Introduction
Methods
Model structure
Input data
Epidemiological data
Input factor | Source/assumption |
---|---|
Population | Statistical Office of Saxony |
Vaccination coverage | |
RV cases, vaccine scenario (2007–2010) | AOK PLUS data set [19] |
RV cases, base case scenario (2007–2010) | AOK PLUS cases from 2007 counted back to 2005, then calculation of hypothetical cases (2007–2010) using average RKI growth rates (2001–2007) |
Percentage annual increase in RV cases (2001–2007) | RKI data set [26] |
Direct medical costs | AOK PLUS [19] |
Direct non-medical costs (sickness-benefits) | |
Rate of employment of mothers | Statistical Office of Saxony [36] |
Wage | Statistical Office of Saxony [27] |
Days of absence from work | Giaquinto et al. [2] |
Costs of vaccination | LAUER-TAXE® [29] |
Costs
Direct medical costs
Year | 2007 | 2008 | 2009 | 2010 | ||||
---|---|---|---|---|---|---|---|---|
Treatment group | Inpatient | Outpatient | Inpatient | Outpatient | Inpatient | Outpatient | Inpatient | Outpatient |
Age group | ||||||||
Direct medical costs | ||||||||
0–1 years | 1,737 | 85 | 1,758 | 64 | 1,813 | 73 | 1,849 | 76 |
1–2 years | 1,429 | 66 | 1,593 | 49 | 1,623 | 53 | 1,712 | 56 |
2–3 years | 1,409 | 55 | 1,555 | 45 | 1,621 | 50 | 1,680 | 52 |
3–4 years | 1,304 | 48 | 1,468 | 42 | 1,471 | 48 | 1,463 | 50 |
4–5 years | 1,294 | 46 | 1,409 | 44 | 1,441 | 48 | 1,461 | 49 |
Average BS | 1,508 | 60 | 1,614 | 48 | 1,652 | 53 | 1,700 | 55 |
Average VS | 1,517 | 61 | 1,618 | 48 | 1,656 | 53 | 1,707 | 55 |
Direct non-medical costs (sickness benefits, kinderkrankengeld) | ||||||||
0–1 years | 153 | 126 | 156 | 129 | 159 | 132 | 162 | 134 |
1–2 years | 152 | 126 | 155 | 128 | 158 | 131 | 161 | 133 |
2–3 years | 163 | 135 | 166 | 138 | 170 | 141 | 173 | 143 |
3–4 years | 173 | 144 | 177 | 146 | 180 | 149 | 184 | 152 |
4–5 years | 175 | 145 | 179 | 148 | 183 | 151 | 186 | 154 |
Costs of vaccination | 124 | 124 | 124 | 124 |
Direct non-medical costs (sickness benefit)
Age of the child (years) | Employment rate of mothers (%) | Full-time (%) | Part-time (%) |
---|---|---|---|
0–1 | 52.7 | 77 | 23 |
1–2 | 54.5 | 64 | 36 |
2–3 | 59.6 | 60 | 40 |
3–4 | 31.5 | 59 | 41 |
4–5 | 65.4 | 58 | 42 |
Vaccine scenario
Insured children | Number of RVGE cases | |||
---|---|---|---|---|
Age group/year (n) | 2007 | 2008 | 2009 | 2010 |
0–1 years | 19,094 | 19,044 | 18,093 | 17,970 |
1–2 years | 18,759 | 19,094 | 19,044 | 18,093 |
2–3 years | 18,240 | 18,759 | 19,094 | 19,044 |
3–4 years | 17,776 | 18,240 | 18,759 | 19,094 |
4–5 years | 16,484 | 17,776 | 18,240 | 18,759 |
Overall | 90,353 | 92,913 | 93,230 | 92,960 |
Vaccination coverage (%) | 2007 | 2008 | 2009 | 2010 |
---|---|---|---|---|
5 | 35 | 52 | 61 |
Unprotected children (n) | 2007 | 2008 | 2009 | 2010 |
---|---|---|---|---|
0–1 years | 18,330 | 13,712 | 10,566 | 9,201 |
1–2 years | 18,759 | 18,139 | 12,379 | 8,685 |
2–3 years | 18,240 | 18,759 | 18,903 | 17,711 |
3–4 years | 17,776 | 18,240 | 18,759 | 19,094 |
4–5 years | 16,484 | 17,776 | 18,240 | 18,759 |
Overall | 89,589 | 86,626 | 78,847 | 73,449 |
Vaccinated children (n) | 2007 | 2008 | 2009 | 2010 |
