Predicting 2-Year Risk of Developing Pneumonia in Older Adults without Dementia.

OBJECTIVES: To develop three prognostic indices of varying degree of required detail for 2-year pneumonia risk in older adults.

DESIGN: Retrospective cohort study.

SETTING: Group Health (GH), an integrated healthcare delivery system.

PARTICIPANTS: Community-dwelling dementia-free individuals aged 65 and older who had been GH members for at least 2 years before start of follow-up and were enrolled in the Adult Changes in Thought study (N = 3,375; development cohort, n = 2,250; validation cohort, n = 1,125.

MEASUREMENTS: Potential pneumonia risk factors were identified from questionnaire data and interviewer assessments of functional status, medical history, smoking and alcohol use, cognitive function, personal care, and problem solving. Risk factors were also identified based on physical measures such as grip strength and gait speed and administrative database information on comorbid illnesses, laboratory tests, and prescriptions dispensed. Incident community-acquired pneumonia was defined presumptively from administrative data and validated using medical record review.

RESULTS: Participants (59% female) contributed 12,998 visits at which risk factors were assessed; 642 pneumonia events were observed during follow-up. Age, sex, chronic obstructive pulmonary disease, congestive heart failure, body mass index, and use of inhaled or oral corticosteroids were critical predictors in all prognostic indices. A risk score based on these seven variables, information on which is commonly available in electronic medical records (EMRs), had equal or better performance (c-index = 0.69 in the validation cohort) than scores including more-detailed data such as functional status.

CONCLUSION: Data commonly available in EMRs can stratify older adults into groups with varying subsequent 2-year pneumonia risk.