People who have pneumonia or other severe infections caused by pneumococcus bacteria are at higher risk of dying than the general population of the same age, for months and even years after the infection. This may be because the long-term medical conditions such as diabetes which predispose people to pneumococcal infection also affect long-term survival. It is not known whether severe pneumococcal infection itself increases the risk of death in the medium to long term, once the infection has passed.
This study will describe deaths following severe pneumococcal infection, using anonymised national data reports for 14000 people aged 65 or over years with confirmed severe pneumococcal infections, which includes their long-term medical conditions as reported by their GPs. We will compare cases to a cohort of the general population aged 65 years or over or over drawn from the CPRD database. We will compare deaths among cases (following pneumococcal infection) to deaths among the general population, controlling for age, sex, and long-term conditions.
This analysis will help clarify whether poor survival after pneumococcal infection is explained by the pre-existing health conditions of people who experience pneumococcal infection, or whether it could be a long-term consequence of the pneumococcal infection. This study will enable better understanding of the long-term consequences of pneumococcal infection, and the benefits of vaccination against pneumococcal disease.
Cohort studies have found that 5-10 year mortality is high among survivors of invasive pneumococcal disease. However, previous studies have not adjusted for pre-existing comorbidities, which could explain this finding.
This study will compare survival among an anonymised UK Health Security Agency dataset of over 14000 individuals aged 65 years or over with laboratory-confirmed invasive pneumococcal disease from 1 January 2012 to 31 December 2019, to a comparator cohort drawn from CPRD of members of the general population aged 65 years or over. The comparator cohort will be individuals aged 65 years or over and active in the Clinical Practice Research Database 2012-2019. The two datasets will not be linked, and both datasets will remain fully anonymised.
The study will use a matched cohort design to compare long-term survival among cases (from 120 days after infection onset to latest mortality data linkage for end of follow up) to long-term survival among the comparator cohort. Up to five comparators will be selected per case, matching on age and sex in calendar date order. Multivariable Cox or Poisson regression models will be used to adjust for deprivation, ethnicity, and co-morbidities.
This will enable better understanding of the long-term prognosis of IPD and inform improved estimates of the benefits and cost-effectiveness of pneumococcal vaccination.
Death from any cause
Edward Parker - Chief Investigator - London School of Hygiene & Tropical Medicine ( LSHTM )
Edward Parker - Corresponding Applicant - London School of Hygiene & Tropical Medicine ( LSHTM )
Anne Suffel - Collaborator - London School of Hygiene & Tropical Medicine ( LSHTM )
Daniel Grint - Collaborator - London School of Hygiene & Tropical Medicine ( LSHTM )
Kathryn Mansfield - Collaborator - London School of Hygiene & Tropical Medicine ( LSHTM )
Nick Andrews - Collaborator - Public Health England
Shamez Ladhani - Collaborator - Public Health England
Zahin Amin-Chowdhury - Collaborator - Public Health England
Edward Parker - Collaborator - London School of Hygiene & Tropical Medicine ( LSHTM )
HES Admitted Patient Care;ONS Death Registration Data;Patient Level Index of Multiple Deprivation;Practice Level Index of Multiple Deprivation