Volume 12, Number 10—October 2006
Research
Health Benefits, Risks, and CostEffectiveness of Influenza Vaccination of Children
Table A1
Variable  Most likely estimate  Range for sensitivity analysis  Source  Type of distribution  Distribution parameter 1  Distribution parameter 2  

Influenza illness attack rate (annual)  (1–10)  
6–23 mo  0.157  0.02–0.35  β^{1}  2.2  11.8  
2 y  0.155  0.02–0.35  Derived^{2}  
3–4 y  0.155  0.02–0.35  Derived  
5–11 y  0.08  0.01–0.18  Derived  
12–17 y  0.06  0.01–0.14  Derived  
Probability of an outpatient visit for child with influenza illness^{3}  (5,11,12)4  
6–23 mo  0.5  0.17–0.83  β  3.3  3.5  
2 y  0.47  0.15–0.81  β  3.29  3.71  
3–4 y  0.43  0.12–0.78  β  3.01  3.99  
5–11 y  0.28  0.11–0.5  β  5.6  14.4  
12–17 y  0.24  0.06–0.5  β  2.88  19.12  
Probability of otitis media for a child with medically attended influenza illness  (13–16), expert panel  
6–23 mo  0.63  0.33–0.8  β  6.3  3.7  
2 y  0.58  0.27–0.8  β  5.22  3.78  
3–4 y  0.39  0.17–0.6  β  6.24  9.76  
5–11 y  0.23  0.05–0.5  β  2.53  8.47  
12–17 y  0.15  0.01–0.4  β  1.5  8.5  
Probability of nonhospitalized pneumonia or other outpatient complication for child with medically attended influenza illness^{5}  (11,12); expert panel  
6–23 mo  0.2  0.04–0.5  β  2.6  10.4  
2 y  0.15  0.02–0.4  β  1.95  11.05  
3–4 y  0.15  0.02–0.4  β  1.95  11.05  
5–11 y  0.11  0.02–0.3  β  2.2  17.8  
12–17 y  0.08  0.01–0.2  β  2.16  24.84  
Hospitalizations for pneumonia or other respiratory conditions due to influenza per 10,000 children not at high risk^{6}  (7,11,17); W. Thompson, pers. comm.)  
6–23 mo  28.3  1.9–80.0  β  5.5  244.5  
2 y  17.1  0–56.8  β  3.4  246.6  
3–4 y  8.0  0–35.4  β  1.6  248.4  
5–11 y  3.1  0–16.0  β  7.95  1,492.1  
12–17 y  3.1  0–14.9  β  10.5  1,489.5  
Probability of longterm sequelae after influenzarelated hospitalization^{2}  0.01  0.001–0.03  Expert panel  β  1.3  11.7  
Probability of death during influenzarelated hospitalization  0.0009  0–0.002  (18)4  β  1.7  18.3  
Vaccine effectiveness in preventing influenza illness9  
IIV  0.69  0.4–0.9  (19)4  β  7.59  3.41  
LAIV  0.838  0.6–0.96  (20)4  β  16.76  3.24  
Probability of medically attended vaccinationrelated adverse events  
Injection site reaction  
6–23 mo  0.008  0.002–0.017  (8)  β  4.0  46.0  
2 y  0.003  Derived^{10}  
3–4 y  0.002  Derived  
5–11 y  0.001  Derived  
12–17 y  0.0003  Derived  
Systemic reaction (fever)11  
6–23 mo  0.013  0.001–0.025  (20)  β  5.2  194.8  
2 y  0.011  Derived  
3–4 y  0.009  Derived  
5–11 y  0.004  Derived  
12–17 y  0.003  Derived  
Anaphylaxis  0.00000025  0–0.000001  Expert panel  β^{12}  0.5  19.5  
GuillainBarré syndrome  0.000001  0–0.00001  Expert panel  Triangular  0.000001 (most likely)  0 (min), 0.000002 (max)  
Influenzarelated costs  
OTC medications^{13}  $3  (21,22); J. Finkelstein, pers. comm.; expert panel  
Physician visit for uncomplicated influenza^{14}  $27  $0–$180  Marketscan database15  Lognormal^{16}  32  27  
Physician visit for otitis media  
6–3 mo  $78  $23–$197  Marketscan database^{17}  Lognormal  98  78  
2–4 y  $83  $23–$200  Marketscan database^{17}  Lognormal  100  83  
5–17 y  $94  $31–$245  Marketscan database^{17}  Lognormal  117  94  
Physician visit for nonhospitalized pneumonia  
6–23 mo  $179  $62–$715  Marketscan database^{17}  Lognormal  252  179  
2–4 y  $88  $27–$333  Marketscan database^{17}  Lognormal  130  88  
5–17 y  $109  $34–$503  Marketscan database^{17}  Lognormal  187  109  
Hospitalization^{18}  
6–23 mo  $4,306  $1,307–$34,473  Marketscan database^{17}  Lognormal  13194  4306  
3–4 y  $4,180  $1,292–$32,030  Marketscan database^{17}  Lognormal  10000  4180  
5–17 y  $5,135  $1,373–$42,990  Marketscan database^{17}  Lognormal  14956  5135  
Longterm sequelae following influenzarelated hospitalization^{19}  $625,000  $0–$1,000,000  (23)  
Vaccination costs  
Per dose, IIV^{20} (children <3 y)  $9.56^{21}  1×–4× base case  (21)  
Per dose, IIV (children >3 y)  $6.86^{21}  1×–4× base case  (21)  
Per dose, LAIV^{20}  $12.89^{22}  $10–$25  (24,25)  
Administration (0–2 visits)^{23}  $25  $10–$40  (26)  
Parent time costs^{24}  $32  $0–$62  (27), expert panel  
Total vaccination costs  $30–$110  
6–23 mo  $79  
2 y  $66  
3–4 y  $59  
5–11 y  $49  
12–17 y  $49  
Vaccinationrelated adverse events  
Physician visit for injection site reaction^{25}  $61  $30–$683  Marketscan database^{26}  Lognormal^{16}  202  61  
Anaphylaxis^{27}  $2,699  $52–$13,754  Marketscan database^{28}  Lognormal^{16}  4527  2699  
GuillainBarré syndrome^{29}  $23,359  $6,663–$78,912  Marketscan database^{28}  Lognormal^{16}  32196  23359  
Quality adjustments^{30,31} (disutility associated with an event)  
Episode of influenza  0.005  0.002–0.009  (27)  β  7.35  1492.65  
Otitis media  0.042  0.023–0.065  (28)  β  14.56  335.44  
Nonhospitalized complications (pneumonia)  0.046  0.027–0.071  (28)  β  16.21  333.8  
Hospitalization, pneumonia  0.076  0.054–0.100  (28)  β  37.85  462.15  
Anaphylaxis  0.02  0.006–0.041  (27)  β  4.53  225.47  
GuillainBarré syndrome  0.141  0.092–0.199  (27)  β  22.53  137.47
IIV, inactivated influenza vaccine; LAIV, live, attenuated influenza vaccine; OTC, over the counter. 
