Skip to main content

Table 1 Input parameters

From: Public health and economic impact of vaccination with 7-valent pneumococcal vaccine (PCV7) in the context of the annual influenza epidemic and a severe influenza pandemic

 

Age group (years)

 

0 - <2

2 - 4

5 - 17

18 - 49

50 - 64

65+

Annual Incidence per 100,000

      

   Pneumococcal meningitis/a

9.1

1.1

2.3

0.5

1.5

1.7

   Pneumococcal bacteremia/a

174.8

35.8

3.8

12.3

22.7

58.8

   All-cause pneumonia/b

4,710

1,517

329

383

1,462

9,294

   All-cause otitis media (per person)/c

1.10

0.58

    

Case Fatality Rates

      

   Pneumococcal meningitis/d

0.05

0.05

0.04

0.13

0.21

0.27

   Pneumococcal bacteremia/d

0.01

0.01

0.02

0.08

0.12

0.16

   All-cause pneumonia/e

0.00

0.02

0.02

0.02

0.05

0.05

Proportion meningitis cases resulting in (%)

      

   Deafness/f

13.0

13.0

6.4

13.0

13.0

13.0

   Disability/f

6.7

6.7

5.2

6.7

6.7

6.7

Vaccine Effectiveness

      

   IPD

      

Efficacy/g

73.5%

67.0%

    

Indirect (herd) effect/h

46.8%

40.3%

17.5%

38.3%

17.4%

33.6%

   All-cause pneumonia

      

Efficacy/i

6.9%

6.3%

    

Indirect (herd) effect/j

17.6%

18.9%

9.0%

13.0%

9.3%

7.7%

   All-cause otitis media

      

Efficacy/i

6.4%

5.8%

    

Indirect (herd) effect/k

20.1%

19.0%

    

Costs ($) per Case of Pneumococcal Disease

      

   Meningitis/l

13,196

13,196

7,446

10,586

13,461

10,263

Deafness/m

101,975

101,387

97,679

82,278

57,428

31,733

Disability/m

526,174

523,143

504,006

424,543

296,317

163,738

   Bacteremia/l

2,754

2,754

7,446

10,586

13,461

10,263

   Pneumonia/n

592

592

5,166

6,465

7,558

7,263

   Otitis media/o

256

256

    
  1. Indirect (herd) effect refers to percent reduction in disease incidence in the unvaccinated
  2. IPD = invasive pneumococcal disease
  3. a. Incidence of pneumococcal meningitis and bacteremia were estimated from the published ABCs report [15]. The ABCs reports incidence for 18-34 and 35-49 year old persons separately; we combined these age groups using weighted averages based on census data.
  4. b. Incidence rates for all-cause pneumonia were adapted from Ray et al., which used unpublished Kaiser Permanente data to estimate incidence in unvaccinated populations [21, 26].
  5. c. Incidence of AOM adapted from Ray et al., combining simple and complex AOM. Only children <5 years were assumed to be at risk for AOM [21].
  6. d. Case-fatality rates for IPD were estimated from the published ABCs report [14, 15] and Robinson et al. [33]; we divided the incidence reported in the ABCs by the age-specific mortality reported by Robinson et al.
  7. e. Case-fatality rates for pneumonia were estimated from a study of community-acquired pneumonia [31]. It was assumed that there was no risk of death from AOM.
  8. f. The probabilities of deafness and disability due to meningitis were adapted from data in children and adolescents with bacterial meningitis [22, 27–29].
  9. g. Adapted from the NCKP trial of PCV7 [23]; 94% (intent-to-treat) efficacy against covered serotypes, with PCV7 coverage of approximately 80% against S.pneumoniae serotypes that cause pneumococcal meningitis and bacteremia.
  10. h. In children <5 estimated as the difference between observed changes in disease incidence from the (ABCs) Report and direct vaccine efficacy from the NCKP trial, assuming all changes in incidence not attributable to vaccine efficacy were attributable to indirect (herd) effects [14, 15, 23]; in adults estimated based changes in incidence reported in the ABCs report.
  11. i. Based on intent-to-treat data from the NCKP trial for PCV7 [23].
  12. j. In children < 5, estimated from assuming overall effectiveness is the midpoint between the NCKP trial data, which reported vaccine efficacy of 6.9% in all-cause pneumonia [26] and ecologic data reported by Grijalva (39% reduction) [18] and assuming all reductions in disease not attributable to vaccine efficacy are attributable to indirect (herd) effects. We chose the midpoint because it is not known what proportion of the reduction in admissions reported by Grijalva were due to the direct effects of PCV7 versus indirect (herd) effects within the vaccine-eligible population, and these ecological data reflect changes in hospital admissions for pneumonia rather than incidence; final estimates of indirect (herd) effects against pneumonia were similar in magnitude to the reduction in x-ray confirmed pneumonia from the trial [33, 34]. In adults, indirect (herd) effects against pneumonia were estimated from ecologic data reported by Grijalva et al. [18].
  13. k. Efficacy against AOM was calculated in a manner similar to that of pneumonia; we used the midpoint between the NCKP trial estimate (6.4%) [23] and results from a study that examined changes in AOM-related outpatient visits before and after the introduction of PCV7 (42.7% reduction) [32]; our assumption of the estimated proportion of the reduction in AOM cases that is biologically plausible to be attributable to PCV7 was based on expert opinion (personal communication with Keith Klugman, MD, PHD, Steve Pelton, MD, and Michael E. Pichichero, MD).
  14. l. The cost of diagnosing and treating meningitis and bacteremia, were derived from Ray et al. [21, 22]. Because this study did not report costs of meningitis and bacteremia separately for persons >5 years of age, we assigned the reported cost to both meningitis and bacteremia in these age groups.
  15. m. Costs of long-term consequences of meningitis were adapted from lifetime costs of deafness and disability for children <5 years [21]. To calculate the lifetime costs in persons aged >5 years, we multiplied the costs for children <5 years by the proportional difference in discounted life-expectancy as estimated from US life-tables [45].
  16. n. We combined costs of hospitalized pneumonia for persons >5 years of age [21] and non-hospitalized community-acquired pneumonia [45] to calculate the overall cost of all-cause pneumonia, assuming hospitalization rates of 12% for those aged 5 to 17 years, 28% for 18- to 49-year-olds, 25% for those aged >50 [18, 21, 47].
  17. o. We assumed that 7% of AOM cases are complex and 1.4% of cases required tympanostomy tube placement [22], and estimated the cost of simple AOM as $192, complex AOM as $557, and tympanostomy tube placement as $2,687 [21]. The reported cost is a weighted average of simple and complex AOM and cases requiring tube placement.
Back to article page

BMC Infectious Diseases

ISSN: 1471-2334

Contact us