Main characteristics of case-control studies included in review
| Study | Location, study design | Data length (years) | Data source; period of study | Patients | Matching | ACE inhibitor or ARB | No with pneumonia v controls (total) | Mean (SD) age | Outcome | Ascertainment | Outcome adjustments | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Drug use | Outcome | |||||||||||
| Nested case-control studies: | ||||||||||||
| Etminan 200621 | Canada, retrospective | 5.0 | Databases of administrative healthcare programmes offered to residents of Quebec; 1996-2000 | Patients who went for coronary revascularisation procedure and had incident pneumonia after hospital discharge | Ratio 1:20; time of follow-up, same calendar year of cohort entry, and age | NR | 1666 v 33315 (47 148) | 71 (8.3) | Admitted to hospital with pneumonia | Database records | ICD-9 codes | Sex, comorbidities, previous heart failure, number of physician visits, and drugs used |
| Mukamal 201074 | USA, Puerto Rico, and US Virgin Islands, retrospective | 7.0 | Data on adults with hypertension insured by large commercial plans; January 2000-November 2007 | Patients with hypertension and incident pneumonia | Ratio 1:10; age, sex, residence, insurance plan, subscriber status, and date of enrolment | NR | 7429 v 73571 (81 000) | 58.2 (12.7) | Pneumonia | Records of filled pharmacy claims | ICD-9 codes | Diabetes, inflammatory diseases, cardiovascular diseases, chronic kidney disease, organ transplantation, and drugs used |
| Case-control studies: | ||||||||||||
| Okaishi 199975 | Japan, prospective18 (hospital-based study) | 1.0 | Department of Internal Medicine of Hanwa-Senbooku Hospital; July 1996-June 1997 | Patients aged ≥65 years with fatal or non-fatal pneumonia | Ratio 1:4; sex and age | Temocapril, alacepril, cilazapril, captopril | 55 v 220 (275) | 81.1 (7.7) | Admission for pneumonia | Hospital computerised pharmacy database | Personal physicians. Questionable events reviewed by physician blinded to patients’ drugs | Age, sex, dementia, hypoalbuminemia, bedridden state, lung disease, and antacid use |
| El Solh 200476 | USA, retrospective | 4.0 | Electronic database from 3 tertiary care hospitals; March 1999-August 2003 | Patients aged >65 years readmitted to hospital with pneumonia over 1 year from first episode | Ratio 1:1; age, admission date, and residence | NR | 204 v 204 (408) | 78.5 (8.2) | Hospital admission for pneumonia | Database records | Database records | Multivariate, not defined |
| Takahashi 200577 | Japan, retrospective (hospital based study) | 0.7 | April 1999-November 1999 | Patients with admission period >3 months who presented with fatal or non-fatal pneumonia | Ratio 1:4; sex and age | Temocapril | 105 v 420 (525) | 82.8 (8) | Pneumonia | Hospital computerised pharmacy database | Information collected by full time nurses under physicians’ supervision. Questionable events were reviewed by physician without knowledge of patients’ drugs | Age, sex, bedridden state, congestive heart failure, diabetes mellitus, lung disease, ACE polymorphism, and use of other antihypertensives |
| Van de Garde 200622 | Netherlands, retrospective (population based study) | 6.0 | PHARMO record linkage system and PRISMANT records; January 1995-December 2000 | Patients admitted to hospital with primary diagnosis of pneumonia | Ratio 1:4; age and sex | NR | 1108 v 3817 (4925) | 67 (0.51) | Hospital admission for community acquired pneumonia | ATC classification | ICD-9 codes | Diabetes, respiratory diseases, heart failure, use of systemic corticosteroids, and use of gastric acid suppressants |
| Van de Garde 200778 | UK, retrospective | 14.0 | UK General Practice Research Database; June 1987-January 2001 | Patients with diabetes who had first diagnosis of pneumonia | Ratio 1:4; age, sex, type of stroke, NIH Stroke Scale score, side and depth of stroke | Cilazapril, captopril, enalapril, fosinopril, lisinopril, perindopril, quinapril, ramipril, trandolapril | 4719 v 15 332 (20 041) | 73 (11) | Pneumonia | Receipt of prescriptions within year before index date | Codes of Oxford Medical Information System | Age, congestive heart failure, history of stroke, evident alcohol misuse, pulmonary diseases, smoking, number of general practitioner visits a year, oral glucocorticoid use, statin use, pneumococcal vaccination, and use of gastric acid suppressants |
| Marciniak 200979 | USA, retrospective | 4.0 | Stroke rehabilitation registry database, September 1999-August 2003 | Patients admitted for inpatient rehabilitation within 90 days after stroke onset who developed pneumonia | NR | NR | 36 v 36 (72) | 66.3 (12.1) | Pneumonia | Medical records | Medical records, chest radiography confirmation | Presence of tracheostomy or feeding tube |
ACE=angiotensin converting enzyme; ARB=angiotensin receptor blocker; NR=not reported; ATC=anatomical therapeutic chemical system.