---|---|---|---|---|
955 | 6,665 | 9,408 | 10,962 |
RV cases (A08.0, A08.3, A08.4, A09) (calculated incidence rates) | |||||||||
---|---|---|---|---|---|---|---|---|---|
Year | 2007 | 2008 | 2009 | 2010 | |||||
Age/treatment group | Inpatient | Outpatient | Inpatient | Outpatient | Inpatient | Outpatient | Inpatient | Outpatient | |
0–1 years | 858 (0.05) | 4,767 (0.26) | 782 (0.06) | 4,395 (0.32) | 582 (0.06) | 3,548 (0.34) | 578 (0.06) | 3,078 (0.33) | |
1–2 years | 744 (0.04) | 9,197 (0.49) | 749 (0.04) | 9,267 (0.51) | 622 (0.05) | 8,692 (0.70) | 591 (0.07) | 6,624 (0.76) | |
2–3 years | 380 (0.02) | 7,177 (0.39) | 399 (0.02) | 7,015 (0.37) | 315 (0.02) | 6,477 (0.34) | 314 (0.02) | 5,778 (0.33) | |
3–4 years | 229 (0.01) | 5,214 (0.29) | 221 (0.01) | 5,664 (0.31) | 183 (0.01) | 4,956 (0.26) | 186 (0.01) | 4,793 (0.25) | |
4–5 years | 147 (0.01) | 3,560 (0.22) | 159 (0.01) | 4,215 (0.24) | 122 (0.01) | 3,489 (0.19) | 125 (0.01) | 3,547 (0.19) | |
Overall | 2,358 (0.03) | 29,916 (0.33) | 2,310 (0.03) | 30,556 (0.35) | 1,824 (0.02) | 27,162 (0.34) | 1,794 (0.02) | 23,820 (0.32) |
Base case scenario
Number of cases | ||||||||
---|---|---|---|---|---|---|---|---|
Age group/year | 2001 | 2002 | 2003 | 2004 | 2005 | 2006 | 2007 | 2008 |
0–1 years | 1,051 | 1,682 | 1,877 | 1,383 | 1,941 | 2,096 | 1,794 | 1,485 |
1–2 years | 2,085 | 1,989 | 1,924 | 1,445 | 2,352 | 2,508 | 2,172 | 2,256 |
2–3 years | 1,183 | 1,065 | 968 | 643 | 1,064 | 1,262 | 1,072 | 1,278 |
3–4 years | 632 | 639 | 530 | 346 | 594 | 615 | 541 | 723 |
4–5 years | 391 | 383 | 260 | 216 | 424 | 374 | 318 | 443 |
Overall | 5,342 | 5,758 | 5,559 | 4,033 | 6,375 | 6,855 | 5,897 | 6,185 |
Step 1: moving average = adjusted RKI cases per year | 2005 | 2006 | 2007 |
---|---|---|---|
2001–2005 | 2002–2006 | 2003–2007 | |
0–1 years | 1,587 | 1,796 | 1,818 |
1–2 years | 1,959 | 2,044 | 2,080 |
2–3 years | 985 | 1,000 | 1,002 |
3–4 years | 548 | 545 | 525 |
4–5 years | 335 | 331 | 318 |
Overall | 5,413 | 5,716 | 5,744 |
Step 2: % annual increase in RV cases | |||
---|---|---|---|
0–1 years | +0.13 | +0.00 | |
1–2 years | +0.04 | +0.01 | |
2–3 years | +0.00 | +0.00 | |
3–4 years | −0.02 | −0.05 | |
4–5 years | −0.03 | −0.06 | |
Average | +0.04 | +0.00 |
Step 3: counted-back AOK PLUS cases | 2005 | 2006 | 2007 |
---|---|---|---|
0–1 years | 4,688 (in. = 703, out. = 3,985) | 5,281 | 5,625 |
1–2 years | 9,139 (in. = 640, out. = 8,500) | 9,392 | 9,941 |
2–3 years | 7,313 (in. = 366, out. = 6,947) | 7,554 | 7,557 |
3–4 years | 5,756 (in. = 230, out. = 5,525) | 5,690 | 5,443 |
4–5 years | 4,299 (in. = 172, out. = 4,127) | 4,142 | 3,707 |
Overall | 30,474 | 31,995 | 32,274 |
Step 4: incidence rates | Inpatient | Outpatient | |
---|---|---|---|
0–1 years | 0.04 | 0.22 | |
1–2 years | 0.04 | 0.47 | |
2–3 years | 0.02 | 0.39 | |
3–4 years | 0.01 | 0.32 | |
4–5 years | 0.01 | 0.24 | |
Average | 0.02 | 0.33 |
-
To account for the seasonal fluctuation of RV cases within the RKI data set we calculated a moving average with a timespan of 5 years to derive adjusted case values for the years 2005, 2006 and 2007.
