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Has payment by results affected the way that English hospitals provide care? Difference-in-differences analysis

BMJ 2009; 339 doi: (Published 27 August 2009) Cite this as: BMJ 2009;339:b3047
  1. Shelley Farrar, research fellow1,
  2. Deokhee Yi, research fellow1,
  3. Matt Sutton, professor in health economics2,
  4. Martin Chalkley, professor3,
  5. Jon Sussex, deputy director4,
  6. Anthony Scott, professorial research fellow5
  1. 1Health Economics Research Unit, University of Aberdeen, Aberdeen AB25 2ZD
  2. 2Health Methodology Research Group, University of Manchester, Manchester M13 9PL
  3. 3Department of Economic Studies, University of Dundee, Dundee DD1 4HN
  4. 4Office of Health Economics, London SW1A 2DY
  5. 5Melbourne Institute of Applied Economic and Social Research, University of Melbourne, Parkville, Vic 3010, Australia
  1. Correspondence to: S Farrar s.farrar{at}
  • Accepted 17 May 2009


Objective To examine whether the introduction of payment by results (a fixed tariff case mix based payment system) was associated with changes in key outcome variables measuring volume, cost, and quality of care between 2003/4 and 2005/6.

Setting Acute care hospitals in England.

Design Difference-in-differences analysis (using a control group created from trusts in England and providers in Scotland not implementing payment by results in the relevant years); retrospective analysis of patient level secondary data with fixed effects models.

Data sources English hospital episode statistics and Scottish morbidity records for 2002/3 to 2005/6.

Main outcome measures Changes in length of stay and proportion of day case admissions as a proxy for unit cost; growth in number of spells to measure increases in output; and changes in in-hospital mortality, 30 day post-surgical mortality, and emergency readmission after treatment for hip fracture as measures of impact on quality of care.

Results Length of stay fell more quickly and the proportion of day cases increased more quickly where payment by results was implemented, suggesting a reduction in the unit costs of care associated with payment by results. Some evidence of an association between the introduction of payment by results and growth in acute hospital activity was found. Little measurable change occurred in the quality of care indicators used in this study that can be attributed to the introduction of payment by results.

Conclusion Reductions in unit costs may have been achieved without detrimental impact on the quality of care, at least in as far as these are measured by the proxy variables used in this study.


  • Contributors: SF conceived and led the study and drafted and finished the paper. DY prepared the database, did the econometric analysis, and contributed to writing the paper. MS contributed to the design, oversaw the econometric analysis, and contributed to writing the paper. MC contributed to the design of the study and the writing of the paper. JS advised on the analysis and contributed to writing of the paper. AS advised on the design of the study and contributed to the analysis and the writing of the paper. SF is the guarantor.

  • Funding: This research was funded by the Department of Health through the Policy Research Programme. The researchers are independent of the funders. The views expressed in this paper are those of the authors and not the funding body.

  • Competing interests: None declared.

  • Ethical approval: Not needed.

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