Vaccination coverage among children in Germany estimated by analysis of health insurance claims data

Abstract

In Germany, the national routine childhood immunization schedule comprises 12 vaccinations. Primary immunizations should be completed by 24 mo of age. However, nationwide monitoring of vaccination coverage (VC) is performed only at school entry. We utilized health insurance claims data covering ~85% of the total population with the objectives to (1) assess VC of all recommended childhood vaccinations in birth-cohorts 2004-2009, (2) analyze cross-sectional (at 24 and 36 mo) and longitudinal trends, and (3) validate the method internally and externally. Counting vaccine doses in a retrospective cohort fashion, we assembled individual vaccination histories and summarized VC to nationwide figures. For most long-established vaccinations, VC at 24 mo was at moderate levels (~73-80%) and increased slightly across birth-cohorts. One dose measles VC was high (94%), but low (69%) for the second dose. VC with a full course of recently introduced varicella, pneumococcal, and meningococcal C vaccines increased across birth-cohorts from below 10% above 60%, 70%, and 80%, respectively. At 36 mo, VC had increased further by up to 15 percentage points depending on vaccination. Longitudinal analysis suggested a continued VC increase until school entry. Validation of VC figures with primary data showed an overall good agreement. In conclusion, analysis of health insurance claims data allows for the estimation of VC among children in Germany considering completeness and timeliness of vaccination series. This approach provides valid nationwide VC figures for all currently recommended pediatric vaccinations and fills the information gap between early infancy and late assessment at school entry.

Keywords: Germany; childhood; health services research; vaccination coverage; vaccines.

Figure 1. Vaccination coverage in Germany for birth cohorts 2004 up to 2009, at the age of 24 mo and 36 mo based on health insurance claims data analysis. Upper and lower bounds of confidence intervals are omitted and were ≤0.2 percentage points above or below point estimates. DIP, diphtheria vaccine; TET, tetanus vaccine; PER, pertussis vaccine; IPV, polio vaccine; HIB, Haemophilus influenzae type b vaccine; HEPB, hepatitis B vaccine; PCV, pneumococcal conjugate vaccine; MENC, meningococcal C vaccine; MCV, measles vaccine; MUM, mumps vaccine; RUB, rubella vaccine; VAR, varicella vaccine.

Figure 2. Cumulative vaccination coverage among birth cohorts 2004 to 2009 in relation to age. Depicted are figures for the Associations of Statutory Health Insurance Physicians (ASHIP) regions Saxony-Anhalt and Schleswig-Holstein based on health insurance claims data analysis. Solid lines: 1st or 4th dose, respectively; dashed lines: 2nd dose. TET, tetanus vaccine; MCV, measles vaccine; VAR, varicella vaccine.

Figure 3. Difference of vaccination coverage (VC) point estimates from data analysis of the Association of Statutory Health Insurance Physicians (ASHIP) Schleswig-Holstein and kindergarten entrance examinations (KEE) in the state of Schleswig-Holstein. The compared birth cohorts per vaccination and definitions of vaccination status are listed in Table 2. Boxes indicate lower and upper quartile, the boxes’ length the interquartile range (IQR), horizontal lines indicate medians. Whiskers span all data points within 1.5xIQR of upper or lower quartile, respectively. Dots indicate further data points. DIP, diphtheria vaccine; TET, tetanus vaccine; PER, pertussis vaccine; IPV, polio vaccine; HIB, Haemophilus influenzae type b vaccine; HEPB, hepatitis B vaccine; PCV, pneumococcal conjugate vaccine; MENC, meningococcal C vaccine; MCV, measles vaccine; MUM, mumps vaccine; RUB, rubella vaccine; VAR, varicella vaccine.

Figure 4. Vaccination coverage (VC) estimated from school entrance examinations (SEE) in the state of Saxony-Anhalt and data analysis of the Association of Statutory Health Insurance Physicians (ASHIP) Saxony-Anhalt. Only vaccinations documented on vaccination cards were considered in the examinations. VC is related to the number of children presenting a vaccination card (average case scenario) and the total number of children, irrespective of the presence of a vaccination card (worst case scenario). Definitions of vaccination status are given in Table 2. Vertical lines represent 95% confidence intervals. DIP, diphtheria vaccine; TET, tetanus vaccine; PER, pertussis vaccine; IPV, polio vaccine; HIB, Haemophilus influenzae type b vaccine; HEPB, hepatitis B vaccine; PCV, pneumococcal conjugate vaccine; MENC, meningococcal C vaccine; MCV, measles vaccine; MUM, mumps vaccine; RUB, rubella vaccine; VAR, varicella vaccine.