-
We computed the growth rates of RV cases for the years 2006 and 2007.
-
The actual numbers of RV cases from AOK PLUS from 2007 were counted back to 2005 by using the previously calculated percentage increase of the RKI cases. We assumed a constant distribution of inpatient and outpatient cases (as observed in the AOK PLUS data set for 2007–2010), following which we estimated the number of cases in both the groups—inpatient and outpatient for the year 2005.
-
The simulated numbers of RV cases were considered to infer the incidence rates of RV cases for Saxony in 2005 for the inpatient and outpatient groups based on the total number of insured children per age group. We assume those to be constant and therefore also valid for 2007 to 2010.
Year | 2007 | 2008 | 2009 | 2010 | ||||
---|---|---|---|---|---|---|---|---|
Age/treatment group | Inpatient | Outpatient | Inpatient | Outpatient | Inpatient | Outpatient | Inpatient | Outpatient |
0–1 years | 1,329 | 7,532 | 1,351 | 7,656 | 1,337 | 7,576 | 1,331 | 7,544 |
1–2 years | 1,140 | 15,145 | 1,187 | 15,772 | 1,208 | 16,050 | 1,203 | 15,982 |
2–3 years | 673 | 12,792 | 672 | 12,761 | 700 | 13,293 | 697 | 13,237 |
3–4 years | 438 | 10,515 | 429 | 10,294 | 429 | 10,301 | 427 | 10,257 |
4–5 years | 315 | 7,569 | 326 | 7,819 | 319 | 7,662 | 318 | 7,629 |
Overall | 3,962 | 53,911 | 3,974 | 54,558 | 3,946 | 54,990 | 3,888 | 54,450 |
Analyses
Base case versus vaccine scenario
Calculation of vaccination effectiveness
Herd effect and direct effect
-
Calculation of RV incidence (BS) × unprotected people (VS) as the hypothetical number of RV cases if the incidence rate were unaffected by vaccination.
-
Calculation of RV incidence (BS) × unprotected people (VS)—actual RV cases (VS) as difference between the previously calculated hypothetical cases and the actual cases taken from the VS.
Sensitivity analyses
Results
Base case scenario versus vaccine scenario
Year | Category | Avoided cases = total effect | Due to herd effect | Due to direct effect | ||
---|---|---|---|---|---|---|
Age group | Inpatient | Outpatient | Inpatient | Outpatient | ||
2007 | 0–1 years | 0 (−5.7) | 0 (−27.2) | – | – | – |
1–2 years | 0 (−4.6) | 0 (−24.5) | – | – | – | |
2–3 years | 0 (−0.2) | 0 (−0.9) | – | – | – | |
3–4 years | 0.3 | 24.1 | 0.3 | 24.1 | 0 | |
4–5 years | 0.9 | 20.7 | 0.9 | 20.7 | 0 | |
2008 | 0–1 years | 0 (−1.8) | 0 (−8.3) | – | – | – |
1–2 years | 0 (−4.2) | 0 (−19.5) | – | – | – | |
2–3 years | 0 (−0.6) | 18.7 | 0 | 18.7 | 0 | |
3–4 years | 1.1 | 6.9 | 1.1 | 6.9 | 0 | |
4–5 years | 0.9 | 0 (−0.4) | 0.9 | 0 | 0 | |
2009 | 0–1 years | 7.1 | 26.4 | 0 | 0 | 33.5 |
1–2 years | 2.4 | 9.4 | 0 | 0 | 11.8 | |
2–3 years | 4.2 | 53.4 | 4.0 | 49.4 | 4.1 | |
3–4 years | 3.5 | 53.2 | 3.5 | 53.2 | 0 | |
4–5 years | 3.2 | 45.4 | 3.2 | 45.4 | 0 | |
2010 | 0–1 years | 7.1 | 51.2 | 0 | 0 | 58.3 |
1–2 years | 2.4 | 99.7 | 0 | 0 | 102.1 | |
2–3 years | 4.2 | 89.2 | 2.7 | 61.7 | 29.0 | |
3–4 years | 3.5 | 66.4 | 3.5 | 66.4 | 0 | |
4–5 years | 3.2 | 47.6 | 3.2 | 47.6 | 0 | |
2007–2010 | 44 | 612.3 | 23.3 | 394.1 | 238.8 |
Year | 2007 | 2008 | 2009 | 2010 | 2007–2010 |
