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Health Serv Res. 1994 August; 29(3): 367–390.
PMCID: PMC1070010

PMC Patient Severity Scale: derivation and validation.


OBJECTIVE. This study describes the derivation and validation of the Patient Management Category (PMC) Severity Scale, which provides a method of assessing the overall severity of a hospitalized patient's illnesses, based on the patient's unique clinical conditions, their interaction, and the resultant, combined risk of morbidity and mortality. DATA SOURCES. Derivation of the PMC Severity Scale was based on clinical judgment together with empirical analysis of more than a half million patients discharged from acute care hospitals in Maryland during 1989. The scale was validated by using two distinct calendar years (1988 and 1990) of patients data from the same Maryland hospitals and a six-month patient database from California (1990). STUDY DESIGN. The PMC Severity Scale is an ordinal scale with seven levels: Level 7 represents the greatest likelihood of death and major disease burden. The scale quantifies the severity of each of the patient's disease(s) and accounts for the effect of all coexisting conditions and complications. DATA EXTRACTION METHODS. Publicly available, statewide all-payer claims databases were acquired from Maryland and California. PRINCIPAL FINDINGS. The independent relationships between the PMC Severity Scale with mortality and with length of stay are statistically different across severity levels within each population tested, but the relationships are statistically similar over time. Further, the PMC Severity Scale was determined to be a stable predictor of mortality and LOS across two diverse geographic regions. CONCLUSIONS. Since the severity of a patient's illness is one of the factors that influences the outcomes of care, the PMC Severity Scale can be used successfully as a risk adjustment tool in a variety of quality applications.

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Selected References

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  • Charbonneau C, Ostrowski C, Poehner ET, Lindsay P, Panniers TL, Houghton P, Albright J. Validity and reliability issues in alternative patient classification systems. Med Care. 1988 Aug;26(8):800–813. [PubMed]
  • Charlson ME, Pompei P, Ales KL, MacKenzie CR. A new method of classifying prognostic comorbidity in longitudinal studies: development and validation. J Chronic Dis. 1987;40(5):373–383. [PubMed]
  • Dubois RW, Rogers WH, Moxley JH, 3rd, Draper D, Brook RH. Hospital inpatient mortality. Is it a predictor of quality? N Engl J Med. 1987 Dec 24;317(26):1674–1680. [PubMed]
  • Gonnella JS, Hornbrook MC, Louis DZ. Staging of disease. A case-mix measurement. JAMA. 1984 Feb 3;251(5):637–644. [PubMed]
  • Greenfield S, Aronow HU, Elashoff RM, Watanabe D. Flaws in mortality data. The hazards of ignoring comorbid disease. JAMA. 1988 Oct 21;260(15):2253–2255. [PubMed]
  • Kelleher C. Relationship of physician ratings of severity of illness and difficulty of clinical management to length of stay. Health Serv Res. 1993 Feb;27(6):841–855. [PMC free article] [PubMed]
  • Stein RE, Gortmaker SL, Perrin EC, Perrin JM, Pless IB, Walker DK, Weitzman M. Severity of illness: concepts and measurements. Lancet. 1987 Dec 26;2(8574):1506–1509. [PubMed]
  • Thomas JW, Holloway JJ, Guire KE. Validating risk-adjusted mortality as an indicator for quality of care. Inquiry. 1993 Spring;30(1):6–22. [PubMed]
  • Young JC, Macioce DP, Young WW. Identifying injuries and trauma severity in large databases. J Trauma. 1990 Oct;30(10):1220–1230. [PubMed]
  • Young WW. Incorporating severity of illness and comorbidity in case-mix measurement. Health Care Financ Rev. 1984;Suppl:23–31. [PubMed]
  • Young WW, Young JC, Smith JS, Rhodes M. Defining the major trauma patient and trauma severity. J Trauma. 1991 Aug;31(8):1125–1141. [PubMed]

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