate) was estimated per 100,000 eligible Medicare enrollees^§ for 50 states and DC and by selected demographic characteristics. The surgery rate was defined as the number of partial or total resections of the small or large intestine per 100 hospital stays.^¶ The 30-day readmission rate was calculated as the number of all-cause readmissions to acute-care, nonfederal hospitals within 30 days of the discharge date associated with the index admission, per 100 hospital stays.** The 30-day mortality rate was defined as the number of all-cause deaths that occurred within 30 days of the index admission per 100 hospital stays.^†† All hospitalization outcome rates were calculated with 95% confidence intervals by demographic variables including age group (65–74 and ≥75 years), sex, race/ethnicity (white, black, other [Hispanic, Asian/Pacific Islander, American Indian/Alaska Native, and other], or unknown)^§§ and urban or rural residence of beneficiary.^¶¶ Group differences were determined by Z-test with the significance level set at alpha = 0.05. Trends in hospitalization rates were assessed using a linear regression. All analyses were performed separately for Crohn’s disease and ulcerative colitis using SAS Enterprise Guide (version 7.1; SAS Institute).

In 2017, among approximately 30,658,000 eligible Medicare enrollees aged ≥65 years, 4,782 hospital admissions were attributable to Crohn’s disease (15.5 per 100,000 Medicare population), and 4,932 were attributable to ulcerative colitis (16.2 per 100,000 Medicare population) (Table). For both diseases, the hospitalization rate was higher among women, whites, and urban residents than among men, blacks, and rural residents. Compared with older beneficiaries (those aged ≥75 years), younger beneficiaries (those aged 65–74 years) had a higher rate of hospitalization for Crohn’s disease but a lower rate for ulcerative colitis. Overall, the surgery rate was 17.4 per 100 hospital stays for Crohn’s disease and 11.2 per 100 stays for ulcerative colitis. For both diseases, the surgery rate was lower among older beneficiaries, women, and blacks than among their counterparts. The 30-day readmission rate for ulcerative colitis was higher among older beneficiaries, and for Crohn’s disease was higher among men than women. The 30-day mortality rates for Crohn’s disease and ulcerative colitis were 2.7 and 3.8 per 100 stays, respectively. For both diseases, the 30-day mortality rate was higher among older beneficiaries. The hospitalization rate was generally higher in the Midwest for Crohn’s disease and in the Northeast for ulcerative colitis (Figure 1). In each year during 1999–2017 a modest decrease occurred in the hospitalization rate for Crohn’s disease overall (0.08 per 100,000 eligible Medicare enrollees, p = 0.002) and among whites (0.07, p = 0.01), but no significant change among blacks occurred (p = 0.11) (Figure 2). In each year during 1999–2017, the hospitalization rate for ulcerative colitis decreased overall (0.31, p<0.001) and among whites (0.32, p<0.001), with no significant change among blacks (p = 0.06).

Acknowledgment

ResDAC, Minneapolis, Minnesota.

Corresponding author: Fang Xu, fangxu@cdc.gov, 770-488-4563.

¹Division of Population Health, National Center for Chronic Disease Prevention and Health Promotion, CDC.

References

1. Nimmons D, Limdi JK. Elderly patients and inflammatory bowel disease. World J Gastrointest Pharmacol Ther 2016;7:51–65. CrossRef PubMed
2. Ananthakrishnan AN, McGinley EL, Binion DG. Inflammatory bowel disease in the elderly is associated with worse outcomes: a national study of hospitalizations. Inflamm Bowel Dis 2009;15:182–9. CrossRef PubMed
3. Malarcher CA, Wheaton AG, Liu Y, et al. Hospitalizations for Crohn’s disease—United States, 2003–2013. MMWR Morb Mortal Wkly Rep 2017;66:377–81. CrossRef PubMed
4. Benchimol EI, Kaplan GG, Otley AR, et al. Rural and urban residence during early life is associated with risk of inflammatory bowel disease: a population-based inception and birth cohort study. Am J Gastroenterol 2017;112:1412–22. CrossRef PubMed
5. Frolkis AD, Dykeman J, Negrón ME, et al. Risk of surgery for inflammatory bowel diseases has decreased over time: a systematic review and meta-analysis of population-based studies. Gastroenterology 2013;145:996–1006. CrossRef PubMed
6. Nguyen GC, Chong CA, Chong RY. National estimates of the burden of inflammatory bowel disease among racial and ethnic groups in the United States. J Crohn’s Colitis 2014;8:288–95. CrossRef PubMed
7. Nguyen GC, LaVeist TA, Harris ML, Wang MH, Datta LW, Brant SR. Racial disparities in utilization of specialist care and medications in inflammatory bowel disease. Am J Gastroenterol 2010;105:2202–8. CrossRef PubMed
8. Jeuring SF, van den Heuvel TR, Zeegers MP, et al. Epidemiology and long-term outcome of inflammatory bowel disease diagnosed at elderly age—an increasing distinct entity? Inflamm Bowel Dis 2016;22:1425–34. CrossRef PubMed
9. Hazratjee N, Agito M, Lopez R, Lashner B, Rizk MK. Hospital readmissions in patients with inflammatory bowel disease. Am J Gastroenterol 2013;108:1024–32. CrossRef PubMed
10. Farraye FA, Melmed GY, Lichtenstein GR, Kane SV. ACG clinical guideline: preventive care in inflammatory bowel disease. Am J Gastroenterol 2017;112:241–58. CrossRef PubMed

