Intensive Care Medicine

, 37:1409 | Cite as

Severity assessment tools to guide ICU admission in community-acquired pneumonia: systematic review and meta-analysis

  • James D. Chalmers
  • Pallavi Mandal
  • Aran Singanayagam
  • Ahsan R. Akram
  • Gourab Choudhury
  • Philip M. Short
  • Adam T. Hill



The aim of this meta-analysis was to determine if severity assessment tools can be used to guide decisions regarding intensive care unit (ICU) admission of patients with community-acquired pneumonia.


A search of PUBMED and EMBASE (1980–2009) was conducted to identify studies reporting pneumonia severity scores and prediction of ICU admission. Two reviewers independently collected data and assessed study quality. Performance characteristics were pooled using a random-effects model.


Sufficient data were collected to perform a meta-analysis on five current scoring systems: the Pneumonia Severity Index (PSI), the CURB65 score, the CRB65 score, the American Thoracic Society (ATS) 2001 criteria and the Infectious Disease Society of America/ATS (IDSA/ATS) 2007 criteria. The analysis was limited due to large variations in the ICU admission criteria, ICU admission rates and patient characteristics between different studies and different healthcare systems. In the pooled analysis, PSI, CURB65 and CRB65 performed similarly in terms of sensitivity and specificity across a range of cut-offs. Patients in CURB65 group 0 were at lowest risk of ICU admission (negative likelihood ratio 0.14; 95% confidence interval 0.06–0.34) while the ATS 2001 criteria had the highest positive likelihood ratio (7.05; 95% confidence interval 4.39–11.3).


Large variations exist in the use of ICU resources between different studies and different healthcare systems. Scoring systems designed to predict 30-day mortality perform less well when ICU admission is taken into account. Further studies of dedicated ICU admission scores are required.


Intensive care unit Meta-analysis Pneumonia Severity assessment 



American Thoracic Society


Community-acquired pneumonia


Chronic obstructive pulmonary disease


Confusion, respiratory rate, blood pressure, age ≥65 years


Confusion, urea, respiratory rate, blood pressure and age ≥65 years


Diagnostic odds ratio


Intensive care unit


Infectious Disease Society of America/American Thoracic Society


Negative likelihood ratio


Partial pressure of oxygen divided by the fraction of inspired oxygen


Positive likelihood ratio


Pneumonia Severity Index


Conflict of interest

All of the authors declare they have no conflicts of interest.

Supplementary material

134_2011_2261_MOESM1_ESM.doc (960 kb)
Supplementary material 1 (DOC 961 kb)


