Health Policy 61 (2002) 21–42 Predicting the cost of hospital stay for stroke patients: the use of diagnosis related groups  Silvia Evers a,b, *, Gemma Voss c , Fred Nieman c , Andre ´ Ament a , Tom Groot d , Jan Lodder e , Anita Boreas e , Gerhard Blaauw b a Department of Health Organization Policy and Economics, Maastricht Uniersity, P.O. Box 616, 6200 MD Maastricht, The Netherlands b Department of Neurosurgery, Uniersity Hospital Maastricht, Maastricht, The Netherlands c Department of Clinical Epidemiology and Medical Technology Assessment, Uniersity Hospital Maastricht, Maastricht, The Netherlands d Department of Accounting, Vrije Uniersiteit Amsterdam, Amsterdam, The Netherlands e Department of Neurology, Uniersity Hospital Maastricht, Maastricht, The Netherlands Received 27 January 2001; accepted 19 September 2001 Abstract In order to provide tailor-made care, governments are considering the implementation of output-pricing based on hospital case-mix measures, such as diagnosis related groups (DRG). The question is whether the current DRG classification system can provide a satisfactory prediction of the variance of costs in stroke patients and if not, in what way other variables may enhance this prediction. In this study, data from 731 stroke patients hospitalized at University Hospital Maastricht during 1996 – 1998 are used in the cost analysis. The DRG classification for this group uses information — in addition to the DRG classification operation or no operation — on the patient’s age combined with discharge status. The results of regression analysis show that using DRGs, the variance explained in the costs amounts to 34%. Adding other variables to the DRGs, the variance explained increases to about 61%. Additional factors highly correlating with inpatient costs are the www.elsevier.com/locate/healthpol Abbreiations: CNS, Canadian neurological scale; DRG, diagnosis related group; EM, eye and motor scale; LOS, length of stay; MDC, major diagnosis categories; MSR, Maastricht stroke registry; PPS, prospective payment system; TIA, transient ischaemic attack.  This paper was presented at the Annual Meeting of the International Society for Technology Assessment in Health Care in The Hague, the Netherlands, June 18–21, 2000. * Corresponding author. Tel.: +31-43-388-1727; fax: +31-43-367-0960. E-mail address: s.evers@beoz.unimaas.nl (S. Evers). 0168-8510/02/$ - see front matter © 2002 Elsevier Science Ireland Ltd. All rights reserved. PII: S0168-8510(01)00219-6