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The European Journal of Health Economics

, Volume 13, Issue 3, pp 355–363 | Cite as

Association of antipsychotic polypharmacy with health service cost: a register-based cost analysis

  • Lone Baandrup
  • Jan Sørensen
  • Henrik Lublin
  • Merete Nordentoft
  • Birte Glenthoj
Original Paper

Abstract

Objective

To investigate the association of antipsychotic polypharmacy in schizophrenia with cost of primary and secondary health service use.

Method

Comparative analysis of health service cost for patients prescribed antipsychotic polypharmacy versus antipsychotic monotherapy. Resource utilisation and costs were described using central Danish registers for a 2 year period (2007–2008). We included patients attached to one of two Danish psychiatric referral centres in 1 January 2008 and/or 1 January 2009. Their prescribed treatment with either antipsychotic polypharmacy or monotherapy at the two cross-sectional dates was recorded and used as proxy of polypharmacy exposure during the preceding year. A multivariate generalised linear model was fitted with total costs of primary and secondary health service use as dependent variable, and antipsychotic polypharmacy, diagnosis, age, gender, disease duration, psychiatric inpatient admissions, and treatment site as covariates.

Results

The sample consisted of 736 outpatients with a diagnosis in the schizophrenia spectrum. Antipsychotic polypharmacy was associated with significantly higher total health service costs compared with monotherapy (2007: 25% higher costs; 2008: 17% higher costs) when adjusting for potential confounders and risk factors. A subgroup analysis suggested that the excessive costs associated with antipsychotic polypharmacy were partly accounted for by the functional level of the patients.

Conclusion

The results demonstrate that antipsychotic co-prescribing is associated with increased use of health care services, even though no causal relations can be inferred from an observational study.

Keywords

Schizophrenia Antipsychotic polypharmacy Health service cost 

JEL Classification

I120 

Notes

Acknowledgments

The study was supported by the National Board of Health in Denmark (0-204-02-9/9) as part of the funding for a health technology assessment, and the Wørzner Foundation.

Conflict of interest

The authors have no conflicts of interest to declare.

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Copyright information

© Springer-Verlag 2011

Authors and Affiliations

  • Lone Baandrup
    • 1
  • Jan Sørensen
    • 2
  • Henrik Lublin
    • 1
  • Merete Nordentoft
    • 3
  • Birte Glenthoj
    • 1
  1. 1.Centre for Neuropsychiatric Schizophrenia ResearchCopenhagen University Hospital, Mental Health Services - Capital Region of Denmark, GlostrupGlostrupDenmark
  2. 2.Centre for Applied Health Services Research and Technology AssessmentUniversity of Southern DenmarkOdenseDenmark
  3. 3.Copenhagen University Hospital, Mental Health Services - Capital Region of Denmark, BispebjergCopenhagen NVDenmark

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