  1. 1.
    Mandell LA, Wunderink RG, Anzueto A, Bartlett JG, Campbell GD, Dean NC, Dowell SF, File TM Jr, Musher DM, Niederman MS, Torres A, Whitney CG, Infectious Diseases Society of America, American Thoracic Society (2007) Infectious Disease Society of American/American Thoracic Society Consensus Guidelines for the Management of Community Acquired Pneumonia in Adults. Clin Infect Dis 44:S27–S72PubMedCrossRefGoogle Scholar
  2. 2.
    British Thoracic Society (2009) The British Thoracic Society guidelines for the management of community acquired pneumonia in adults. Update 2009. Thorax 64[Suppl 3]:iii1–iii55Google Scholar
  3. 3.
    Singanayagam A, Chalmers JD, Hill AT (2009) Severity assessment in community-acquired pneumonia. Q J Med 102:379–388Google Scholar
  4. 4.
    Restrepo MI, Mortensen EM, Rello J, Brody J, Anzueto A (2010) Late admission to the ICU in patients with community-acquired pneumonia is associated with increased mortality. Chest 137:552–557PubMedCrossRefGoogle Scholar
  5. 5.
    Niederman MS, Mandell LA, Anzueto A, Bass JB, Broughton WA, Campbell GD, Dean N, File T, Fine MJ, Gross PA, Martinez F, Marrie TJ, Plouffe JF, Ramirez J, Sarosi GA, Torres A, Wilson R, Yu VL, American Thoracic Society (2001) Guidelines for the management of adults with community-acquired pneumonia. Diagnosis, assessment of severity, antimicrobial therapy, and prevention. Am J Respir Crit Care Med 163:1730–1754PubMedGoogle Scholar
  6. 6.
    Lim WS, van der Eerden MM, Laing R, Boersma WG, Karalus N, Town GI, Lewis SA, Macfarlane JT (2003) Defining community-acquired pneumonia severity on presentation to hospital: an international derivation and validation study. Thorax 58:377–382PubMedCrossRefGoogle Scholar
  7. 7.
    Fine MJ, Auble TE, Yealy DM, Hanusa BH, Weissfeld LA, Singer DE, Coley CM, Marrie TJ, Kapoor WN (1997) A prediction rule to identify low-risk patients with community-acquired pneumonia. N Engl J Med 336:243–250PubMedCrossRefGoogle Scholar
  8. 8.
    Therapeutic Guidelines Writing Group (2003) Australian community acquired pneumonia guidelines. Version 12. Therapeutic Guidelines Ltd, MelbourneGoogle Scholar
  9. 9.
    Phua J, See KC, Chan YH, Widjaja LS, Aung NW, Ngerng WJ, Lim TK (2009) Validation and clinical implications of the IDSA/ATS minor criteria for severe community-acquired pneumonia. Thorax 64:598–603PubMedCrossRefGoogle Scholar
  10. 10.
    Chalmers JD, Singanayagam A, Hill AT (2008) Systolic blood pressure is superior to other haemodynamic predictors of outcome in community acquired pneumonia. Thorax 63:698–702PubMedCrossRefGoogle Scholar
  11. 11.
    Buising KL, Thursky KA, Robertson MB, Black JF, Street AC, Richards MJ, Brown GV (2006) A prospective comparison of severity scores for identifying patients with severe community-acquired pneumonia: reconsidering what is meant by severe pneumonia. Thorax 61:419–424PubMedCrossRefGoogle Scholar
  12. 12.
    Angus DC, Marrie TJ, Obrosky DS, Clermont G, Dremsizov TT, Coley C, Fine MJ, Singer DE, Kapoor WN (2002) Severe community acquired pneumonia. Use of Intensive Care Services and Evaluation of American and British Thoracic Society Diagnostic Criteria. Am J Respir Crit Care Med 166:717–723PubMedCrossRefGoogle Scholar
  13. 13.
    Yandiola PP, Capelastegui A, Quintana J, Diez R, Gorordo I, Bilbao A, Zalacain R, Menendez R, Torres A (2009) Prospective comparison of severity scores for predicting clinically relevant outcomes for patients hospitalized with community-acquired pneumonia. Chest 135:1572–1579PubMedCrossRefGoogle Scholar
  14. 14.
