PharmacoEconomics

, Volume 20, Issue 1, pp 49–60

Economic Impact of Low Dose Polyethylene Glycol 3350 Plus Electrolytes Compared with Lactulose in the Management of Idiopathic Constipation in the UK

  • Angela H. Christie
  • Pearl Culbert
  • Julian F. Guest
Original Research Article

Abstract

Objective: To estimate the economic impact of using low dose 3350 (PEG 3350) plus electrolytes (PEG+E) compared with lactulose in the treatment of idiopathic constipation in ambulant patients.

Design and perspective: This was a decision analytic modelling study performed from the perspective of the UK’s National Health Service (NHS).

Methods: The clinical outcomes from a previously reported single-blind, randomised, multicentre trial were used as the clinical basis for the analysis. These data were combined with resource utilisation estimates derived from a panel of six general practitioners (GPs) and four nurses enabling a decision model to be constructed depicting the management of idiopathic constipation with either PEG+E or lactulose over 3 months. The model was used to estimate the expected 3-monthly NHS cost of using either laxative to manage idiopathic constipation.

Main outcome measures and results: The expected 3-monthly NHS cost of using PEG+E or lactulose to manage idiopathic constipation was estimated to be £85 and £96 per patient, respectively (1999/2000 values). However, significantly more patients were successfully treated with PEG+E than lactulose (53% versus 24%; p < 0.001) at 3 months. GP visits were the primary cost driver for both PEG+E- and lactulose-treated patients, accounting for 56% (2.9 visits) and 73% (4.4 visits), respectively, of the expected NHS cost per patient at 3 months. Among PEG+E-treated patients, the acquisition cost of PEG+E was the secondary cost driver, accounting for 30% of the expected NHS cost per patient at 3 months, whereas the acquisition cost of lactulose accounted for only 11% of the expected NHS cost per lactulose-treated patient. District nurse domiciliary visits accounted for 4% and thyroid function tests for 2%. The costs of switched laxatives, concomitant laxatives, and gastroenterologist and colorectal surgeon visits collectively accounted for up to 9% of the total.

Conclusions: The true cost of managing idiopathic constipation is impacted on by a broad range of resources and not only laxative acquisition costs. This study indicated that managing idiopathic constipation with PEG+E instead of lactulose reduces the expected 3-monthly NHS cost by £11 per patient. Moreover, using PEG+E instead of lactulose is expected to double the percentage of patients successfully treated at 3 months. Hence, PEG+E is a dominant treatment compared with lactulose. This suggests that the decision to use either PEG+E or lactulose to treat idiopathic constipation should be based on efficacy, safety, patient preferences and total management costs, and not drug acquisition costs.

References

  1. 1.
    Passmore A. Economic aspects of pharmacotherapy for chronic constipation. Pharmacoeconomics 1995; 7 (1): 14–24PubMedCrossRefGoogle Scholar
  2. 2.
    Barloon T, Lu C. Diagnostic imaging in the evaluation of constipation in adults. Am Fam Physician 1997; 56 (2): 513–20PubMedGoogle Scholar
  3. 3.
    Ross H. Constipation: cause and control in an acute hospital setting. Br J Nurs 1998; 7 (15): 907–13PubMedGoogle Scholar
  4. 4.
    Powell M, Davies C. Constipation: a management overview. Audit of chronic constipation in the community. London: Professional Medical Communications Ltd, 1999Google Scholar
  5. 5.
    Kinnunen O, Winblad I, Koistinen P, et al. Safety and efficacy of a bulk laxative containing senna versus lactulose in the treatment of chronic constipation in geriatric patients. Pharmacology 1993; 47 Suppl. 1: 253–5PubMedCrossRefGoogle Scholar
  6. 6.
    Rantis P, Vernava A, Daniel G, et al. Chronic constipation: is the work up worth the cost? Dis Colon Rectum 1997; 40 (3): 280–6PubMedCrossRefGoogle Scholar
  7. 7.
    Stark M. Challenging problems presenting as constipation. Am J Gastroenterol 1999; 94 (3): 567–74PubMedCrossRefGoogle Scholar
  8. 8.
    Barbara L, Corindalesi R, Gizzi G, et al. Food, fibre and bowel function. In: Barbara L, Corindalesi R, Gizzi G, et al., editors. Chronic constipation. United Kingdom:W.B. Saunders & Co Ltd, 1996: 79–92Google Scholar
  9. 9.
    Brandt LJ. Constipation, megacolon and fecal impaction. In: Brandt LJ, editor. Clinical practice of gastroenterology. Vol. 1. Churchill Livingstone, 1999: 633–4Google Scholar
  10. 10.
    Tedesco F, DiPiro J. Laxative use in constipation. Am J Gastroenterol 1985; 80 (4): 303–9PubMedGoogle Scholar
  11. 11.
    Colley W. Constipation-2 treatment. Nurs Times 1999; 95 (21): S1–2Google Scholar
  12. 12.
    Attar A, Lémann M, Ferguson A, et al. Comparison of a low dose polyethylene glycol electrolyte solution with lactulose for treatment of chronic constipation. Gut 1999; 44: 226–30PubMedCrossRefGoogle Scholar
  13. 13.
    Netten A, Dennett J, Knight J. Unit costs of health and social care 1999. Canterbury: University of Kent, Personal Social Services Research Unit, 1999.Google Scholar
  14. 14.
    Monthly index of medical specialities, 2000 editions. London: Haymarket Publications Ltd, 2000Google Scholar
  15. 15.
    Tramonte S, Brand M, Mulrow C, et al. The treatment of chronic constipation in adults: a systematic review. J Gen Int Med 1997; 12: 15–24CrossRefGoogle Scholar
  16. 16.
    The management of constipation. MeReC Bull 1999; 10 (9): 33–6Google Scholar
  17. 17.
    Lederle F. Epidemiology of constipation in elderly patients: drug utilisation and cost-containment strategies. Drugs Aging 1995; 6 (6): 465–9PubMedCrossRefGoogle Scholar
  18. 18.
    Passmore A, Wilson-Davies K, Stoker C, et al. Chronic constipation in long stay elderly patients: a comparison of lactulose and a senna-fibre combination. BMJ 1993; 307: 769–71PubMedCrossRefGoogle Scholar
  19. 19.
    Morbidity statistics from general practice: fourth national study 1991–1992. London: Office for National StatisticsGoogle Scholar
  20. 20.
    Prescription cost analysis: England 1998. London; Department of Health, 1999Google Scholar
  21. 21.
    Avery A, Groom L, Brown K, et al. The impact of nursing home patients on prescribing costs in general practice. J Clin Pharm Ther 1999; 24: 357–63PubMedCrossRefGoogle Scholar
  22. 22.
    Poulton B, Thomas S. The nursing cost of constipation. RCN’s Continence Care Forum 1999. Primary Health Care 1999 Nov; 9 (9): 17–22Google Scholar
  23. 23.
    Frank L, Kleinman L, Farup L, et al. Psychometric validation of a constipation symptom assessment questionnaire. Scand J Gastroenterol 1999; 34: 870–7PubMedCrossRefGoogle Scholar

Copyright information

© Adis International Limited 2002

Authors and Affiliations

  • Angela H. Christie
    • 1
  • Pearl Culbert
    • 2
  • Julian F. Guest
    • 1
  1. 1.Catalyst Health Economics ConsultantsNorthwoodUK
  2. 2.Western General HospitalEdinburghUK

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