IIV, inactivated influenza vaccine; LAIV, live, attenuated influenza vaccine; OTC, over the counter.
^{1}Distributions for transition probabilities were assigned using most likely values and ranges identified in the literature and/or expert panel. For these parameters, primary data were not available and beta distributions were assigned to match the values identified in the table.
^{2}Distributions for age groups other than 6–23 mo are based on the 6 to 23mo distribution multiplied by the ratio of the most likely estimates for the age group in question to children 6–23 mo (e.g., the distribution for 2 y is calculated by multiplying the distribution for 6–23 mo by 0.155/0.157).
^{3}Estimates for healthy children are shown in Table. Probabilities are estimated to be twice as high for children at high risk for influenzarelated complications.
^{4}Range for sensitivity analysis determined by expert opinion.
^{5}Estimates for healthy children shown in Table. Probabilities are estimated to be up to 5 times as high for children at high risk for influenzarelated complications. Base case estimates for children at high risk are 1.6 times as high as for healthy children.
^{6}Children at high risk are estimated to be hospitalized at 3–6 times the rate of healthy children.
^{7}Probability from distribution divided by 10.
^{8}Probability from distribution divided by 100.
^{9}Assumes vaccine is poorly matched with circulating virus 1 in 10 years (i.e., vaccine effectiveness is assumed to be 0 in years with a poor match).
^{10}Distributions for age groups other than 6–23 mo are based on the 6 to 23mo distribution multiplied by the ratio of the most likely estimates for the age group in question to children ages 6–23 mo (e.g., the distribution for 2 years is calculated by multiplying the distribution for 6–23 mo by 0.003/0.008).
^{11}Definitions and followup for incidence of fever following vaccination vary by study. Rates are 2× higher for highrisk subgroups.
^{12}Probability from distribution divided by 100,000.
^{13}Vary by age, calculated by costing out recommended dose of acetaminophen for average weight in each age group.
^{14}Only a proportion of children with influenza illness are assumed to make a physician visit. ICD9 codes: 487 and 487.0.
^{15}1993–1997 Marketscan database, The Medstat Group, Ann Arbor, MI, USA.
^{16}Lognormal distributions are approximated using the mean and median in Treeage. In this table, parameter 1 is the mean and parameter 2 is the median for each distribution.
^{17}20012003 Marketscan database, The Medstat Group, Ann Arbor, MI.
^{18}ICD9 codes: 460466, 471474, 477, 478, 480483, 490496, 506508, 510, 511, 514, 518, 519. 20012003 Marketscan database.
^{19}Includes costs of lifetime care and special education.
^{20}Assumed 2 doses will be required for children <5 years receiving their first influenza vaccination.
^{21}Vaccine dose costs are based on 2004 CDC negotiated prices. Cost for children <3 years assumes thimerosalfree vaccine is used.
^{22}Based on 2004 CDC negotiated price.
^{23}Common Procedural Terminology (CPT) codes: 99211, 90471. Physician costs for vaccine administration at existing visit is $10.37 (90471); $19.95 for vaccine administration requiring a separate visit (99211).
^{24}Each physician visit is assumed to take 2 hours of parent time valued at an average hourly wage rate of $15.54.
^{25}5 minute visit, CPT code 99211.
^{26} 2001–2003 Marketscan database.
^{27}ICD9 codes: 999.4, 995.0, 995.6x.
^{28}20012003 Marketscan database.
^{29}ICD9 code: 357.0.
^{30}Quality adjustments are included in the model as a onetime decrement in utility for each temporary health state. For example, an episode of influenza results in a onetime loss of 0.005 qualityadjusted life years (QALYs). Utility losses were calculated by dividing the discounted timetraded off by the respondent’s discounted life expectancy.
^{31}Average life span used to calculate total QALYs lost due to lifelong sequelae and death was 77.9–78.2 y, depending on child’s current age. See Table A1 References in Appendix.
The conclusions, findings, and opinions expressed by authors contributing to this journal do not necessarily reflect the official position of the U.S. Department of Health and Human Services, the Public Health Service, the Centers for Disease Control and Prevention, or the authors' affiliated institutions. Use of trade names is for identification only and does not imply endorsement by any of the groups named above.
 Page created: November 09, 2011
 Page last updated: November 09, 2011
 Page last reviewed: November 09, 2011
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