    Charles PG, Wolfe R, Whitby M, Fine MJ, Fuller AJ, Stirling R, Wright AA, Ramirez JA, Christiansen KJ, Waterer GW, Pierce RJ, Armstrong JG, Korman TM, Holmes P, Obrosky DS, Peyrani P, Johnson B, Hooy M, Australian Community-Acquired Pneumonia Study Collaboration, Grayson ML (2008) SMART-COP: a tool for predicting the need for intensive respiratory or vasopressor support in community-acquired pneumonia. Clin Infect Dis 47:375–384PubMedCrossRefGoogle Scholar
  15. 15.
    España PP, Capelastegui A, Gorordo I, Esteban C, Oribe M, Ortega M, Bilbao A, Quintana JM (2006) Development and validation of a clinical prediction rule for severe community-acquired pneumonia. Am J Respir Crit Care Med 174:1249–1256PubMedCrossRefGoogle Scholar
  16. 16.
    Chalmers JD (2009) ICU admission and severity assessment in community-acquired pneumonia. Crit Care 13:156PubMedCrossRefGoogle Scholar
  17. 17.
    Stroup DF, Berlin JA, Morton SC, Olkin I, Williamson GD, Rennie D, Moher D, Becker BJ, Sipe TA, Thacker SB (2000) Meta-analysis of observational studies in epidemiology. JAMA 283:2008–2012PubMedCrossRefGoogle Scholar
  18. 18.
    Hayden JA, Cote P, Bombardier C (2006) Evaluation of the quality of prognostic studies in systematic reviews. Ann Intern Med 144:427–437PubMedGoogle Scholar
  19. 19.
    Chalmers JD, Singanayagam A, Akram AR et al (2010) Severity assessment tools for predicting mortality in hospitalised patients with community acquired pneumonia. Thorax 65:878–883PubMedCrossRefGoogle Scholar
  20. 20.
    Deeks JJ, Altman DG (2004) Diagnostic tests 4: likelihood ratios. Br Med J 329:168–169CrossRefGoogle Scholar
  21. 21.
    Ewig S, Ruiz M, Mensa J, Marcos MA, Martinez JA, Arancibia F, Niederman MS, Torres A (1998) Severe community-acquired pneumonia. Assessment of severity criteria. Am J Respir Crit Care Med 158:1102–1108PubMedGoogle Scholar
  22. 22.
    Ewig S, Seifert K, Kleinfeld T, Göke N, Schäfer H (2000) Management of patients with community-acquired pneumonia in a primary care hospital: a critical evaluation. Respir Med 94:556–563PubMedCrossRefGoogle Scholar
  23. 23.
    Feagan BG, Marrie TJ, Lau CY, Wheeler SL, Wong CJ, Vandervoort MK (2000) Treatment and outcomes of community-acquired pneumonia at Canadian hospitals. Can Med Assoc J 162:1415–1420Google Scholar
  24. 24.
    Rosón B, Carratalà J, Dorca J, Casanova A, Manresa F, Gudiol F (2001) Etiology, reasons for hospitalization, risk classes and outcomes of community-acquired pneumonia in patients hospitalized on the basis of conventional admission criteria. Clin Infect Dis 33:158–165PubMedCrossRefGoogle Scholar
  25. 25.
    van der Eerden MM, de Graaff CS, Bronsveld W, Jansen HM, Boersma WG (2004) Prospective evaluation of pneumonia severity index in hospitalised patients with community-acquired pneumonia. Respir Med 98:872–878PubMedCrossRefGoogle Scholar
  26. 26.
    Lamy O, Van Melle G, Cornuz J, Burnand B (2004) Clinical management of immunocompetent hospitalized patients with community-acquired pneumonia. Eur J Intern Med 15:28–34PubMedCrossRefGoogle Scholar
  27. 27.
    Riley PD, Aronsky D, Dean NC (2004) Validation of the 2001 American Thoracic Society criteria for severe community-acquired pneumonia. Crit Care Med 32:2398–2402PubMedCrossRefGoogle Scholar
  28. 28.
    Ewig S, de Roux A, Bauer T, García E, Mensa J, Niederman M, Torres A (2004) Validation of predictive rules and indices of severity for community-acquired pneumonia. Thorax 59:421–427PubMedCrossRefGoogle Scholar
  29. 29.
    Capelastegui A, España PP, Quintana JM, Areitio I, Gorordo I, Egurrola M, Bilbao A (2006) Validation of a predictive rule for the management of community-acquired pneumonia. Eur Respir J 27:151–157PubMedCrossRefGoogle Scholar
  30. 30.
    Spindler C, Ortqvist A (2006) Prognostic score systems and community-acquired bacteraemic pneumococcal pneumonia. Eur Respir J 28:816–823PubMedCrossRefGoogle Scholar
  31. 31.
