Risk factors for aspiration pneumonia in frail older people: a systematic literature review.

Objective: To systematically review the risks for aspiration pneumonia in frail older people and the contribution of bad oral health among the risk factors.

Design: Systematic literature review.

Setting: PubMed (Medline), Web of Science, Cochrane Library, EMBASE, and CINAHL were searched for eligible studies, published in English in the period January 2000 to April 2009.

Participants: Frail older people.

Measurements: Only publications with regard to hospitalized, institutionalized, or frail home-dwelling people of 60 years and older were eligible. Two authors independently assessed the publications for their methodological quality. Unadjusted and adjusted odds ratios and their corresponding 95% confidence intervals for respective risk factors related to aspiration pneumonia were extracted. The results were evaluated according to the levels of evidence of the Oxford Centre for Evidence-based Medicine.

Results: A total of 21 publications fulfilled the quality criteria. Evidence level 2a (systematic review with homogeneity of cohort studies) was found for a positive relationship between aspiration pneumonia and age, male gender, lung diseases, dysphagia, and diabetes mellitus; 2b (individual cohort study) for severe dementia, angiotensin I-converting enzyme deletion/deletion genotype, and bad oral health; 3a (systematic review with homogeneity of case-control studies) for malnutrition; 3b (individual case-control study) for Parkinson's disease and the use of antipsychotic drugs, proton pump inhibitors, and angiotensin-converting enzyme inhibitors. The contribution of bad oral health among the risk factors seems limited.

Conclusion: Thirteen significant risk factors were identified: age, male gender, lung diseases, dysphagia, diabetes mellitus, severe dementia, angiotensin I-converting enzyme deletion/deletion genotype, bad oral health, malnutrition, Parkinson's disease, and the use of antipsychotic drugs, proton pump inhibitors, and angiotensin-converting enzyme inhibitors. The contribution of bad oral health seems limited.