Risk factors of pneumonia in persons with and without Alzheimer's disease: a matched cohort study.

BACKGROUND: Pneumonia is a very common infection in the cognitively impaired adult population, often leading to long-term deterioration, in physical and cognitive performance. Evidence is lacking on whether chronic comorbidities and drug use are risk factors for pneumonia in persons with Alzheimer's disease (AD). The objective of this study was to investigate the risk factors of pneumonia in community dwellers with and without AD. METHODS: We performed a retrospective register-based study utilizing the Medication Use and Alzheimer's disease (MEDALZ) cohort, which is based on Finnish nationwide healthcare registers and includes all community dwellers who received a verified clinical diagnosis of AD between 2005 to 2011. This study comprised 69,350 persons with AD and 69,350 persons without AD matched by age, gender, and region of residence. Association between comorbidities, drug use, and hospitalization due to pneumonia were assessed using Cox Regression. RESULTS: During the follow-up, 25.0% (n = 17,105) of the AD cohort and 15.8% (n = 10,966) of the non-AD cohort were hospitalized due to pneumonia. Persons with AD had a higher risk of pneumonia also after adjusting for comorbidities (HR 1.76, 95% CI 1.71-1.80). Previous pneumonia was the strongest risk factor for pneumonia in both cohorts. All comorbidities and drug use excluding biological product use were associated with a higher risk of pneumonia, but stronger associations were observed in the non-AD cohort. The risk of hospitalization following psychotropic drug use was proportional to the number of psychotropics utilized. CONCLUSIONS: Pneumonia is a serious, potentially life-threatening illness, and risk factors for pneumonia include several potentially avoidable drugs. In addition, good care of existing comorbidities might prevent pneumonia and related hospitalization.

Hospitalization after Oral Antibiotic Initiation in Finnish Community Dwellers with and without Alzheimer's Disease: Retrospective Register-Based Cohort Study.

BACKGROUND: Persons with Alzheimer's disease (AD) are frequently hospitalized from infection-related causes. There are no previous studies investigating hospitalization associated with antibiotic initiation in persons with AD. OBJECTIVE: To investigate the frequency and risk of hospitalization associated with oral antibiotic initiation among community dwellers with and without AD. METHODS: We performed a retrospective register-based study utilizing register-based Medication Use and Alzheimer's disease (MEDALZ) cohort. It includes all community dwellers diagnosed with AD during 2005-2011 in Finland and their matched comparison persons without AD. Antibiotic use was initiated by 34,785 persons with and 36,428 without AD. Drug use data were collected from Prescription Register and comorbidities from Special Reimbursement and Hospital Care Registers. Infection diagnoses were collected from the Hospital Care Register. Factors associated with hospitalization were estimated utilizing logistic regression models. RESULTS: Risk of hospitalization following antibiotic initiation was higher among antibiotic initiators with AD than without AD (adjusted odds ratio, aOR, 1.37, 95% Cl 1.28-1.46).Strongest association with hospitalization was found for oral glucocorticoid use, aOR 1.41 (1.25-1.59); epilepsy, aOR 1.33 (1.10-1.63); and active cancer, aOR 1.30 (1.14-1.49). Among initiators of cephalexin, pivmecillinam, amoxicillin/amoxicillin, and enzyme inhibitor and doxycycline, persons with AD were more frequently hospitalized than persons without AD. A quarter of hospitalized antibiotic initiators had infection diagnosis in their hospital care records. CONCLUSIONS: Persons with AD initiating an antibiotic had a higher risk for hospitalization than antibiotic initiators without AD. Further research is needed to determine whether infection-related hospitalization could be reduced.