    Migliorati PL, Boccoli E, Bracci LS, Sestini P, Melani AS (2006) A survey on hospitalised community-acquired pneumonia. Monaldi Arch Chest Dis 65:82–88PubMedGoogle Scholar
  32. 32.
    Marrie TJ, Shariatzadeh MR (2007) Community-acquired pneumonia requiring admission to an intensive care unit: a descriptive study. Medicine (Baltimore) 86:103–111CrossRefGoogle Scholar
  33. 33.
    Man SY, Lee N, Ip M, Antonio GE, Chau SS, Mak P, Graham CA, Zhang M, Lui G, Chan PK, Ahuja AT, Hui DS, Sung JJ, Rainer TH (2007) Prospective comparison of three predictive rules for assessing severity of community-acquired pneumonia in Hong Kong. Thorax 62:348–353PubMedCrossRefGoogle Scholar
  34. 34.
    Renaud B, Coma E, Labarere J, Hayon J, Roy PM, Boureaux H, Moritz F, Cibien JF, Guérin T, Carré E, Lafontaine A, Bertrand MP, Santin A, Brun-Buisson C, Fine MJ, Roupie E, Pneumocom Study Investigators (2007a) Routine use of the pneumonia severity index for guiding the site-of-treatment decision of patients with pneumonia in the emergency department: a multicenter, prospective, observational, controlled cohort study. Clin Infect Dis 44:41–49PubMedCrossRefGoogle Scholar
  35. 35.
    Renaud B, Coma E, Hayon J, Gurgui M, Longo C, Blancher M, Jouannic I, Betoulle S, Roupie E, Fine MJ, PNEUMOCOM study investigators (2007b) Investigation of the ability of the Pneumonia Severity Index to accurately predict clinically relevant outcomes: a European study. Clin Microbiol Infect 13:923–931PubMedCrossRefGoogle Scholar
  36. 36.
    Etzion O, Novack V, Avnon L, Porath A, Dagan E, Riesenberg K, Avriel A, Schlaeffer F (2007) Characteristics of low-risk patients hospitalized with community-acquired pneumonia. Eur J Intern Med 18:209–214PubMedCrossRefGoogle Scholar
  37. 37.
    Restrepo MI, Mortensen EM, Velez JA, Frei C, Anzueto A (2008) A comparative study of community-acquired pneumonia patients admitted to the ward and the ICU. Chest 133:610–617PubMedCrossRefGoogle Scholar
  38. 38.
    Garau J, Baquero F, Pérez-Trallero E, Pérez JL, Martín-Sánchez AM, García-Rey C, Martín-Herrero JE, Dal-Ré R, NACER Group (2008) Factors impacting on length of stay and mortality of community-acquired pneumonia. Clin Microbiol Infect 14:322–329PubMedCrossRefGoogle Scholar
  39. 39.
    Ananda-Rajah MR, Charles PG, Melvani S, Burrell LL, Johnson PD, Grayson ML (2008) Comparing the pneumonia severity index with CURB-65 in patients admitted with community acquired pneumonia. Scand J Infect Dis 40:293–300PubMedCrossRefGoogle Scholar
  40. 40.
    Liapikou A, Ferrer M, Polverino E, Balasso V, Esperatti M, Piñer R, Mensa J, Luque N, Ewig S, Menendez R, Niederman MS, Torres A (2009) Severe community-acquired pneumonia: validation of the infectious diseases society of America/American Thoracic society guidelines to predict an intensive care unit admission. Clin Infect Dis 48:377–385PubMedCrossRefGoogle Scholar
  41. 41.
    Feldman C, Alanee S, Yu VL, Richards GA, Ortqvist A, Rello J, Chiou CC, Chedid MB, Wagener MM, Klugman KP, International Pneumococcal Study Group (2009) Severity of illness scoring systems in patients with bacteraemic pneumococcal pneumonia: implications for the intensive care unit care. Clin Microbiol Infect 15:850–857PubMedCrossRefGoogle Scholar
  42. 42.
    Kontou P, Kuti JL, Nicolau DP (2009) Validation of the Infectious Diseases Society of America/American Thoracic Society criteria to predict severe community-acquired pneumonia caused by Streptococcus pneumoniae. Am J Emerg Med 27:968–974PubMedCrossRefGoogle Scholar
  43. 43.
    Brown SM, Jones BE, Jephson AR, Dean NC (2009) Validation of the Infectious Disease Society of America/American Thoracic Society 2007 guidelines for severe community-acquired pneumonia. Crit Care Med 37:3010–3016PubMedCrossRefGoogle Scholar
