How do physician-scientists select research projects? Sometimes, they're prompted by the niggling feeling that something is not right.
That's what happened to cystic fibrosis doctor MyMy Buu, MD, the lead author on a new paper that uncovers an important health disparity, a higher mortality rate for CF patients of Hispanic ethnicity. Buu, a pediatric pulmonologist who takes care of CF kids at Lucile Packard Children's Hospital Stanford, launched the research because she noticed something worrying: It seemed to her that a lot of Hispanic children with CF were not doing well.
"...I didn't know if this was just because we have more Hispanic patients in California, or if they were actually, really, sicker," Buu said. CF is a genetic disease that causes serious breathing and digestive problems; Buu's job is a mixture of trying to help her patients stay relatively healthy and dealing with complications of the disease.
"Because I'm interested in health disparities, I wanted to see if there were any differences in outcomes in the Hispanic group," she said.
She turned to the Cystic Fibrosis Foundation's patient registry, focusing on 20 years of data that encompass every California child diagnosed with CF from the beginning of 1991 to the end of 2010. Of the children studied, Hispanic CF patients were almost three times as likely to die as their non-Hispanic counterparts.
Buu and her colleagues were able to use the data to eliminate several possible explanations for the disparity. Hispanic children were not being diagnosed later than non-Hispanic kids and did not have less access to health care, for instance. Our press release about the study describes the factors that may contribute to the disparity:
However, the researchers did find important clinical and social differences between the groups. At age 6, the earliest that lung function is routinely and reliably measured for patients with CF, Hispanic children with CF had worse lung function than non-Hispanic kids with the disease. The gap in lung function persisted as the children aged, although it did not widen. And although the same proportion of patients in both groups eventually developed CF complications, the complications struck Hispanic patients earlier in life. Hispanic patients lived in poorer neighborhoods and were more likely to be covered by public health insurance than their non-Hispanic counterparts.
The research also showed that, between the two groups, different mutations prevailed in the disease-causing gene, which is called the CF transmembrane conductance regulator gene. Hispanic patients tended to have rare and poorly characterized mutations in their CFTR gene, whereas non-Hispanic patients had more common mutations that have been more extensively researched.
The next steps, Buu said, are to make others aware of the increased risk for Hispanic CF patients and to figure out how the risk can be reduced.
Previously: Cystic fibrosis patient on her 20+ years of care, New Stanford-developed sweat test may aid in development of cystic fibrosis treatments and Film about twin sisters' double lung transplants and battle against cystic fibrosis available online
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