Pediatric Septic Arthritis and Osteomyelitis in the USA: A National KID Database Analysis.

Background: Prior reports suggest that osteoarticular infections may be increasing over time.

Questions/purposes: We sought to determine if incidence rates, median in-hospital costs, and length of stay (LOS) of osteomyelitis, septic arthritis (SA), and combined infections have changed over time for pediatric patients, and how they compare to previously reported rates.

Methods: The Kids' Inpatient Database (KID), a US national sample of pediatric hospital discharge records from 1997, 2000, 2003, 2006, 2009, and 2012, was used to determine yearly estimated counts of infections in children 20 years of age or younger. US census data was used to calculate yearly incidence rates. Trend tests using linear contrast analysis were used to compare estimated median LOS and inflation-adjusted median costs over time for each type of infection.

Results: From 1997 through 2012, the incidence rate of osteomyelitis increased from 7.9 to 10.5 per 100,000, SA was unchanged from 5.3 to 5.2 per 100, and combined infections increased from 0.8 to 1.3 per 100,000. Median LOS from 1997 to 2012 showed no significant change for osteomyelitis (5.0 to 4.9 days), SA (4.4 to 4.1 days), or combined infections (6.5 to 6.8 days). Median in-hospital costs from 1997 to 2012 increased for osteomyelitis ($7735 to $11,823), SA ($5041 to $10,574), and combined infections ($12,691 to $16,260).

Conclusion: In pediatric patients, the estimated incidence rate of SA appeared stable, while rates of osteomyelitis and combined infections increased. These estimated rates fall within previously reported ranges. Despite stable LOS, costs have increased over time.