Kandalyn Fogg
Biology Lab 1615
Final Research Paper
Pneumonia has always been a leading cause of death and illness in many parts of
the world, particularly England. It is especially more prevalent in the elderly populations.
Research on the subject found a 34% increase in pneumonia hospital admissions between
1997-1998 as well as 2004-2005. As stated previously, the increase was more prevalent
in the elderly but this was not the only factor. Patients with co-existing conditions
admitted for pneumonia also increased significantly. Demographic changes, age, and coexisting conditions are only part of what scientists believe to be the cause of the increase
of hospital admission for pneumonia between the two time frames. Changes in increase
could also be due to other population factors, changes in HES coding, changes in the
health service organization, other biological phenomenon or a broader combination of
these various scenarios. Increases in hospitalization due to pneumonia were also noted in
the United States, Denmark ,and the Netherlands during the specified time frames
previously mentioned. These increases have occurred despite widespread influenza and
pneumococcal vaccination programs. The leading cause for community acquired
pneumonia is “streptococcus pneumoniae”; research has found that the 23 valent
pneumococcal polysaccharide vaccine that is currently recommended for the elderly
especially throughout the United Kingdom has little effect against non bacteremic
pneumonia. Because of this new 7- valent pneumococcal conjugate vaccine (PCV7) was
introduced into the United Kingdom infant immunization schedule in September 2006 to
attempt to bring the future pneumonia diagnoses, hospital admissions, and death numbers
down. In the United States, the experience found with the PCV7 suggested that by
reducing carriage; thus the opportunity for transmission of vaccine types, vaccination can
therefore lead to a reduction in invasive pneumococcal disease, as well as pneumonia in
unvaccinated cohorts. This article reports on the epidemiology of pneumonia before the
PCV7 vaccination was introduced by examining trends in hospital admissions,
comparing and analyzing the data collected, and determining the meaning or
significance of their ending conclusions from their admission case studies occurring in
England during an eight year period. (1997-2005)
Research on the increasing hospital admissions due to pneumonia began in order
to better understand the relationships between age, co-existing conditions, demographic
change, other population factors, changes in HES coding, changes in the health service
organization, or other biological phenomenon. Based on the data collected after
implementing the PCV7 vaccine, the overall number of diagnoses, admissions, and
deaths due to pneumonia went down. This result leads scientists to question what the
initial cause (or causes) for the initial increase of the disease in previous years. Scientists
predicted that certain individuals or groups of the population (such as the elderly or those
with pre- existing conditions) played a part, but they also believed that there was more to
it.
The research conducted to write this article centered around the numbers and
types of hospital admissions due to pneumonia. Though upon further study, individuals
that were discovered to have developed pneumonia after admission- were also included in
the study. Information on these admissions/cases were gathered from the HES (hospital
episode statistics) which came form the NHS (national health service) information center
for health and social care; these sources contain details of all admissions to the NHS
hospitals in England. Through the HES data base, scientists and researchers were able to
get important details and information about the length of time of the admission stay, as
well as how many pneumonia episodes were recorded during the patients stay. A patient
identifier was created based on the patient’s birth date, postal code, and sex to maintain
anonymity. Other information such as cases of pneumonia that directly resulted in death
were also recorded; co-existing conditions were also grouped into 4 levels: non coexisting conditions, mild, moderate, or severe co-existing conditions. Statistics were
gathered to compare the effects of alcohol consumption among patients, as well as the
seasonal effects. It was believed that many if not all of these aspects correlated directly to
the rising cases of pneumonia.
Scientists came up with various results in conclusion to their research. In cases
where the primary diagnoses was pneumonia, researchers found an approximate increase
of 72,060 between 1997-1998 and 2004-2005. An overall age standardized incidence rate
of 34% was also noted among the primary diagnoses studies. Patients that developed
pneumonia after their primary diagnosis increased in number from 110,143 to 153,312;
the same age standardized incidence rate also increased among the patient population.
(meaning the elderly were more susceptible) Co-existing conditions found in patients
varied over time and age. In all age groups, the proportion of patients with co-existing
conditions increased. In addition, each year 1% of the overall patients had an additional
alcohol related code recorded. These codes were slightly more common in those over the
age of 65. The length of stay was also studied, and averaged out to 3 days, increasing
with the patient’s age. Admission patterns were also analyzed, and researchers found that
admissions occurred more often over the weekend. Incidence of admission was also
noted more often during the winter months. Mortality rates were significantly higher in
older adults. The odds of death were also much higher between 1997-1998 than in 20042005. All the information gathered by researchers and scientists supports the theory that
prior to the PCV7 vaccination, multiple factors contributed to the previous rise of
pneumonia cases throughout the United Kingdom.
It is important to understand that there are often multiple causes for a peak or
significant prevalence in certain populations of illnesses like pneumonia. Without this
additional knowledge, further interventions would be impossible. For instance, in this
article, multiple contributing factors were found to influence the rise of pneumonia. This
information is crucial to prevent future excessive outbreaks, ensuring the success of the
PCV7 vaccination. Understanding the past helps us to ensure a better future.