Pneumococcal disease is a major cause of disease worldwide that can affect the lungs, bloodstream, and coverings of the brain and spinal cord. Examples of pneumococcal disease include community-acquired pneumonia and meningitis. While healthy adults are at risk of developing pneumococcal disease, adults with chronic conditions such as diabetes, chronic heart failure, and chronic liver disease are at greater risk of developing the disease due to a weakened immune system. The pneumococcal polysaccharide vaccine was recommended for individuals with medical conditions in 1992. Data from 2009 show that most adults are not being vaccinated with the vaccine (only 34.4% received the vaccine in 2009). To our knowledge, the proportion of adults with chronic conditions who have been vaccinated for pneumococcal disease is unknown. We propose to estimate the risk of adults with chronic conditions developing pneumococcal diseases, the associated costs, and determine the percentage of adults with chronic conditions who received the pneumococcal vaccination.
The risk of pneumococcal disease in individuals with underlying medical conditions is not well characterized in the UK. The UK currently recommends pneumococcal vaccination for certain ‘At Risk’ adult individuals. However, reports on vaccine coverage rates (VCR) for this population are very limited. The last uptake rate for pneumococcal vaccination in the UK was published in 2009 and only showed a vaccine coverage rate of 34.4%. The primary objective of this study is to estimate the clinical and economic burden of pneumococcal disease and examine the pneumococcal VCR in adults aged 18 to 64 years old with underlying medical conditions using 2011-2016 Clinical Practice Research Datalink (CPRD) data. This retrospective cohort study will be conducted using anonymized electronic health record (EHR) data from 2011-2016. Individuals aged between 18 and 64 years old within the specified clinical risk groups recommended for pneumococcal vaccination in the UK will be included if they had continuous EHR data for 24 months before and at least 12 months after the diagnosis of the underlying medical conditions. Descriptive statistics including frequencies and percentages for categorical variables, mean (SD) for continuous variables, will be calculated. Rates and rate ratios of pneumococcal diseases will be reported among patients with each chronic condition compared with age-matched healthy counterparts; rate of pneumococcal vaccination will be reported among patients with each underlying condition by length of follow-up since diagnosis (ranging from 1 to 4 years). The number and proportion of patients utilizing healthcare resources (i.e. number of physician visits, prescriptions, and treatment costs) will be described. Multivariable logistic regression to determine factors associated with pneumococcal polysaccharide vaccination.
Health Outcomes to be Measured:
Pneumococcal VCR in adults aged 18 years onwards with underlying medical conditions; incidence rate of pneumococcal diseases in adults aged 18 years onwards with underlying medical conditions; healthcare resource utilization (i.e. general practice visit, prescription, cost)