Patients with childhood-onset IBD have increased mortality rate

Last Updated: 2018-11-15

By Scott Baltic

NEW YORK (Reuters Health) - Children diagnosed with inflammatory bowel disease (IBD) have a three-fold increase in mortality compared with the general population when followed through adulthood, a large Swedish study has found.

Although the highest risk was seen in patients with childhood-onset ulcerative colitis (UC), children diagnosed with Crohn's disease and IBD-unclassified also were at elevated risk of death.

Researchers say the mortality increase appeared not to diminish over time, even with the introduction of new drugs for treating IBD, such as immunomodulators and biologics.

"I think it is crucial for colleagues giving advice to patients and families not to be too alarmist," said Dr. Ola Olen of the Karolinska Institute and Stockholm South General Hospital. "The reader has to remember that we're talking small differences in the absolute number of deaths, and that most patients will not die from IBD and that deaths in childhood are extremely uncommon."

"That said," he told Reuters Health by email, "it seems as if childhood-onset IBD carries an extra burden (more inflammation, more active disease and for longer duration), and that we who care for these patients should probably be extra cautious in controlling the inflammation."

The findings were published online October 17 in Gastroenterology. The authors said it is the largest to date to investigate mortality in childhood-onset IBD.

The population-based cohort study drew data from a Swedish national database. Childhood-onset IBD was documented by at least two healthcare visits listing an IBD diagnosis, the first one before the individual turned 18. Each such patient was matched for age, sex, calendar year, and place of residence with up to 10 reference individuals from a national population registry.

Over a 50-year span, the researchers identified 9,442 patients with childhood-onset IBD: 4,671 with UC, 3,780 with Crohn's disease and 991 with IBD-unclassified. The cohort was 45% female, and the mean age at first diagnosis was 14.

On average, patients were followed until age 30; more than 60% of them were followed for 10 or more years, for a total of 138,690 person-years of follow-up.

There were 294 deaths (2.1/1,000 person-years) among the IBD patients versus 940 deaths controls (0.7/1,000 person-years), yielding an adjusted hazard ratio of 3.2 (95% confidence interval, 2.8 to 3.7).

When follow-up was ended at age 18, the rates were 0.9/1,000 person-years and 0.2/1,000 person-years, respectively.

Patients with childhood-onset IBD followed through adulthood (maximum age, 68 years) had an increased risk of death, regardless of the calendar period of first IBD diagnosis. And those with a first diagnosis before age 6 had higher HRs for death than children with later IBD onset.

Apart from patients with very early onset IBD, the highest relative risks were seen in UC patients with concomitant primary sclerosing cholangitis (HR, 12.2). In addition, UC patients undergoing bowel surgery (HR, 4.6) or having a first-degree relative with UC (HR, 8.3) were at a higher risk of death.

Of the deaths among the IBD patients, 133 were due to cancer (HR, 6.6), and the highest HRs were seen for diseases of the digestive system (n=54, HR 36.8).

Dr. D. Brent Polk, chair of the Crohn's & Colitis Foundation's National Scientific Advisory Committee in the U.S., who was not involved in the study, told Reuters Health by email that he considers this is "an important study" with multiple new observations.

"The clinically actionable take-aways are that children with IBD should be followed closely for disease activity and monitored for malignancy," said Dr. Polk, also at the Keck School of Medicine of USC in Los Angeles.

Because children with UC and primary sclerosing cholangitis had the highest risk of mortality, although they represented only 23 of the total 294 deaths, "this would be a sub-population of patients warranting close observation," he concluded.

SOURCE: https://bit.ly/2qMmRmn

Gastroenterology 2018.