To investigate the effect of angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers on pneumonia hospitalization in patients with stroke history in Taiwan.
We conducted a case-crossover study using the National Health Insurance Research Database in Taiwan during the period from 1998 to 2007. Patients who had stroke history and were subsequently admitted for pneumonia were enrolled for analysis. The status of exposure to angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers 1–30 days prior to admission (case period) was compared to that during 91–120 days and 181–210 days before admission (control periods) for each patient. Conditional logistic regression was used to estimate the odds ratio (OR) and 95% confidence interval (95% CI) for the association between pneumonia and use of angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers.
In this study, 13 832 patients with incident pneumonia from the stroke patient population were enrolled. After adjustment for time-varying confounding factors, angiotensin-converting enzyme inhibitor use was associated with a decreased pneumonia risk (OR 0.70; 95% CI 0.68–0.87) and a significant dose–response relationship (P < 0.01). The pneumonia risk associated with angiotensin II receptor blockers use was not significant (OR 1.02; 95% CI 0.87–1.19).
Our study revealed a significant protective effect with dose–response relationship of angiotensin-converting enzyme inhibitor use on hospitalization for pneumonia among stroke patients. Further studies to confirm the protective effect of angiotensin-converting enzyme inhibitor use on pneumonia risk are warranted.
aDepartment of Family Medicine, En Chu Kong Hospital
bThe Division of Health Technology Assessment, Center for Drug Evaluation
cDepartment of Psychiatry, Far Eastern Memorial Hospital
dGraduate Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taiwan
Correspondence to Mei-Shu Lai, Graduate Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, 5Fl. No. 17, Hsu Chow Road, Taipei 100, Taiwan.Tel: +886 2 33668028; fax: +886 2 23511955; e-mail: firstname.lastname@example.org
Abbreviations: 95% CI, 95% confidence intervals; ACEi, angiotensin-converting enzyme inhibitor; ARB, angiotensin II receptor blockers; ATC, anatomical therapeutic chemical; DDD, defined daily dose; H2RA, histamine type 2 receptor antagonist; ICD-9 CM, International Classification of Disease 9th Clinical Modification; NHI, National Health Insurance; NHIRD, National Health Insurance Research Database; OR, odds ratios; PPI, proton pump inhibitors
Received 18 March, 2012
Revised 3 June, 2012
Accepted 2 July, 2012