title: Risk of hospitalization for community acquired pneumonia with renin-angiotensin blockade in elderly patients: a population-based study.
abstract: OBJECTIVE
  To characterize the 90-day risk of hospitalization with pneumonia among patients treated with different anti-hypertensive drug classes.
  
  
  METHODS
  Population based cohort study using five linked databases.
  
  
  METHODS
  Individuals over the age of 65 who filled a new outpatient prescription for one of four anti-hypertensive medications: ACE inhibitors (n = 86 775), ARBs (n = 33,953), calcium channel blockers (CCB, n = 34,240), beta blockers (BB, n = 35,331) and thiazide diuretics (n = 64 186).
  
  
  METHODS
  Hospitalization with pneumonia within 90 days of a qualifying prescription. We adjusted for ten a priori selected covariates, including age, sex, diabetes and number of visits to a family doctor.
  
  
  RESULTS
  Baseline characteristics of the groups were relatively well matched, except for age, sex, diabetes and frequency of family doctor visits. 128 of the 86 775 patients (0.15%) initiated on an ACE inhibitor and 43 of the 33953 patients (0.13%) of patients initiated on an ARB were hospitalized with pneumonia in the subsequent 90 days. 135 of 64 186 patients (0.21%) initiated on a thiazide, 112 of 35 331 patients (.32%) initiated on a BB, and 89 of 34 240 (0.26%) patients initiated on a CCB achieved the primary outcome. Compared to calcium channel blockers, ACE inhibitors (adjusted OR 0.61, 95% CI 0.46 to 0.81) and ARBs (adjusted OR 0.52, 95% CI 0.36 to 0.76) were associated with a lower risk of pneumonia. No benefit was seen with thiazides (adjusted OR 0.87, 95% CI 0.66 to 1.14) or beta blockers (adjusted OR 1.21, 95% CI 0.91 to 1.60).
  
  
  CONCLUSIONS
  Initiating medications that block the renin angiotensin system, compared to other anti-hypertensive medications, is associated with a small absolute reduction in the 90 day risk of hospitalization with pneumonia.
authors.affiliation: Division of Nephrology, Department of Medicine, Western University, London, Ontario, Canada.
authors.forename: Sachin
authors.initials: S
authors.lastname: Shah
authors.affiliation: Institute for Clinical Evaluative Sciences, London, Ontario, Canada.
authors.forename: Eric
authors.initials: E
authors.lastname: McArthur
authors.affiliation: Division of Nephrology, Department of Medicine, Western University, London, Ontario, Canada.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Farag
authors.affiliation: Division of Nephrology, Department of Medicine, Western University, London, Ontario, Canada.
authors.forename: Michael
authors.initials: M
authors.lastname: Nartey
authors.affiliation: Division of Nephrology, Department of Medicine, Western University, London, Ontario, Canada.
authors.forename: Jamie L
authors.initials: JL
authors.lastname: Fleet
authors.affiliation: Division of Nephrology, Kidney Research Centre, Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Ontario, Canada.
authors.forename: Greg A
authors.initials: GA
authors.lastname: Knoll
authors.affiliation: Division of Nephrology, Toronto General Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada.
authors.forename: S Joseph
authors.initials: SJ
authors.lastname: Kim
authors.affiliation: Division of Nephrology, Department of Medicine, Western University, London, Ontario, Canada; Department of Epidemiology and Biostatistics, Western University, London, Ontario, Canada; Institute for Clinical Evaluative Sciences, London, Ontario, Canada.
authors.forename: Amit X
authors.initials: AX
authors.lastname: Garg
authors.affiliation: Division of Nephrology, Department of Medicine, Western University, London, Ontario, Canada; Department of Epidemiology and Biostatistics, Western University, London, Ontario, Canada; Institute for Clinical Evaluative Sciences, London, Ontario, Canada.
authors.forename: Arsh K
authors.initials: AK
authors.lastname: Jain
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000008:administration & dosage; D000368:Aged; D000369:Aged, 80 and over; D057911:Angiotensin Receptor Antagonists; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000008:administration & dosage*; D000959:Antihypertensive Agents / Q000008:administration & dosage*; D002121:Calcium Channel Blockers / Q000008:administration & dosage; D017714:Community-Acquired Infections / Q000453:epidemiology / Q000517:prevention & control*; D005260:Female; D006760:Hospitalization; D006801:Humans; D006973:Hypertension / Q000188:drug therapy*; D008297:Male; D011014:Pneumonia / Q000453:epidemiology / Q000517:prevention & control*; D012189:Retrospective Studies; D049993:Sodium Chloride Symporter Inhibitors / Q000008:administration & dosage
chemical_list: D000319:Adrenergic beta-Antagonists; D057911:Angiotensin Receptor Antagonists; D000806:Angiotensin-Converting Enzyme Inhibitors; D000959:Antihypertensive Agents; D002121:Calcium Channel Blockers; D049993:Sodium Chloride Symporter Inhibitors