FROM CLINICAL MEDICINE & RESEARCH
The incidence of primary biliary cholangitis (PBC) in rural parts of the midwestern United States has remained stable over the last 2 decades, allowing better prognosis and improved survival rates.
In a population-based cohort study, Rajan Kanth, MD, and his associates researched 79 incident PBC cases observed in the Marshfield Epidemiologic Study Area (MESA) of 24 zip codes in central and northern Wisconsin between 1992 and 2011. The overall age- and sex-standardized PBC incidence rate was 4.9 cases per 100,000 person-years. The annual incidence rate of PBC increased; however, it was not significant (P = .114) during the 20-year study time frame. In women, PBC ranged from a low of 6.9 cases per 100,000 person-years in 1992-1996 to a high of 11.3 cases per 100,000 person-years in 2002-2006. The sex-specific comparisons were not significant at any time during the 5-year period.
After a mean follow-up of 7.3 years, 23 (29%) patients with PBC died. The estimated 10-year survival of PBC cases in MESA was 76%.
Researchers noted the MESA source population grew over the 20-year study time frame, going from a low of 364,722 MESA person-years in 1992-1996 to a high of 409,670 person-years in 2007-2011. The proportion of men and women in MESA were consistent throughout the study, but there was a general population aging trend with a 29% increase in the number of individuals aged 40-69 years in 2007-2011 relative to 1992-1996.
“The overall incidence of PBC in a Midwestern population of the United States has remained relatively stable over the last two decades,” researchers concluded. “Results suggest that the overall incidence of PBC in the United States is not rising quickly, and that patients with PBC have generally improved prognosis and survival.”
Find the full study in Clinical Medicine & Research (2017. doi: 10.3121/cmr.2017.1351 ).