CF patients in US living longer now, 20-year trends data show
Mortality rate significantly declined from 1999 to 2020
People with cystic fibrosis (CF) in the U.S. tend to live more than a decade longer now than patients did about 20 years ago, according to a study that found deaths from CF have about halved from 1999 to 2020.
“These changes were relatively slow during an earlier period of the study, followed by a rapid decline more recently,” researchers wrote, calling attention to the need for approaches that meet future needs in treatment and care.
CFTR modulators have led to longer, healthier lives for patients
CFTR modulators target the faulty CFTR protein that causes CF. By improving its function, they reduce thick mucus build-up, preventing lung infections and damage. They also slow disease progression, leading to longer, healthier lives for CF patients.
“Several recent studies have reported encouraging survival trends,” but studies from the U.S. drew on data only from the Cystic Fibrosis Foundation Patient Registry, which is composed of patients cared for at specialized CF centers.
To get a broader picture of CF-related mortality trends in the U.S., the researchers now drew on public health data collected from 1999 to 2020 and available from the CDC WONDER database. During this period, more than 56 million people died in the U.S.
CF accounted for 11,068 (0.02%) of those deaths. The overall age-standardized mortality rate, a weighted average that takes into account the breakdown of age groups, was 1.65 per million people.
The mortality rate varied across regions, with the highest average in the Midwest (1.82 per million people). The average was lower in counties with a population greater than 250,000 than in less populated counties (1.53 vs. 2.13 per million people).
The rapidly changing epidemiology [disease distribution] of CF presents new challenges, requiring different and more collaborative approaches to healthcare delivery to meet future needs adequately.
Median age of death increased by 13 years from 1999 to 2020
The median age of death was 24 years in 1999 and 37 years in 2020, an increase of 13 years in just over two decades. In 1999, the median age of death was higher for male versus female patients, but the difference resolved over the study period.
“The difference in the median age of death between whites and other races slightly improved over the study period, but the gap widened between non-Hispanic and Hispanic ethnicities over time,” the researchers wrote.
Differences in the proportion of patients who are ineligible for treatment with CFTR modulators — 10% in non-Hispanic versus 25% in Hispanic ethnicities — may explain the gap, they noted.
The number of deaths decreased from 539 in 1999 to 342 in 2020, which translated to a drop in the mortality rate from 1.9 to 1.04 per million people. Of the 342 deaths in 2020, six (1.7%) had COVID-19 as the underlying cause of death. (The underlying cause of death was defined as “the disease or injury which initiated the train of events leading directly to the death.”)
The researchers used joinpoint modeling to analyze trends in data by identifying points where the direction of the trend changes significantly. This helps them understand complex patterns in a concise manner.
Decline in CF mortality rate from 1999 to 2020
They found a steady decline in the mortality rate from 1999 to 2018, followed by a trend toward a more rapid drop from 2018 to 2020, both in male and female patients.
A decline was observed in whites but not in other races, and in non-Hispanic groups but not in Hispanic ethnicities. The mortality rate decreased in all regions except the West, with a decline similar in rural and urban areas.
“We observed patterns of sex, ethnic, racial, and geographical disparities associated with the worsening of the gap between ethnicities, narrowing of the gap between races and rural vs. urban counties, and closing of the gap between sexes over the study period,” the researchers wrote.
“The rapidly changing epidemiology [disease distribution] of CF presents new challenges, requiring different and more collaborative approaches to healthcare delivery to meet future needs adequately,” they concluded.