Lower respiratory infection (LRI), including pneumonia, is a leading cause of hospitalization and death among nursing home residents. Unfortunately, pneumonia often is not diagnosed until residents are already quite sick and need to be hospitalized. In the Missouri LRI Study, which was supported in part by the Agency for Healthcare Research and Quality (HS08551), David R. Mehr, M.D., M.S., of the University of Missouri-Columbia School of Medicine and his colleagues developed a simple clinical prediction rule that can identify nursing home residents at very high risk for pneumonia. The researchers also developed a predictive tool that can be used to identify nursing home residents at low risk for death from lower respiratory infection.
The Missouri LRI Study involved more than 1,000 residents of 36 nursing homes in central Missouri and the St. Louis, MO, area between August 15, 1995 and September 30, 1998. Because all facilities involved in this study were in central or eastern Missouri, the researchers point out that their findings should be validated in other States where factors affecting mortality may be different. The two studies are described here.
Mehr, D.R., Binder, E.F., Kruse, R.L., and others. (2001, November). "Clinical findings associated with radiographic pneumonia in nursing home residents." Journal of Family Practice 50(11), pp. 931-937.
Since elderly patients show few signs and symptoms of pneumonia (for example, they often do not have a fever), clinicians make few and sporadic visits to nursing homes, and radiology facilities are rarely on the premises, sick nursing home residents may be sent to the hospital emergency department for evaluation. Clinicians who care for nursing home residents clearly could benefit from a simple clinical tool to identify pneumonia.
In the Missouri LRI study, the researchers examined which nursing home residents with signs or symptoms of LRI had evidence of pneumonia on chest x-rays in order to deduce which symptoms suggested high risk of pneumonia. Their findings confirmed that pneumonia in nursing home residents usually is associated with few symptoms. Among 2,334 episodes of illness in 1,474 nursing home residents, 45 percent of chest x-ray reports suggested possible or definite pneumonia. Yet in 80 percent of pneumonia episodes, patients had three or fewer respiratory or general symptoms. However, only 8 percent of patients had no respiratory symptoms. Eight factors independently predicted pneumonia: increased pulse, increased respiratory rate (30 or higher), temperature of 38 degrees C or higher, somnolence or decreased alertness, presence of acute confusion, lung crackles on auscultation, absence of wheezing, and elevated white blood cell count.
The researchers created a simple scoring system based on these factors. The 33 percent of residents scoring three or more points had more than a 50 percent probability of pneumonia, and the 24 percent of residents who had a score of 2 points had a 44 percent probability of pneumonia. The researchers conclude that doctors should consider treating residents at high risk of pneumonia—based on at least two or three points on the scoring system—without obtaining a chest x-ray. For residents with a score of 1 or less, doctors should obtain an x-ray as a guide to treatment.
Mehr, D.R., Binder, E.F., Kruse, R.L., and others. (2001, November 21). "Predicting mortality from lower respiratory infection in nursing home residents: The Missouri LRI Study." Journal of the American Medical Association 286(19), pp. 2427-2436.
LRI (pneumonia, bronchitis, and tracheobronchitis) is the leading cause of hospitalization and mortality among nursing home residents. Studies have shown that hospitalization of nursing home residents is sometimes inappropriate and can be associated with complications or discomfort. Because many nursing home residents are chronically ill and near the end of life, clinicians faced with a patient with an LRI should first determine appropriate therapeutic measures (aggressive care, limited curative treatment, or strictly palliative care). Clinicians then need to determine LRI severity to help them decide on specific treatments and whether to transfer the resident to the hospital. These researchers designed a new tool that helps identify nursing home residents who are at relatively low risk of death from LRI and thus may be safely treated in the nursing home without transferring them to a hospital.
Dr. Mehr and colleagues prospectively identified 1,406 episodes of LRI in 36 Missouri nursing homes. Within 30 days of diagnosis, 27 percent of episodes involved hospitalization; mortality was 15 percent. The researchers developed an eight-variable model to predict 30-day mortality, including serum urea nitrogen, white blood cell count, body mass index, pulse rate, activities of daily living status, absolute lymphocyte count of less than 800/µL, male sex, and deterioration in mood over 90 days. In developing this new model, the researchers built on the work of earlier research funded by AHRQ and conducted by the Patient Outcomes Research Team (PORT) on Community-Acquired Pneumonia. The PORT developed and validated the Pneumonia Severity Index (PSI), which is used to identify pneumonia patients living in the community who can be treated safely at home.
Because the PSI assigns higher risk based on age and other variables common to elderly people, it predisposes most nursing home residents with respiratory conditions to hospitalization, whether or not their condition actually warrants it. Focusing on nursing home residents allowed the researchers to identify risk factors that specifically apply to this population. Compared with the PSI, the resulting model gives more weight to variables such as activities of daily living (ADLs, e.g., grooming, using the toilet, eating, locomotion), mood decline, and markers of poor nutritional status.