Decline in varicella-related ambulatory visits and hospitalizations in the United States since routine immunization against varicella

Pediatr Infect Dis J. 2010 Mar;29(3):199-204. doi: 10.1097/INF.0b013e3181bbf2a0.

Abstract

Background: Widespread varicella vaccination has led to substantial decreases in varicella-related mortality and hospitalizations. The effect of the vaccine on ambulatory care utilization is poorly defined.

Objective: To determine trends in varicella-related ambulatory care and hospital discharges before and after vaccine licensure.

Design, setting, and participants: Estimates of varicella-related ambulatory and hospital discharges were calculated for the pre- (1993-1995) and post- (1996-2004) vaccine licensure periods using the National Ambulatory Medical Care Survey, National Hospital Ambulatory Medical Care Survey, and National Hospital Discharge Survey.

Main outcome measure: Ambulatory and hospital discharge rates for varicella.

Results: The rate of varicella-related ambulatory discharges decreased by 66% from 106.6 per 100,000 (95% confidence interval [CI]: 80.5-132.6) in the prelicensure period to 36.4 per 100,000 population (95% CI: 29.3-43.5) in the post-licensure period (P < 0.001). The decrease was significant across all age groups <45 years, with the greatest reduction (98%) occurring among patients 0 to 4 years of age. The incidence of varicella-related hospital discharges decreased by 53% from 30.9 per 100,000 (95% CI: 24.4-37.3) to 14.5 per 100,000 population (95% CI: 12.1-16.8; P < 0.001). This difference was significant among patients <14 years of age. Rates of varicella-related ambulatory discharges decreased significantly for both whites and non-whites in the postlicensure period, but postlicensure ambulatory discharge rates remained higher for non-whites than for whites. Decreases in varicella-related hospital discharges were statistically significant for whites and non-whites. Racial differences in the incidence of varicella-related hospital discharges also persisted following vaccine licensure.

Conclusions: Varicella-related ambulatory visits and hospitalizations have decreased significantly in the period after licensure of the varicella vaccine.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Ambulatory Care / statistics & numerical data
  • Ambulatory Care / trends*
  • Animals
  • Chickenpox / epidemiology*
  • Chickenpox Vaccine / administration & dosage
  • Chickenpox Vaccine / immunology*
  • Child
  • Child, Preschool
  • Female
  • Hospitalization / statistics & numerical data
  • Hospitalization / trends*
  • Humans
  • Infant
  • Infant, Newborn
  • Male
  • Middle Aged
  • United States / epidemiology
  • Young Adult

Substances

  • Chickenpox Vaccine