Abbreviation: CI = confidence interval.
* IBD encompasses Crohn’s disease and ulcerative colitis.
^† The number of eligible Medicare beneficiaries aged ≥65 years in 2017 in the United States was approximately 30,658,000.
^§ Hospitalizations per 100,000 Medicare enrollees, age-adjusted to the 2000 U.S. Standard Population aged ≥65 years based on two age groups (65–74 years and ≥75 years), except for age-specific analysis. https://www.cdc.gov/nchs/data/statnt/statnt20.pdf.
^¶ Per 100 hospital stays.
** The denominator is number of hospital admissions. To calculate surgery rate and geometric mean of length of stay, n = 4,782 for Crohn’s disease and n = 4,932 for ulcerative colitis.
^†† International Classification of Diseases, Tenth Edition, Procedure Coding System procedure codes involving small and large intestine include partial resection (0DB80ZZ, 0DB90ZZ, 0DBA0ZZ, 0DBB0ZZ, 0DBC0ZZ, 0DBE0ZZ, 0DBF0ZZ, 0DBG0ZZ, 0DBH0ZZ, 0DBK0ZZ, 0DBL0ZZ, 0DBM0ZZ, 0DBN0ZZ, 0DBP0ZZ, 0DB83ZZ, 0DB93ZZ, 0DBA3ZZ, 0DBB3ZZ, 0DBC3ZZ, 0DBE3ZZ, 0DBF3ZZ, 0DBG3ZZ, 0DBH3ZZ, 0DBK3ZZ, 0DBL3ZZ, 0DBM3ZZ, 0DBN3ZZ, 0DBP3ZZ, 0DB84ZZ, 0DB94ZZ, 0DBA4ZZ, 0DBB4ZZ, 0DBC4ZZ, 0DBE4ZZ, 0DBF4ZZ, 0DBG4ZZ, 0DBH4ZZ, 0DBK4ZZ, 0DBL4ZZ, 0DBM4ZZ, 0DBN4ZZ, 0DBP4ZZ, 0DB87ZZ, 0DB97ZZ, 0DBA7ZZ, 0DBB7ZZ, 0DBC7ZZ, 0DBE7ZZ, 0DBF7ZZ, 0DBG7ZZ, 0DBH7ZZ, 0DBK7ZZ, 0DBL7ZZ, 0DBM7ZZ, 0DBN7ZZ, 0DBP7ZZ, 0DB88ZZ, 0DB98ZZ, 0DBA8ZZ, 0DBB8ZZ, 0DBC8ZZ, 0DBE8ZZ, 0DBF8ZZ, 0DBG8ZZ, 0DBH8ZZ, 0DBK8ZZ, 0DBL8ZZ, 0DBM8ZZ, 0DBN8ZZ, 0DBP8ZZ) and total resection (0DT80ZZ, 0DT90ZZ, 0DTA0ZZ, 0DTB0ZZ, 0DTC0ZZ, 0DTE0ZZ, 0DTF0ZZ, 0DTG0ZZ, 0DTH0ZZ, 0DTK0ZZ, 0DTL0ZZ, 0DTM0ZZ, 0DTN0ZZ, 0DTP0ZZ, 0DT84ZZ, 0DT94ZZ, 0DTA4ZZ, 0DTB4ZZ, 0DTC4ZZ, 0DTE4ZZ, 0DTF4ZZ, 0DTG4ZZ, 0DTH4ZZ, 0DTK4ZZ, 0DTL4ZZ, 0DTM4ZZ, 0DTN4ZZ, 0DTP4ZZ, 0DT87ZZ, 0DT97ZZ, 0DTA7ZZ, 0DTB7ZZ, 0DTC7ZZ, 0DTE7ZZ, 0DTF7ZZ, 0DTG7ZZ, 0DTH7ZZ, 0DTK7ZZ, 0DTL7ZZ, 0DTM7ZZ, 0DTN7ZZ, 0DTP7ZZ, 0DT88ZZ, 0DT98ZZ, 0DTA8ZZ, 0DTB8ZZ, 0DTC8ZZ, 0DTE8ZZ, 0DTF8ZZ, 0DTG8ZZ, 0DTH8ZZ, 0DTK8ZZ, 0DTL8ZZ, 0DTM8ZZ, 0DTN8ZZ, 0DTP8ZZ).
^§§ 30-day readmission rate was calculated as the number of all-cause readmissions to acute care, nonfederal hospitals within 30 days from the discharge date associated with an index admission per 100 stays. Index admissions were nonfederal acute-care hospital admissions with Crohn’s disease or ulcerative colitis as the principal diagnosis, had a live discharge, and had a routine discharge to home or skilled nursing facility. To ensure the calculation of the complete 30-day readmission, index admissions with discharge date in December 2017 were excluded. Readmissions were defined as all-cause acute admissions whose discharge destinations were not against medical advice or expired. Multiple readmissions within the 30-day time frame from one index admission were counted as one readmission. A readmission from a previous index admission could be also counted as a new index admission if it met the selection criteria for an index admission (https://www.medicare.gov/hospitalcompare/data/30-day-measures.html). To calculate 30-day all-cause readmission rate, n = 3,022 for Crohn’s disease; n = 3,060 for ulcerative colitis.
^¶¶ 30-day mortality rate was defined as number of all-cause deaths occurred within 30 days from IBD-related admissions per 100 hospital stays. Hospitalizations were excluded if patients were discharged against medical advice. More information is available at https://www.medicare.gov/hospitalcompare/data/30-day-measures.html. To calculate 30-day all-cause readmission rate, n = 4,781 for Crohn’s disease; n = 4,932 for ulcerative colitis.
*** Geometric mean is the x^th root of the product of the length of stay (days) from x patients (x indicates the number of patients), which, because it is not influenced by outliers, is used here rather than arithmetic mean.
^††† International Classification of Diseases, Tenth Edition, Clinical Modification diagnosis codes K50 (Crohn’s disease) and K51 (ulcerative colitis).
^§§§ Data were suppressed according to the cell size suppression (https://www.resdac.org/articles/cms-cell-size-suppression-policy) or if the relative standard error was >0.3.
^¶¶¶ Other includes Hispanic, Asian, Native American, and all others.
**** Urban areas include large metro, large fringe metro, medium metro, or small metro. Rural areas include micropolitan and noncore. The definition is based on 2013 National Center for Health Statistics Urban-Rural Classification Scheme for Counties (https://www.cdc.gov/nchs/data/series/sr_02/sr02_166.pdf).