  44. 44.
    Buising KL, Thursky KA, Black JF, MacGregor L, Street AC, Kennedy MP, Brown GV (2007) Identifying severe community-acquired pneumonia in the emergency department: a simple clinical prediction tool. Emerg Med Aust 19:418–426CrossRefGoogle Scholar
  45. 45.
    Renaud B, Labarère J, Coma E, Santin A, Hayon J, Gurgui M, Camus N, Roupie E, Hémery F, Hervé J, Salloum M, Fine MJ, Brun-Buisson C (2009) Risk stratification of early admission to the intensive care unit of patients with no major criteria of severe community-acquired pneumonia: development of an international prediction rule. Crit Care 13:R54PubMedCrossRefGoogle Scholar
  46. 46.
    Chalmers JD, Singanayagam A, Hill AT (2008) Predicting the need for mechanical ventilation and/or inotropic support for young adults admitted to the hospital with community-acquired pneumonia. Clin Infect Dis 47:1571–1574PubMedCrossRefGoogle Scholar
  47. 47.
    Charles PG, Davis JS, Grayson ML (2009) Rocket science and the infectious diseases society of American/American Thoracic Society (IDSA/ATS) guidelines for severe community-acquired pneumonia. Clin Infect Dis 48:1796PubMedCrossRefGoogle Scholar
  48. 48.
    Charles PG (2008) Predicting the need for ICU in community-acquired pneumonia. Chest 133:587PubMedCrossRefGoogle Scholar
  49. 49.
    Restrepo MI, Bienen T, Mortensen EM, Anzueto A, Metersky ML, Escalante P, Wunderink RG, Mangura BT, Chest Infections Network (2008) Evaluation of ICU admission criteria and diagnostic methods for patients with severe community-acquired pneumonia: current practice survey. Chest 133:828–829PubMedCrossRefGoogle Scholar
  50. 50.
    Buising KL, Thursky KA, Black JF, Brown GV (2004) Are the Australian guidelines asking too much of the Pneumonia Severity Index (PSI)? Med J Aust 180:486–487PubMedGoogle Scholar
  51. 51.
    Ewig S, Birkner N, Strauss R, Schaefer E, Pauletzki J, Bischoff H, Schraeder P, Welte T, Hoeffken G (2009) New perspectives on community-acquired pneumonia in 388,406 patients. Results from a nationwide mandatory performance measurement programme in healthcare quality. Thorax 64:1062–1069PubMedCrossRefGoogle Scholar
  52. 52.
    Marrie TJ, Fine MJ, Kapoor WN, Coley CM, Singer DE, Obrosky DS (2002) Community-acquired pneumonia and do not resuscitate orders. J Am Geriatr Soc 50:290–299PubMedCrossRefGoogle Scholar
  53. 53.
    Mortensen EM, Coley CM, Singer DE, Marrie TJ, Obrosky DS, Kapoor WN, Fine MJ (2002) Causes of death for patients with community-acquired pneumonia: results from the Pneumonia Patient Outcomes Research Team cohort study. Arch Intern Med 162:1059–1064PubMedCrossRefGoogle Scholar
  54. 54.
    Valencia M, Badia JR, Cavalcanti M, Ferrer M, Agustí C, Angrill J, García E, Mensa J, Niederman MS, Torres A (2007) Pneumonia severity index class V patients with community acquired pneumonia: characteristics, outcomes and value of severity scores. Chest 132:515–522PubMedCrossRefGoogle Scholar
  55. 55.
    Schuetz P, Koller M, Christ-Crain M, Steyerberg E, Stolz D, Müller C, Bucher HC, Bingisser R, Tamm M, Müller B (2008) Predicting mortality with pneumonia severity scores: importance of model recalibration to local settings. Epidemiol Infect 136:1628–1637PubMedCrossRefGoogle Scholar

Copyright information

© Copyright jointly held by Springer and ESICM 2011

Authors and Affiliations

  • James D. Chalmers
    • 1
    • 2
  • Pallavi Mandal
    • 2
  • Aran Singanayagam
    • 2
  • Ahsan R. Akram
    • 2
  • Gourab Choudhury
    • 2
  • Philip M. Short
    • 3
  • Adam T. Hill
    • 2
  1. 1.University of EdinburghEdinburghUK
  2. 2.Department of Respiratory MedicineRoyal Infirmary of EdinburghEdinburghUK
  3. 3.Ninewells HospitalDundeeUK

Personalised recommendations