Abstract
Background: Delivery of the pneumococcal vaccine (PCV) to street-involved, HIV patients in British Columbia is low due to poor compliance. Since the use of PCV is expected to reduce morbidity and mortality, it may be more cost-effective to provide the vaccine directly to clinics.
Methods: Three strategies were compared for a cohort of 5000 patients: 1) administering PCV at the clinics; 2) giving a prescription for PCV and expecting patients to fill it at a pharmacy and return for administration; and 3) no administration of vaccine. Decision analysis was utilized to map the costs and outcomes of the patients over 5 years and conduct an incremental cost-effectiveness analysis from the perspective of the Ministry of Health.
Results: The average cost per patient was the lowest in Strategy 1 ($549) compared to Strategy 2 ($702) and Strategy 3 ($714). For the cohort, Strategy 1 prevented 269 and 299 additional cases of pneumococcal disease and resulted in a cost savings of $535,000 and $595,000 in direct medical costs when compared to Strategies 2 and 3, respectively. The model was robust to extensive sensitivity analyses.
Conclusions: The Ministry of Health should supply PCV to clinics involved in the care of street-involved HIV patients as this is the most cost-effective strategy.
Résumé
Contexte: L’administration du vaccin anti-pneumococcique (PCV) aux patients de la rue atteints du VIH, en Colombie-Britannique est faible en raison du manque d’assiduité. Il serait plus rentable de fournir le vaccin directement aux cliniques, étant donné que le vaccin PCV est censé réduire la morbidité et la mortalité.
Méthodes: Nous avons mis trois stratégies à l’épreuve, auprès d’une cohorte de 5 000 patients: 1) administrer le PCV en clinique, 2) remettre une ordonnance pour le vaccin PCV au patient et s’attendre à ce qu’il la fasse compléter à la pharmacie et revienne pour le recevoir, et 3) ne pas administrer le vaccin. L’analyse de décision a servi à établir les coûts et les résultats chez les patients pendant plus de cinq ans et d’effectuer une analyse de rentabilité du point de vue du Ministre de la santé.
Résultats: Le coût moyen par patient était le plus bas dans la première stratégie (549 $) comparativement à 702 $ dans la deuxième et à 714 $ dans la troisième stratégie. Pour ce qui est de la cohorte, la première stratégie a prévenu l’apparition de 269 cas puis de 299 autres cas d’infection pneumococcique, entraînant des économies de 535 000 $ et de 595 000 $ respectivement en coûts médicaux directs si on les compare aux stratégies 2 et 3. Le modèle utilisé était robuste jusqu’à la généralisation de l’analyse de sensibilité.
Conclusions: La stratégie la plus rentable pour le Ministre de la santé devrait consister à alimenter en vaccin PCV les cliniques qui sont impliquées dans les interventions de rue auprès des patients atteints du VIH.
Footnotes
Presented as an abstract at the 39th Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC) in San Francisco, California in September 1999.
References
- 1.Janoff EN, Breiman RF, