About 329,000 cases of Lyme disease occur annually in the United States, according to a retrospective analysis of medical claims data.
“Our findings underscore that [Lyme disease (LD)] is a considerable public health problem, both in terms of number of cases and overall health care use,”Christina A. Nelson, MD, MPH, of the CDC in Fort Collins, Colorado, and colleagues wrote in Emerging Infectious Diseases. “Furthermore, as with other conditions, underreporting in the national surveillance system remains a challenge. Continued research and education are necessary to enhance prevention efforts and improve diagnostic accuracy to reduce the effects of this disease.”
In a retrospective analysis, Nelson and colleagues assessed data from the Truven Health MarketScan Commercial Claims and Encounters Database from 2005 to 2010. The database contains claims information for a median of 27 million people, aged 0 to 64 years, with employer-provided health insurance. The study dataset included more than 103 million person-years of observation; the median age of the population was 37 years, and 51.9% were women.
From 2005 to 2010, there were 45,430 clinician-diagnosed cases of LD; 985 were inpatient diagnoses, and 44,445 were outpatient diagnoses. Average annual incidence was 44.8 diagnoses in 100,000 people, which peaked in 2009 at 56.3 events per 100,000.
After extrapolating their data to include the entire U.S. population and correcting for coding omissions, Nelson and colleagues estimated that 329,000 cases of LD occurred each year from 2005 to 2010.
Outpatient diagnoses were greatest among boys aged 5 to 9 years and all people aged 60 to 64 years. Unexpectedly, the incidence of LD was higher in women aged 15 to 44 years, compared with surveillance data, which the authors attributed to several factors, including differential overdiagnosis of LD, insurance coverage variations and health care seeking behaviors.
“Our study highlights the need for continued coding research, particularly as health departments explore the feasibility of using electronic medical records to facilitate LD reporting,” the investigators wrote. “Additional information about LD coding practices will enable robust comparisons of ICD codes related to actual cases and facilitate future research using medical databases.”– by Colleen Owens
Disclosure: The researchers report no relevant financial disclosures.