Neil Canavan
April 3, 2012 (New York, New York) — An analysis involving more than 30 million medical claims from a commercial insurance provider and from Medicare suggest that current recommendations for hepatitis C virus (HCV) testing are not being followed.
In fact, the adult demographic with the lowest incidence of HCV infection — young women — is the most likely to be tested, according to data presented here at the International Conference on Viral Hepatitis 2012.
"The CDC is looking at changing the HCV guidelines to mandate a 1-time HCV antibody test for everybody born between 1945 and 1965," said lead analyst Camilla Graham, MD, who is vice president of global medical affairs for Vertex Pharmaceuticals.
Recent studies have suggested that the 1945 to 1967 birth cohort accounts for 81% of all people diagnosed with HCV infection. "This study was done to look at who is actually getting tested for HCV in the United States under current risk-based screening recommendations."
The analysis was performed using records from the Thomson Medstat MarketScan commercial database, a resource comprising medical and outpatient pharmacy claims from employer-sponsored health insurance plans and including more than 30 million commercially insured and 3 million Medicare supplemental-insured individuals. Claims made from 2004 to 2008 were used for this study.
People who had undergone HCV testing were identified on the basis of Current Procedural Technology codes for HCV antibody or HCV RNA testing, birth cohort, and sex. People diagnosed with HCV infection after testing were identified with International Classification of Diseases, Ninth Revision (ICD-9) codes. "Filters were also employed to find people newly identified with HCV as of 2008," said Dr. Graham, "to get a sense of diagnosis trends."
For 2008, only 1.1% of individuals in the payer population and 1.7% in the Medicare population had been tested for HCV. "This is actually an increase from 2004, and a maximum for the study period," Dr. Graham noted.
"When we look at the commercial database, we see that there are more women being tested than men [62% vs 38% in 2008]," she said. The sex distribution in the Medicaid population was about even for men and women (51% vs 49%).
Although this finding seems balanced on the surface, data continue to accrue showing that men have higher exposure to HCV and a greater likelihood of having chronic HCV infection. Of the currently identified 800,000 HCV-related cases of cirrhosis in the United States, 75% are men.
Current testing practices do not reflect actual rates of HCV infection as indicated by birth cohort, Dr. Graham said. Only 32.8% of people born from 1945 to 1964 have been tested, even though this cohort has the highest rate of infection. In contrast, 48.2% of people born from 1970 to 1989 have been tested, although their rate of HCV infection is known to be much lower.
"Interestingly, in this younger group, almost twice as many women as men are being tested," she said.
An analysis of HCV diagnosis during the study period illustrates a displaced diligence in HCV screening. "When we look at the people who were actually diagnosed, young women have a much lower prevalence than older men."
For the birth period of 1945 to 1954, 3.5% of women and 7.4% of men were diagnosed with HCV. For 1955 to 1964, 2.9% of women and 5.7% of men were diagnosed with HCV.
"Medicare is a more complicated population," because some patients are enrolled on the basis of disability rather than age, said Dr. Graham. "But again, you see a shockingly high prevalence of HCV in men." Medicare data show that 16.1% of men and 10.4% of women in the 1945 to 1954 cohort and 19.1% of men and 13.3% of women in the 1955 to 1974 cohort are HCV-positive.
"Is Medicare aware of this serious HCV problem as the leading edge of the boomers are entering the program?" she wondered.
The precise reason for the tilt toward the more prevalent HCV testing of women is not known, but Dr. Graham speculated that the driver is prenatal testing.
Findings "Not a Surprise"
"I've looked at the data from my own institution," said Natalie Kil, MPH, project manager in the division of general internal medicine at Mount Sinai Hospital in New York City. "I can tell you that it is not at all common for a primary care doctor to order a routine hep C test. They're only doing it by way of known risk factors, and most clinicians, from my understanding, are not really asking about risk factors."
Through Kil's involvement in Mount Sinai's community outreach program to help identify HCV-infected individuals, she has noted no small measure of misplaced trust.
"We find that when we go out and do hep C testing, most people who are in care somewhere, who have a regular primary care doctor, think that they have already been tested. People say, 'Oh my doctor is wonderful, he tests me for everything,' but you can see from these data that this is simply not happening," Kil explained.
Dr. Graham is an employee of Vertex Pharmaceuticals. Ms. Kil has disclosed no relevant financial relationships.
International Conference on Viral Hepatitis (ICVH) 2012: Abstract 79332. Presented March 26, 2012.
