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The impact of upcoding, cream skimming and readmissions on hospitals’ efficiency: the case of Lombardy


  • Paolo Berta
  • Giuditta Callea


  • Gianmaria Martini
  • Giorgio Vittadini


This paper investigates the efficiency of Italian hospitals during the period 1998–2007 and consider the impact of some DRG distortions like uocoding, cream skimming and readmission. We apply both a stochastic frontier approach and a multilevel model. We show that readmissions are the most relevant distortion. Moreover, cream skimming has a negative impact for public and private hospitals and upcoding has a clear positive but little impact only for public hospitals. These results imply that the reaction of the different hospital types to the public policy aimed to reduced the DRG distortions is different. Private hospitals tend to reduce the DRGs while the public hospitals increase the readmissions. Last, private hospitals are less efficient than public and not–for–profit ones, once we take the DRG distortions (and other covariates) into account, both for the SF approach and the ML model.

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  • Paolo Berta & Giuditta Callea & Gianmaria Martini & Giorgio Vittadini, 2008. "The impact of upcoding, cream skimming and readmissions on hospitals’ efficiency: the case of Lombardy," Working Papers 0806, Department of Economics and Technology Management, University of Bergamo.
  • Handle: RePEc:brh:wpaper:0806

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    References listed on IDEAS

    1. Suzanne McCoskey & Chihwa Kao, 1998. "A residual-based test of the null of cointegration in panel data," Econometric Reviews, Taylor & Francis Journals, vol. 17(1), pages 57-84.
    2. Tuomo Vuolteenaho, 2002. "What Drives Firm-Level Stock Returns?," Journal of Finance, American Finance Association, vol. 57(1), pages 233-264, February.
    3. Hashem Pesaran, M., 2003. "Aggregation of linear dynamic models: an application to life-cycle consumption models under habit formation," Economic Modelling, Elsevier, vol. 20(2), pages 383-415, March.
    4. Peter C. B. Phillips & Hyungsik R. Moon, 1999. "Linear Regression Limit Theory for Nonstationary Panel Data," Econometrica, Econometric Society, vol. 67(5), pages 1057-1112, September.
    5. Stoker, Thomas M, 1993. "Empirical Approaches to the Problem of Aggregation Over Individuals," Journal of Economic Literature, American Economic Association, vol. 31(4), pages 1827-1874, December.
    6. Park, Joon Y. & Phillips, Peter C.B., 1999. "Asymptotics For Nonlinear Transformations Of Integrated Time Series," Econometric Theory, Cambridge University Press, vol. 15(03), pages 269-298, June.
    7. Campbell, John Y & Shiller, Robert J, 1987. "Cointegration and Tests of Present Value Models," Journal of Political Economy, University of Chicago Press, vol. 95(5), pages 1062-1088, October.
    8. Yoosoon Chang & Joon Y. Park, 2003. "A Sieve Bootstrap For The Test Of A Unit Root," Journal of Time Series Analysis, Wiley Blackwell, vol. 24(4), pages 379-400, July.
    9. Kwiatkowski, Denis & Phillips, Peter C. B. & Schmidt, Peter & Shin, Yongcheol, 1992. "Testing the null hypothesis of stationarity against the alternative of a unit root : How sure are we that economic time series have a unit root?," Journal of Econometrics, Elsevier, vol. 54(1-3), pages 159-178.
    10. Yan Shen & Cheng Hsiao & Hiroshi Fujiki, 2005. "Aggregate vs. disaggregate data analysis-a paradox in the estimation of a money demand function of Japan under the low interest rate policy," Journal of Applied Econometrics, John Wiley & Sons, Ltd., vol. 20(5), pages 579-601.
    11. Evan Gatev & William N. Goetzmann & K. Geert Rouwenhorst, 2006. "Pairs Trading: Performance of a Relative-Value Arbitrage Rule," Review of Financial Studies, Society for Financial Studies, vol. 19(3), pages 797-827.
    12. Forni, Mario & Lippi, Marco, 1997. "Aggregation and the Microfoundations of Dynamic Macroeconomics," OUP Catalogue, Oxford University Press, number 9780198288008, June.
    13. Pesaran, M. Hashem & Smith, Ron, 1995. "Estimating long-run relationships from dynamic heterogeneous panels," Journal of Econometrics, Elsevier, vol. 68(1), pages 79-113, July.
    14. Park, Joon Y. & Phillips, Peter C.B., 1988. "Statistical Inference in Regressions with Integrated Processes: Part 1," Econometric Theory, Cambridge University Press, vol. 4(03), pages 468-497, December.
    15. Lazarov , tep na & Trapani, Lorenzo & Urga, Giovanni, 2007. "Common Stochastic Trends And Aggregation In Heterogeneous Panels," Econometric Theory, Cambridge University Press, vol. 23(01), pages 89-105, February.
    16. Granger, C. W. J., 1993. "Implications of seeing economic variables through an aggregation window," Ricerche Economiche, Elsevier, vol. 47(3), pages 269-279, September.
    17. Chang, Yoosoon & Park, Joon Y. & Song, Kevin, 2006. "Bootstrapping cointegrating regressions," Journal of Econometrics, Elsevier, vol. 133(2), pages 703-739, August.
    18. Bai, Jushan, 2004. "Estimating cross-section common stochastic trends in nonstationary panel data," Journal of Econometrics, Elsevier, vol. 122(1), pages 137-183, September.
    19. Forni, Mario & Lippi, Marco, 1999. "Aggregation of linear dynamic microeconomic models," Journal of Mathematical Economics, Elsevier, vol. 31(1), pages 131-158, February.
    20. Gonzalo, Jesus, 1993. "Cointegration and aggregation," Ricerche Economiche, Elsevier, vol. 47(3), pages 281-291, September.
    21. Phillips, P.C.B., 1986. "Understanding spurious regressions in econometrics," Journal of Econometrics, Elsevier, vol. 33(3), pages 311-340, December.
    22. Lippi, Marco, 1988. "On the dynamic shape of aggregated error correction models," Journal of Economic Dynamics and Control, Elsevier, vol. 12(2-3), pages 561-585.
    23. Park, Joon Y., 2002. "An Invariance Principle For Sieve Bootstrap In Time Series," Econometric Theory, Cambridge University Press, vol. 18(02), pages 469-490, April.
    24. Kao, Chihwa, 1999. "Spurious regression and residual-based tests for cointegration in panel data," Journal of Econometrics, Elsevier, vol. 90(1), pages 1-44, May.
    25. Yoosoon Chang & Joon Park, 2002. "On The Asymptotics Of Adf Tests For Unit Roots," Econometric Reviews, Taylor & Francis Journals, vol. 21(4), pages 431-447.
    26. Shin, Yongcheol, 1994. "A Residual-Based Test of the Null of Cointegration Against the Alternative of No Cointegration," Econometric Theory, Cambridge University Press, vol. 10(01), pages 91-115, March.
    27. Xiao, Zhijie, 1999. "A residual based test for the null hypothesis of cointegration," Economics Letters, Elsevier, vol. 64(2), pages 133-141, August.
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    More about this item


    DRG distortions; hospital efficiency; ownership forms; stochastic frontier; multi level.;

    JEL classification:

    • I11 - Health, Education, and Welfare - - Health - - - Analysis of Health Care Markets
    • I18 - Health, Education, and Welfare - - Health - - - Government Policy; Regulation; Public Health
    • L33 - Industrial Organization - - Nonprofit Organizations and Public Enterprise - - - Comparison of Public and Private Enterprise and Nonprofit Institutions; Privatization; Contracting Out


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