Use of prognostic scoring and outcome assessment tools in the admission decision for community-acquired pneumonia.

It has been estimated that between 485,000 27 and 1 million 31 patients each year are hospitalized in the United States for treatment of communityacquired pneumonia. The costs of hospitalizing an individual patient exceed the costs of outpatient care by a factor of 15. 5 A recent estimate of total cost of care for pneumonia in the United States was $8 billion, of which 90% was related to inpatient costs. 30 Some hospital systems have achieved duration of stays of 4 days in uncomplicated pneumonia patients 34,35,37 but, for others, admitting a patient to the hospital can result in a prolonged hospitalization, averaging 9 days. 36 Pneumonia is the sixth leading cause of death overall, 29 and severely ill patients require intensive care admission. Even with intensive care, mortality averaged 36.5% among several series. 18 Inappropriate attempts to treat ill pneumonia patients at home could increase the rate of complications and mortality. The majority of pneumonia patients are treated as outpatients (77% by one estimate 19 ), however, and mortality in outpatient cohorts is low. The determination of whether or not a patient with community-acquired pneumonia can be treated as an outpatient or requires hospitalization is therefore important. Treating less ill pneumonia patients at home also has noneconomic rationales. A study in which 484 outpatients were matched for severity with 265 inpatients demonstrated that the outpatients experienced a more rapid resumption of normal activities. 17 Mortality was low in both groups (none for outpatients, 1.5% for inpatients). Admitting patients to a hospital decreases their activity level and places them at risk for thromboembolic disease. Additional hospital-related complications include catheter-related infections and exposure to resistant bacteria. Furthermore, Coley et al 7 demonstrated that 80% of patients at low risk for mortality from community-acquired pneumonia prefer outpatient treatment. Among hospitalized patients in this study, 60% indicated that they would have preferred ambulatory-based care. Site-of-care decisions were made solely by the medical practitioner in 69% of cases, however, according to a survey of the patients. Only 11% of patients recalled being asked by their physician whether they preferred home versus hospital treatment. The determination of whether or not a patient with community-acquired pneumonia requires hospital admission therefore influences clinical outcomes and patient satisfaction. Investigators have demonstrated considerable variation in hospital admission rates for patients with community-acquired pneumonia across geographic regions. Wennberg et al 38 reviewed hospital bed use for a number of medical conditions in Boston and New Haven hospitals. Based on the number of discharges per capita, Boston physicians were 1.33 times more likely to treat patients with simple pneumonia as inpatients. Similar data have been reported among different hospitals in Maine and Michigan, with some hospitals having more than double the rate of admission per capita than neighboring facilities. 28 Fine et al 16 investigated reasons for variation in the admission decision for community-acquired pneumonia patients as part of the Pneumonia Outcome Research Team (PORT) study. Practitioners making the initial site-of-care decision estimated that 5% of outpatients and 41% of inpatients had a 30-day risk of death greater than 5%. Practitioner-estimated risk of mortality greater than 5% had a strong, independent association with hospitalization, despite the fact that all patients in this study had a predicted probability of death of less than 4%. Additionally, hypoxemia, inability to maintain oral intake, and lack of patient home care support were strongly associated with hospitalization. Practitioners rated the clinical appearance of being "very sick" as important, although the method of assessing this characteristic is uncertain, and interobserver agreement is likely poor. Physician factors associated with hospitalization included the patient having been seen by a medical trainee or by an emergency department physician. Because of variability in determining the need for admission in community-acquired pneumonia, several prognostic scoring and outcome assessment tools have been developed. They are intended to provide support for the hospitalization decision by giving practitioners an objective method of assessing risk of adverse outcomes in patients with pneumonia. The hypothesis is that objective risk stratification will reduce physician uncertainty regarding prognosis, and improve admission decision making.