Introduction
The implementation of immunizations against the most common conditions has greatly changed the sphere of healthcare. People who receive vaccinations early in life can avoid the severe consequences of many infections (Talbird et al., 2022). Nonetheless, data demonstrate that immunization rates are not equal across communities, and the latest trends reveal changes within each population segment (Lewycka et al., 2023). The run charts in Figures 1 and 2 (see Appendix) show the rates of childhood immunization for children in the European and Māori groups, respectively.
Chart Analysis
In Figures 1 and 2, one can see that not all four run chart rules are present. The first rule describes shifts – 6 or more points that lie on one of the sides of the median. This phenomenon is evident in the first chart, where the points from October 1, 2018, to March 31, 2020, lie above the median line (Figure 1).
Furthermore, the rates fall below the median line starting on January 1, 2021, indicating another major shift. This rule is similarly present in Figure 2, where two shifts occur. One is above the median line from July 1, 2018, to March 31, 2020, and the other is below the line from April 1, 2020, to the last point on December 31, 2022.
The second rule describes trends in which five or more points indicate an upward or downward progression. The first chart does not showcase any significant trends, as the immunization rates are either stagnant or changing rapidly. For example, between October 1, 2018, and June 30, 2018, no change in immunization rates is observed (Figure 2). Similarly, there are no clear trends in the immunization rates of Māori children, as the chart shows many changes throughout the selected periods, as well as some periods of stagnation.
The third rule considers whether the charts display too many or too few runs – numbers of one or more consecutive data points not on the median. In both charts, the number of runs is extremely low. In Figure 1, out of the 24 total points, 20 are not on the median, and their groupings produce five runs – fewer than the lower limit of 6.
Therefore, one can conclude that there are too few runes in this data set. Looking at Figure 2, none of the 24 points are on the median. The minimum number of runs for this data set is 8, but only 4 are shown on this chart, which is too few.
Finally, while some major changes are evident in both charts, there are no apparent astronomical points. The latter denotes values that significantly differentiate from other values and stand out from the data set. Appearing as outliers, they may showcase a major problem in information collection (Provost & Murray, 2022). In this case, some noteworthy global changes are evident. Still, they do not differ significantly from the nearby values to the extent that would warrant the author considering them astronomical points.
Findings and Conclusions
Overall, the charts reflect common cause variation, as the number of completed immunizations changes slowly, suggesting that some rates may vary due to predictable or persistent issues. Common cause variation explains some problems and events that may occur continuously or be connected to the number of children born and other factors. However, a sharp decline in immunizations for both population groups near the middle of 2020 suggests the possibility of special-cause variation.
For instance, the immunization rate for children in the first run chart sharply drops in July 2020, falling below the median for the first time. After this point, the numbers change significantly and do not return to the same level or frequency as before. The same can be seen in Māori children, though for them this change in rates occurs earlier – in April 2020. One potential reason for this major change is the COVID-19 pandemic, during which families were asked to avoid visiting hospitals unless necessary and to stay home (Dinleyici et al., 2021). This switch could have reduced the number of young patients receiving vaccinations.
The presented data sets have many similarities, some of which are outlined above. For example, both populations experienced a significant decline in immunization rates during the selected period. Moreover, the highest numbers are observed in a single three-month span in the latter quarter of 2019, which may indicate efforts to raise awareness about immunizations in these communities.
However, after this point, both charts show a pronounced negative change, followed by a slight increase, then another major decrease in immunizations. Another vital point is that vaccination rates have been rising since April 2022 across both population segments. Nonetheless, while the two groups seem to move in the same direction, a crucial difference lies in the overall rates. The median percentage of vaccinated European children is 82, whereas it is approximately 62 for Māori youth, as shown in Figures 1 and 2.
The numbers described above provide a foundation for investigating the system’s inequities. On the one hand, the European population has had a high immunization rate, which was rather close to the desired 95%. In 2019, it was over 85%, but in the most recent records, it was under 75% (Figure 1). For Māori children, the situation is even worse – the highest percentage of fully immunized children was reached in 2019, and it was only slightly above 65% (Figure 2).
This number is much lower than that of the European group and is well below the expected rate of 95%. More than that, the current vaccination rate among children does not reach 50%, meaning that over half of the youth are not fully immunized in time to avoid major health problems. The lack of necessary procedures exposes young children to various infections and creates health issues that are difficult to treat and manage.
The decline in immunizations signifies a problem in the healthcare system that cannot provide the necessary medical resources and services to its patients. Immunizations are vital for protecting individuals and populations, and such discrepancies reveal major infrastructure failures (Albers et al., 2022). Therefore, urgent action is necessary to achieve positive change and increase vaccination rates to levels seen in 2019 and higher. For Māori children, additional programs targeting vulnerable groups are essential to eliminate disparities across communities and ensure equal access to resources for all children.
References
Albers, A. N., Thaker, J., & Newcomer, S. R. (2022). Barriers to and facilitators of early childhood immunization in rural areas of the United States: A systematic review of the literature. Preventive Medicine Reports, 27.
Dinleyici, E. C., Borrow, R., Safadi, M. A. P., van Damme, P., & Munoz, F. M. (2021). Vaccines and routine immunization strategies during the COVID-19 pandemic. Human Vaccines & Immunotherapeutics, 17(2), 400-407.
Health New Zealand. (2024). Immunisation coverage.
Lewycka, S., Dasgupta, K., Plum, A., Clark, T., Hedges, M., & Pacheco, G. (2023). Determinants of ethnic differences in the uptake of child healthcare services in New Zealand: Adecomposition analysis. International Journal for Equity in Health, 22(1), 13.
Provost, L. P., & Murray, S. K. (2022). The health care data guide: Learning from data for improvement. John Wiley & Sons.f9.
Talbird, S. E., Carrico, J., La, E. M., Carias, C., Marshall, G. S., Roberts, C. S., Chen, Y. T., & Nyaku, M. K. (2022). Impact of routine childhood immunization in reducing vaccine-preventable diseases in the United States. Pediatrics, 150(3).
Appendix – Run Charts
