A study of the impact of statins, ACE inhibitors and gastric acid suppressants on pneumonia risk and mortality using the Health Improvement Network Database

Myles, Puja Runa (2009) A study of the impact of statins, ACE inhibitors and gastric acid suppressants on pneumonia risk and mortality using the Health Improvement Network Database. PhD thesis, University of Nottingham.

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Pneumonia is a common diagnosis in general practice and is associated with significant morbidity and mortality. Current estimates of pneumonia incidence in the UK are based on studies more than a decade ago and little is known about longer term outcomes in pneumonia patients. Though much is known about the aetiology of pneumonia and predictors of mortality, an emerging area for research is the relationship between commonly prescribed drugs in general practice and pneumonia.

The aims of this thesis were first, to determine overall incidence and mortality for pneumonia and how these vary by socio-demographic characteristics like age, sex, deprivation; and second, to investigate whether statins, angiotensin converting enzyme inhibitors (ACEIs) and gastric acid suppressants like proton pump inhibitors (PPIs) and histamine 2 receptor antagonists (H2RAs) modify the risk of acquiring pneumonia and its prognosis.

This study used data from The Health Improvement Network (THIN) database, a longitudinal database of anonymised computerised medical patient records from 330 United Kingdom (UK) general practices at the time of data extraction in 2006. A cohort design was used to determine pneumonia incidence and mortality in the UK. Case-control, case-series and cohort study designs were used to investigate associations between the various drug exposures and pneumonia. The overall incidence of pneumonia was 237 per 100,000 person-years (95 % confidence interval (CI): 235 to 239) and this rate was stable between 1991 and 2003. Pneumonia was more common in men and in children under the age of four years and adults over the age of 65 years. There was an increased incidence of pneumonia with higher levels of socioeconomic disadvantage. Pneumonia cases showed much higher all-cause mortality as compared to the general population, both in the short and long-term and this increase was independent of underlying comorbidity. After adjusting for potential confounders, current prescriptions for statins and ACE inhibitors were associated with a significant reduction in the risk of acquiring pneumonia. Current prescriptions for PPIs were associated with an increased risk of pneumonia. With regards the impact on mortality: the use of statins was associated with a lower risk of short and long-term mortality following pneumonia whereas the use of ACEIs was associated with a decreased mortality risk only in the short-term. No relationship was observed between prescriptions for PPIs, H2RAs and pneumonia mortality. This study shows that caution must be exercised while prescribing proton pump inhibitors especially in patients known to be at high risk of pneumonia. There is also a potential role for statins in preventing pneumonia in at-risk patients and improving pneumonia outcomes but this will necessitate clinical trials to determine adequate dose, duration and safety profiles before any prescribing policy recommendations are made.

Item Type: Thesis (University of Nottingham only) (PhD)
Supervisors: Hubbard, R.
McKeever, T.
Keywords: Pneumonia, Pharmacoepidemiology, The Health Improvement Network Database, General Practice database, Statins, ACE inhibitors, Gastric acid suppressants
Subjects: W Medicine and related subjects (NLM Classification) > WC Communicable diseases
Faculties/Schools: UK Campuses > Faculty of Medicine and Health Sciences > School of Community Health Sciences
Item ID: 10957
Depositing User: EP, Services
Date Deposited: 19 Jul 2010 13:47
Last Modified: 19 Oct 2017 11:40
URI: https://eprints.nottingham.ac.uk/id/eprint/10957

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