The CURB-65 score estimates mortality risk for community-acquired pneumonia and helps guide inpatient versus outpatient treatment decisions.
The CURB-65 score can be used in the emergency department setting to risk stratify patients who present with community-acquired pneumonia (CAP). The score can be computed quickly, uses patient information that is often already available, and provides an excellent risk stratification for CAP. It can also help to facilitate better utilization of resources and treatment initiation.
The CURB-65 score does not assign points for comorbid illness and nursing home residence, because the original study accounted for many of those conditions. The score includes points for confusion and blood urea nitrogen levels, which could be attributable to a variety of factors in an acutely ill elderly patient. The CURB-65 score may not identify patients requiring intensive care unit admission as well as the pneumonia severity index (PSI). The CURB-65 score offers equal sensitivity of mortality prediction due to CAP as compared with the PSI. Notably, CURB-65 has a higher specificity (74.6%) than the PSI (52.2%). For patients scoring high on CURB-65, it is prudent to ensure initial triage has not missed the presence of sepsis. Evaluation for systemic inflammatory response syndrome criteria would be beneficial for these patients.
While pneumonia is often viral in nature, typical practice is to provide a course of antibiotics because the pneumonia could be bacterial. Disposition (inpatient vs outpatient) often dictates further care and management, including laboratory testing and blood cultures.
Sagar Patel, MD
The original CURB-65 study was a retrospective review of 3 prospective studies from the United Kingdom, New Zealand, and the Netherlands, including a total of 1068 patients. The 5-point score was developed to stratify CAP patients into different treatment groups, using confusion, blood urea nitrogen level, respiratory rate, blood pressure, and age as the score components. The study included comorbidity variables such as chronic lung disease, chronic liver disease, congestive heart failure, cardiovascular disease, and diabetes mellitus, and controlled for these variables when developing the relevant risk-stratification criteria.
The initial validation study was conducted in India and included 150 patients. More recent validation studies conducted in other countries have shown increasing mortality and need for intubation with increasing CURB-65 scores, at rates ranging from 0% to 1.1% for a score of 0 and from 17% to 60% for a score of 5. When combined, these studies included more >3100 patients.
John Macfarlane, MD
Original/Primary Reference
Validation References
The PSI/PORT score estimates mortality for adult patients with community-acquired pneumonia.
The pneumonia severity index (PSI), or pneumonia Patient Outcomes Research Team (PORT) score, can be used in the emergency department setting to risk stratify patients who present with community-acquired pneumonia. In most situations, however, the CURB-65 score is easier to use and requires fewer inputs.
Because the PSI assigns points by absolute age, it may underestimate severe pneumonia in an otherwise healthy young patient. Patients aged >50 years are automatically classified as risk class 2, even if they have no additional risk criteria.
It is recommended that clinicians consider sepsis in patients with pneumonia. The PSI was developed prior to aggressive sepsis screening with lactate testing. For patients scoring high on the PSI, it would be prudent to ensure that initial triage has not missed the presence of sepsis. Evaluation for systemic inflammatory response syndrome criteria would be beneficial for these patients.
Clinicians should assess potential barriers to treatment such as vomiting, alcohol or drug use, psychosocial conditions, or cognitive impairments, even if a patient is categorized by PSI as appropriate for outpatient treatment.
While pneumonia is often viral in nature, typical practice is to provide a course of antibiotics because the pneumonia could be bacterial. Disposition (inpatient vs outpatient) often dictates further care and management, including laboratory testing and blood cultures.
Sagar Patel, MD
The original PSI study created a 5-tier risk stratification based on 14,199 inpatients with community-acquired pneumonia. Subsequent studies validated the PSI on 38,039 inpatients, and then on an additional 2287 inpatients and outpatients. The PSI assigns points based on age, comorbid disease, abnormal physical findings, and abnormal laboratory test results.
