Recurrent respiratory papillomatosis (RRP) is a rare condition in children acquired around the time of delivery and is caused by HPV types 6 and 11 leading to wart-like growths in the respiratory tract resulting in hoarseness and airway obstruction. Its incidence in children is expected to decline with HPV vaccination which has been FDA-approved in the US since 2006. New York is a populous state with vaccination rates among girls typical of many states nationally, growing from percentages in the 50's to the 60's over the last decade (1). We expect changes in RRP incidence attributable to vaccination to first be evident in young children. We sought to determine whether the rate or frequency of treatments for RRP has changed since the approval of HPV vaccination.
We obtained data from NY State Ambulatory Surgery and Services Database (2) between years 2004-2013 for discharge encounters of children under the age of 18 who had ambulatory procedures with ICD-9 code corresponding to benign neoplasm of the larynx and procedure codes relating to typical RRP treatments. A visit linkage variable allowed for tracking patients who had multiple discharges in a year. All facilities licensed to perform same-day surgery in NY were included (as such, parameters rather than statistics were calculated). Unable to calculate RRP diagnosis with this source, we used treatment as a loose proxy for prevalence. Patients were placed into older (age 10-17) and younger (age <10) groups. Trends over time in number and age of patients treated per year and average number of treatments per patient per year were calculated. Rates were generated with population estimates from Vital Statistics data. Trends across pre- and post-vaccination periods were investigated through raw comparisons of these parameters by year and age group.
The average rate of treated RRP per year between 2004-2013 was 0.87/100,000 (range 0.66 to 1.09) for older children and 0.91/100,000 (range 0.60 to 1.10) for younger children. The number of treatments per year in the older group averaged 1.64 (range 1.08-2.14) and in the younger group averaged 2.14 (range 1.93-2.68). No trends in treatment prevalence, age, or treatment frequency in either group were apparent over time.
Despite growing uptakes of HPV vaccination, the rate and frequency of treatment of RRP in NY children have not changed over time. The rarity of RRP and the delay between HPV vaccination and exposure of at-risk infants may explain these results. No central source of US RRP patients exists, however this dataset could be useful for long term monitoring which will be necessary to identify any effect of HPV vaccination on rates of RRP in children.
1. Centers for Disease Control and Prevention. 2008 through 2015 Adolescent Human Papillomavirus (HPV) Vaccination Coverage Trend Report. Available at: https://www.cdc.gov/vaccines/imz-managers/coverage/teenvaxview/data-reports/hpv/trend/index.html. Accessed April 30, 2017
2. HCUP State Ambulatory Surgery and Services Databases (SASD). Healthcare Cost and Utilization Project (HCUP). 2004-2013. Agency for Healthcare Research and Quality, Rockville, MD. www.hcup-us.ahrq.gov/sasdoverview.jsp