---|---|---|---|---|---|
Overall | |||||
Base case scenario | 104,058 | 103,030 | 106,275 | 108,412 | 421,776 |
Inpatient | 40,232 | 42,441 | 42,888 | 43,644 | 169,206 |
Outpatient | 63,826 | 60,589 | 63,387 | 64,768 | 252,570 |
Vaccine scenario | 102,074 | 101,452 | 91,638 | 86,926 | 382,090 |
Inpatient | 39,880 | 41,804 | 35,609 | 36,183 | 153,476 |
Outpatient | 62,195 | 59,647 | 56,029 | 50,743 | 228,614 |
Gross cost savings | 1,984 | 1,579 | 14,637 | 21,486 | 39,686 |
Inpatient | 353 | 637 | 7,279 | 7,461 | 15,730 |
Outpatient | 1,631 | 942 | 7,358 | 14,025 | 23,956 |
Costs of vaccination | 1,306 | 8,864 | 12,469 | 14,570 | 37,209 |
Net cost savings | 678 | −7,285 | 2,168 | 6,916 | 2,477 |
Gross cost savings per avoided case | 304 | ||||
Effective costs per vaccination | 285 | ||||
Net cost savings per avoided case | 19 | ||||
Cost savings due to direct and herd effects | |||||
Gross cost savings | 1,984 | 1,579 | 14,637 | 21,486 | 39,686 |
Herd effect | 1,984 | 1,579 | 9,417 | 10,458 | 23,438 |
Inpatient | 353 | 637 | 3,614 | 3,278 | 7,881 |
Outpatient | 1,631 | 942 | 5,803 | 7,181 | 15,557 |
Direct effect | 0 | 0 | 5,220 | 11,028 | 16,248 |
Vaccine impact due to direct and herd effects
Sensitivity analysis
Variation | −0.06 % | −0.04 % | −0.02 % | Base case | +0.02 % | +0.04 % | +0.06 % |
---|---|---|---|---|---|---|---|
Inpatient group | |||||||
Gross cost savings (in Euros) per 1,000 children | 36,909 | 37,802 | 38,736 | 39,686 | 40,646 | 41,660 | 42,674 |
Herd effect | 21,580 | 22,166 | 22,794 | 23,438 | 24,092 | 24,800 | 25,508 |
Direct effect | 15,330 | 15,636 | 15,942 | 16,248 | 16,554 | 16,860 | 17,166 |
Net cost savings per avoided case (Euros) | −2 | 5 | 12 | 19 | 26 | 34 | 41 |
Variation | −0.5 % | −0.4 % | −0.3 % | Base case | +0.3 % | +0.4 % | +0.5 % |
---|---|---|---|---|---|---|---|
Outpatient group | |||||||
Gross cost savings (in Euros) per 1,000 children | 36,981 | 37,522 | 38,063 | 39,686 | 41,485 | 42,102 | 42,718 |
Herd effect | 21,522 | 21,905 | 22,288 | 23,438 | 24,764 | 25,223 | 25,681 |
Direct effect | 15,459 | 15,617 | 15,775 | 16,248 | 16,721 | 16,879 | 17,036 |
Net cost savings per avoided case (Euros) | −2 | 3 | 7 | 19 | 30 | 34 | 38 |
Variation | −1 day | −0.5 days | Base case | +0.5 days | +1 day |
---|---|---|---|---|---|
Inpatient group | |||||
Gross cost savings (in Euros) per 1,000 children | 36,394 | 38,040 | 39,686 | 41,332 | 42,978 |
Herd effect | 21,233 | 22,336 | 23,438 | 24,541 | 25,643 |
Direct effect | 15,161 | 15,704 | 16,248 | 16,791 | 17,335 |
Net cost savings per avoided case (in Euros) | −6 | 6 | 19 | 31 | 44 |
Variation | −4 days | −2 days | Base case | +2 day | +4 days |
---|---|---|---|---|---|
Outpatient group | |||||
Gross cost savings (in Euros) per 1,000 children | 38,755 | 39,220 | 39,686 | 40,152 | 40,617 |
Herd effect | 22,915 | 23,177 | 23,438 | 23,700 | 23,962 |
Direct effect | 15,840 | 16,044 | 16,248 | 16,452 | 16,656 |
Net cost savings per avoided case (in Euros) | 12 | 15 | 19 | 22 | 26 |
Variation | Base case | −5 % | −10 % | −15 % |
---|---|---|---|---|
Net cost savings per avoided case (in Euros) | 19 | 32 | 46 | 59 |