The PSI and the CURB-65 score offer equal sensitivity for mortality prediction in community-acquired pneumonia, but the CURB-65 score has a higher specificity (74.6%) than the PSI (52.2%). How-ever, the CURB-65 score had a lower sensitivity than the PSI for predicting intensive care unit admission.
Michael J. Fine, MD, MSc
Original/Primary Reference
Validation Reference
Additional Reference
The SMART-COP score predicts the need for intensive respiratory or vasopressor support in community-acquired pneumonia.
The SMART-COP score for pneumonia severity was developed to identify patients at increased risk for intensive respiratory or vasopressor support (IRVS). The score should be used for patients with community-acquired pneumonia (CAP) who may require intensive care unit (ICU) care. The tool does not estimate mortality and does not apply to patients with significant immunosuppression.
The SMART-COP score includes age-adjusted cutoffs for respiratory rate and oxygen levels, but otherwise does not explicitly include patient age as a variable, in contrast with the PSI and the CURB- 65 score. This may preserve the positive predictive value with advancing age.
CAP is the single most common cause of sepsis in older patients, but can be difficult to recognize due to blunted fever and tachycardic responses to infection in these patients. Consideration of other variables not included in the SMART-COP score, such as comorbidities, functional status, frailty, and clinician gestalt, may still result in a recommendation for ICU admission.
The SMART-COP score uses readily available patient information. It can help identify which patients need ICU admission, with 92.3% sensitivity, 62.3% specificity, and an area under the curve (AUC) of 0.87, leading to better utilization of resources and treatment initiation. Delayed admission to the ICU is associated with higher 30-day mortality rates in patients with CAP (Restrepo 2010). SMART-COP performs comparably with the minor criteria for severe CAP recommended by the 2007 Infectious Diseases Society of America/American Thoracic Society consensus guidelines.
Patients who do not meet criteria for ICU admission using the SMART-COP score should still be evaluated for the need for inpatient admission. They should also receive timely and appropriate empiric antibiotics for CAP, generally a beta-lactam plus a macrolide, or a fluoroquinolone. Goals of care and other variables may recommend against ICU admission even if the SMART-COP score is high.
For patients with high SMART-COP scores, clinicians should consider broadening the antibiotic regimen to include methicillin-resistant Staphylococcus aureus coverage (for ICU admission, necrotizing or cavitary infiltrates, or empyema, or previous methicillin-resistant Staphylococcus aureus infection) and/or to include antipseudomonal coverage (for history of structural lung disease, immunocompromise, or previous Pseudomonas aeruginosa infection). Clinicians should also be aware of the risk for associated sepsis and treat accordingly.
Jennifer Chen, MD, MPH
The original SMART-COP study published by Charles et al in 2008 prospectively examined patients with CAP at 6 hospitals in Australia over a 28-month period. It included 865 CAP episodes, with a mean patient age of 65.1 years. The SMART-COP score was developed to stratify patients into need for ICU admission based on risk for IRVS.
The study cohort had a 13.4% ICU admission rate, a 10.3% IRVS rate, and a 5.7% 30-day mortality rate. In the derivation study, the SMART-COP score demonstrated 92.3% sensitivity and 62.3% specificity (AUC = 0.87) for accurately predicting the need for IRVS, compared with 73.6% sensitivity for PSI classes IV and V, and compared with 38.5% sensitivity for CURB-65 group 3 patients.
The original study also validated the SMART-COP score using 5 existing databases (including the PORT database) with a total of 7464 patients. When applied to these 5 external databases, the SMART-COP score had an AUC of 0.72 to 0.87.
One database analysis study found that among hospitalized Medicare patients with pneumonia, ICU admission of patients for whom the admission decision appeared to be discretionary was associated with a 5.7% absolute survival advantage at 30 days compared with patients admitted to general wards (Valley 2015).
Patrick Charles, MBBS, FRACP, PhD
Original/Primary Reference
Validation Reference
Additional References
The DRIP score predicts risk for community-acquired pneumonia due to drug-resistant pathogens.
