PMCCPMCCPMCC

Search tips
Search criteria 

Advanced

 
Logo of hsresearchLink to Publisher's site
 
Health Serv Res. 1994 April; 29(1): 95–112.
PMCID: PMC1069990

The effect of alternative case-mix adjustments on mortality differences between municipal and voluntary hospitals in New York City.

Abstract

OBJECTIVE. This study investigated how mortality differences between groups of municipal versus voluntary hospitals are affected by case-mix adjustment methods. DATA SOURCES AND STUDY SETTING. We sampled about 10,000 random admissions from administrative data for patients hospitalized with each of six conditions in hospitals in New York City during 1984-1987. STUDY DESIGN. We developed logistic regression models adjusting for age and gender, for principal diagnosis, for "limited other diagnoses" (secondary diagnoses that were very unlikely to result from care received), for "full other diagnoses" (all secondary diagnoses irrespective of whether they might have been due to care received), for previous diagnoses, and for other variables. PRINCIPAL FINDINGS. For five of the six conditions, when the limited other diagnoses adjustment was used there was higher mortality in the municipal hospitals (p < .05), with 3.3 additional deaths/100 admissions for myocardial infarction, 1.2 for pneumonia, 8.3 for stroke, 2.8 for head trauma, and 0.8 for hip repair. However, when the full other diagnoses adjustment was used, differences remained significant only for stroke (4.3 additional deaths/100 admissions) and head trauma (1.3) (p < .05). CONCLUSIONS. Estimates of mortality differences between New York City municipal and voluntary hospitals are substantially affected by which secondary diagnoses are used in case-mix adjustment. Judgments of quality should not be based on administrative data unless models can be developed that validly capture level of sickness at admission.

Full text

Full text is available as a scanned copy of the original print version. Get a printable copy (PDF file) of the complete article (1.6M), or click on a page image below to browse page by page. Links to PubMed are also available for Selected References.

Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • Burstin HR, Lipsitz SR, Brennan TA. Socioeconomic status and risk for substandard medical care. JAMA. 1992 Nov 4;268(17):2383–2387. [PubMed]
  • DesHarnais SI, McMahon LF, Jr, Wroblewski RT, Hogan AJ. Measuring hospital performance. The development and validation of risk-adjusted indexes of mortality, readmissions, and complications. Med Care. 1990 Dec;28(12):1127–1141. [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]
  • Flood AB, Scott WR, Ewy W. Does practice make perfect? Part I: The relation between hospital volume and outcomes for selected diagnostic categories. Med Care. 1984 Feb;22(2):98–114. [PubMed]
  • Flood AB, Scott WR, Ewy W. Does practice make perfect? Part II: The relation between volume and outcomes and other hospital characteristics. Med Care. 1984 Feb;22(2):115–125. [PubMed]
  • Green J, Wintfeld N, Sharkey P, Passman LJ. The importance of severity of illness in assessing hospital mortality. JAMA. 1990 Jan 12;263(2):241–246. [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]
  • Hannan EL, O'Donnell JF, Kilburn H, Jr, Bernard HR, Yazici A. Investigation of the relationship between volume and mortality for surgical procedures performed in New York State hospitals. JAMA. 1989 Jul 28;262(4):503–510. [PubMed]
  • Iezzoni LI, Burnside S, Sickles L, Moskowitz MA, Sawitz E, Levine PA. Coding of acute myocardial infarction. Clinical and policy implications. Ann Intern Med. 1988 Nov 1;109(9):745–751. [PubMed]
  • Jencks SF, Daley J, Draper D, Thomas N, Lenhart G, Walker J. Interpreting hospital mortality data. The role of clinical risk adjustment. JAMA. 1988 Dec 23;260(24):3611–3616. [PubMed]
  • Kahn KL, Rogers WH, Rubenstein LV, Sherwood MJ, Reinisch EJ, Keeler EB, Draper D, Kosecoff J, Brook RH. Measuring quality of care with explicit process criteria before and after implementation of the DRG-based prospective payment system. JAMA. 1990 Oct 17;264(15):1969–1973. [PubMed]
  • Keeler EB, Kahn KL, Draper D, Sherwood MJ, Rubenstein LV, Reinisch EJ, Kosecoff J, Brook RH. Changes in sickness at admission following the introduction of the prospective payment system. JAMA. 1990 Oct 17;264(15):1962–1968. [PubMed]
  • Luft HS, Bunker JP, Enthoven AC. Should operations be regionalized? The empirical relation between surgical volume and mortality. N Engl J Med. 1979 Dec 20;301(25):1364–1369. [PubMed]
  • Park RE, Brook RH, Kosecoff J, Keesey J, Rubenstein L, Keeler E, Kahn KL, Rogers WH, Chassin MR. Explaining variations in hospital death rates. Randomness, severity of illness, quality of care. JAMA. 1990 Jul 25;264(4):484–490. [PubMed]
  • Pollack MM, Ruttimann UE, Getson PR. Accurate prediction of the outcome of pediatric intensive care. A new quantitative method. N Engl J Med. 1987 Jan 15;316(3):134–139. [PubMed]
  • Riley G, Lubitz J. Outcomes of surgery among the Medicare aged: surgical volume and mortality. Health Care Financ Rev. 1985 Fall;7(1):37–47. [PubMed]
  • Rubenstein LV, Kahn KL, Reinisch EJ, Sherwood MJ, Rogers WH, Kamberg C, Draper D, Brook RH. Changes in quality of care for five diseases measured by implicit review, 1981 to 1986. JAMA. 1990 Oct 17;264(15):1974–1979. [PubMed]

Articles from Health Services Research are provided here courtesy of Health Research & Educational Trust