Pneumonia Severity Index (PSI) Lacking in Breadth of Applicability

Abstract

The purpose of a community-acquired pneumonia (CAP) severity of illness scoring system is to assist clinicians with the hospital admission decision. Patient safety, convenience, and cost are the overriding concerns. The Pneumonia Severity Index (PSI) is incorporated into many CAP treatment guidelines, but it has not attained wide clinical application. Although the PSI might be helpful in some studies, as pointed out by Yearly et al, it is perceived to be of limited practical use, particularly in those in whom socioeconomic factors may affect outcome but possibly not immediate mortality. For patients with hypoxia, unstable vital signs, shock, or severe medical comorbid illness, no scoring system is needed; inpatient care is required. It is those in whom underlying psychiatric illness, substance abuse, homelessness, or age-related fragility dictate hospital stay that the PSI fails to incorporate risks for complications. In 2 studies in which clinicians were specifically instructed to use the PSI guideline, between 31 to 43% of patients in the low-risk categories I-III were still admitted.1Niederman M.S. What is the prognosis for using the pneumonia severity index to make site-of-care decisions in community-acquired pneumonia?.Chest. 2003; 124: 2051-2053Crossref PubMed Scopus (13) Google Scholar, 2Atlas S.J. Benzer T.I. Borowsky L.H. et al.Safely increasing the proportion of patients with community-acquired pneumonia treated as outpatients: an interventional trial.Arch Intern Med. 1998; 158: 1350-1356Crossref PubMed Scopus (218) Google Scholar, 3Marrie T.J. Lau C.Y. Wheeler S.L. et al.CAPITAL study investigatorsA controlled trial of a critical pathway for treatment of community-acquired pneumonia Community-acquired pneumonia intervention trial assessing levofloxacin.JAMA. 2000; 283: 749-755Crossref PubMed Scopus (642) Google Scholar The present study by Marrie et al confirms this lack of utility, particularly in an urban inner-city setting.4Marrie T.H. Huang J.Q. Low-risk patients admitted with community-acquired pneumonia.Am J Med. 2005; 118: 1357-1363Abstract Full Text Full Text PDF PubMed Scopus (29) Google Scholar Cost savings are more likely to come from short stay, brief observation, and early discharge until pneumonia assessment scoring systems factor in risks for morbidity and poor outcome in addition to death. A pneumonia severity of illness scoring system will not be useful if it is not used in the field, and it will not be widely accepted into practice until one is derived which is more comprehensive in its guidance for clinicians. The purpose of a community-acquired pneumonia (CAP) severity of illness scoring system is to assist clinicians with the hospital admission decision. Patient safety, convenience, and cost are the overriding concerns. The Pneumonia Severity Index (PSI) is incorporated into many CAP treatment guidelines, but it has not attained wide clinical application. Although the PSI might be helpful in some studies, as pointed out by Yearly et al, it is perceived to be of limited practical use, particularly in those in whom socioeconomic factors may affect outcome but possibly not immediate mortality. For patients with hypoxia, unstable vital signs, shock, or severe medical comorbid illness, no scoring system is needed; inpatient care is required. It is those in whom underlying psychiatric illness, substance abuse, homelessness, or age-related fragility dictate hospital stay that the PSI fails to incorporate risks for complications. In 2 studies in which clinicians were specifically instructed to use the PSI guideline, between 31 to 43% of patients in the low-risk categories I-III were still admitted.1Niederman M.S. What is the prognosis for using the pneumonia severity index to make site-of-care decisions in community-acquired pneumonia?.Chest. 2003; 124: 2051-2053Crossref PubMed Scopus (13) Google Scholar, 2Atlas S.J. Benzer T.I. Borowsky L.H. et al.Safely increasing the proportion of patients with community-acquired pneumonia treated as outpatients: an interventional trial.Arch Intern Med. 1998; 158: 1350-1356Crossref PubMed Scopus (218) Google Scholar, 3Marrie T.J. Lau C.Y. Wheeler S.L. et al.CAPITAL study investigatorsA controlled trial of a critical pathway for treatment of community-acquired pneumonia Community-acquired pneumonia intervention trial assessing levofloxacin.JAMA. 2000; 283: 749-755Crossref PubMed Scopus (642) Google Scholar The present study by Marrie et al confirms this lack of utility, particularly in an urban inner-city setting.4Marrie T.H. Huang J.Q. Low-risk patients admitted with community-acquired pneumonia.Am J Med. 2005; 118: 1357-1363Abstract Full Text Full Text PDF PubMed Scopus (29) Google Scholar Cost savings are more likely to come from short stay, brief observation, and early discharge until pneumonia assessment scoring systems factor in risks for morbidity and poor outcome in addition to death. A pneumonia severity of illness scoring system will not be useful if it is not used in the field, and it will not be widely accepted into practice until one is derived which is more comprehensive in its guidance for clinicians.