The drug resistance in pneumonia (DRIP) score should be used for patients who have community-acquired pneumonia with a bacterial cause. The goal of the DRIP score is to determine when broad-spectrum antibiotics should be used, both to determine effective treatment and to avoid increasing antibiotic resistance. A patient with a DRIP score <4 can be treated effectively without broad-spectrum antibiotic coverage, while a patient with a score ≥4 is more likely to require broad- spectrum antibiotic coverage.
False negatives on the DRIP score can occur in the following situations: methicillin-resistant Staphylococcus aureus or P aeruginosa infection; severe chronic obstructive pulmonary disease (requiring oxygen and steroids); intravenous drug use; psychiatric conditions; and homelessness. False positives can occur with S pneumoniae and methicillin-susceptible Staphylococcus aureus.
The DRIP score is more predictive than the healthcare-associated pneumonia (HCAP) criteria for drug-resistant pathogens, and may have the potential to decrease antibiotic overutilization in pneumonia. At a cutoff of ≥4 points, the DRIP score optimally differentiates high and low risk for drug-resistant pneumonia, supporting the utility of the score as a clinical decision tool to guide empiric antibiotic selection (Webb 2019).
John Dayton, MD
Webb et al created the DRIP score with a 2016 study that both derived and validated a clinical prediction tool to help predict which cases of bacterial pneumonia may be antibiotic resistant. Their research goal was to create a predictive score that would be more accurate than HCAP criteria. During the derivation portion of the study, multiple risk factors for drug-resistant pathogens were evaluated using logistic regression, for a cohort of 200 cases of confirmed bacterial pneumonia.
In the original study, the DRIP score was found to be more sensitive (82% vs 79%) and more specific (81% vs 65%) than HCAP criteria. It decreased use of unnecessary extended-spectrum antibiotics by 46% as compared to HCAP criteria.
A 2019 validation study by the original study authors found that the DRIP score decreased the use of unnecessary extended-spectrum antibiotics by 38% as compared with HCAP criteria. The study evaluated a broader set of risk factors than the HCAP definition. It reaffirmed that antibiotic use and hospitalization 60 days prior are major contributors to drug resistance, but did not find a strong association between severity of illness and drug resistance. The DRIP score was also found to be more specific and more accurate than 8 other predictive models, including the Shorr score.
Brandon Webb, MD
Original/Primary Reference
Validation References
Matthew DeLaney, MD, FACEP, FAAEM; Charles Khoury, MD, MSHA, FACEP
Daniel J. Egan, MD; Benjamin Christian Renne, MD
February 1, 2021
February 1, 2024   CME Information
4 AMA PRA Category 1 Credits™, 4 ACEP Category I Credits, 4 AAFP Prescribed Credits, 4 AOA Category 2-A or 2-B Credits. Specialty CME Credits: Included as part of the 4 credits, this CME activity is eligible for 4 Infectious Disease CME credits
Price: $59
+4 Credits!
Matthew DeLaney, MD, FACEP, FAAEM; Charles Khoury, MD, MSHA, FACEP
Daniel J. Egan, MD; Benjamin Christian Renne, MD
February 1, 2021
February 1, 2024
4 AMA PRA Category 1 Credits™, 4 ACEP Category I Credits, 4 AAFP Prescribed Credits, 4 AOA Category 2-A or 2-B Credits. Specialty CME Credits: Included as part of the 4 credits, this CME activity is eligible for 4 Infectious Disease CME credits
Evaluation and Management of Patients With Pharyngitis in Urgent Care
Fever in Children Aged 3 to 36 Months: Management in the Emergency Department (Pharmacology CME)
Urgent Care Diagnosis and Management of Urinary Tract Infections in Adults
Pediatric Influenza in the Emergency Department: Diagnosis and Management (Infectious Disease CME)