Incidence of invasive pneumococcal disease in children with commercial insurance or Medicaid coverage in the United States before and after the introduction of 7- and 13-valent pneumococcal conjugate vaccines during 1998–2018

Table 1 Demographic characteristics of commercially insured children aged < 18 years with IPD episodes, by PCV period (1998–2018)

	Pre-PCV7	Early PCV7	Late PCV7	Early PCV13	Late PCV13
	(1998–1999)	(2001–2005)	(2006–2009)	(2011–2013)	(2014–2018)
Total number of patients^a, N	136	734	1,409	871	796
Age, mean (SD)^b,c,d	2.84 (4.00)	4.21 (5.14)	4.13 (5.14)	5.18 (5.42)	5.15 (5.38)
< 2 years, %	58.1	46.3	46.1	37.8	37.1
2–4 years, %	20.6	20.3	20.3	17.8	19.8
5–17 years, %	21.3	33.4	33.6	44.4	43.1
Male, %	52.2	53.7	54.0	58.0	54.8
Region
Northeast, %	16.2	10.2	9.4	16.9	17.1
North Central, %	30.1	21.4	22.4	23.2	21.2
South, %	41.9	44.4	48.7	35.9	41.3
West, %	4.4	22.8	18.9	20.3	19.2
Missing/unknown, %	7.4	1.2	0.6	3.7	1.1
Urbanicity
Urban, %	65.4	78.7	80.6	79.2	84.8
Rural, %	27.2	20.0	18.8	17.1	11.6
Missing, %	7.4	1.2	0.6	3.7	3.6
Health plan types
HMO/EPO, %	9.6	22.2	16.9	16.3	9.0
PPO/POS, %	52.9	68.8	74.8	68.9	65.2
HDHP/CDHP, %	0.0	2.0	2.2	6.9	19.1
FFS, %	37.5	4.9	2.1	1.0	1.8
Missing, %	0.0	2.0	4.0	6.9	4.9

Abbreviations: CDHP Consumer directed health plan, EPO Exclusive provider organization, FFS Fee-for-service, HDHP High-deductible health plan, HMO Health maintenance organization, IPD Invasive pneumococcal disease, PCV Pneumococcal conjugate vaccine, POS Point of service, PPO Preferred provider organization, SD Standard deviation
^aPatients' demographic characteristics and risk factors were first determined by each calendar year and then combined by PCV periods, assuming each year has distinct patient population
^bPatients' month and day of birth was imputed as July 1st for all patients. Age at onset was calculated as the difference between condition start date and imputed birth date. Patients with negative age at onset were included in the analysis
^cFor each calendar year, patients' demographic characteristics were determined at the index episode, which was defined as the first IPD episode in the given calendar year
^dStandard deviations for age in each vaccine period were calculated using the pooled standard deviation of the samples in relevant years

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