Search tips
Search criteria 


Logo of hsresearchLink to Publisher's site
Health Serv Res. 1987 June; 22(2): 157–182.
PMCID: PMC1065430

The volume-outcome relationship: practice-makes-perfect or selective-referral patterns?


Various studies have demonstrated that hospitals with larger numbers of patients with a specific diagnosis or procedure have lower mortality rates. In some instances, these results have been interpreted to mean that physicians and hospital personnel with more of these patients develop greater skills and that this results in better outcomes--the "practice-makes-perfect" hypothesis. An alternative explanation is that physicians and hospitals with better outcomes attract more patients--the "selective-referral pattern" hypothesis. Using data for 17 categories of patients from a sample of over 900 hospitals, we examine the patterns of selected variables with respect to hospital volume. To explore the plausibility of each hypothesis, a simultaneous-equation model is also used to test the relative importance of the two explanations for each diagnosis or procedure. The results suggest that both explanations are valid, and that the relative importance of the practice or referral explanation varies by diagnosis or procedure, in ways consistent with clinical aspects of the various patient categories.

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 (2.2M), 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.
  • 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]
  • Maerki SC, Luft HS, Hunt SS. Selecting categories of patients for regionalization. Implications of the relationship between volume and outcome. Med Care. 1986 Feb;24(2):148–158. [PubMed]
  • Shortell SM, LoGerfo JP. Hospital medical staff organization and quality of care: results for myocardial infarction and appendectomy. Med Care. 1981 Oct;19(10):1041–1055. [PubMed]
  • Wolfe RA, Roi LD, Flora JD, Feller I, Cornell RG. Mortality differences and speed of wound closure among specialized burn care facilities. JAMA. 1983 Aug 12;250(6):763–766. [PubMed]
  • Farber BF, Kaiser DL, Wenzel RP. Relation between surgical volume and incidence of postoperative wound infection. N Engl J Med. 1981 Jul 23;305(4):200–204. [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]
  • Iglehart JK. Cutting costs of health care for the poor in California. A two-year follow-up. N Engl J Med. 1984 Sep 13;311(11):745–748. [PubMed]
  • Luft HS, Hunt SS. Evaluating individual hospital quality through outcome statistics. JAMA. 1986 May 23;255(20):2780–2784. [PubMed]
  • Luft HS. The relation between surgical volume and mortality: an exploration of causal factors and alternative models. Med Care. 1980 Sep;18(9):940–959. [PubMed]
  • Wennberg J, Gittelsohn A. Variations in medical care among small areas. Sci Am. 1982 Apr;246(4):120–134. [PubMed]
  • Roos NP. Hysterectomy: variations in rates across small areas and across physicians' practices. Am J Public Health. 1984 Apr;74(4):327–335. [PubMed]

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