FIGURE 1. Age-adjusted hospitalization rates*^,† for Crohn’s disease or ulcerative colitis^§ as the principal diagnosis among Medicare fee-for-service beneficiaries, by state — United States, 2017

Abbreviation: DC = District of Columbia.

* Hospitalizations per 100,000 eligible Medicare enrollees, age-adjusted to the 2000 U.S. standard population aged ≥65 years (https://www.cdc.gov/nchs/data/statnt/statnt20.pdf) based on two age groups (65–74 years and ≥75 years).

^† State-level age-adjusted hospitalization rates were categorized into tertiles. Data were suppressed if relative standard errors were >0.3.

^§ Crohn’s disease and ulcerative colitis, collectively referred to as inflammatory bowel disease, are conditions characterized by chronic inflammation of the gastrointestinal tract.

FIGURE 2. Age-adjusted hospitalization rates*^,† for inflammatory bowel disease^§ as the principal diagnosis among Medicare fee-for-service beneficiaries, by race/ethnicity — United States, 1999–2017^¶

* Hospitalizations per 100,000 eligible Medicare enrollees, age adjusted to the 2000 U.S. standard population aged ≥65 years (https://www.cdc.gov/nchs/data/statnt/statnt20.pdf) based on two age groups (65–74 years and ≥75 years).

^† Linear trend p-values were assessed from a linear regression.

^§ Inflammatory bowel disease is a term for two conditions (Crohn’s disease and ulcerative colitis) that are characterized by chronic inflammation of the gastrointestinal tract.

^¶ The conversion from International Classification of Diseases, Ninth Edition diagnosis codes to the International Classification of Diseases, Tenth Edition, Clinical Modification diagnosis codes occurred on October 1, 2015.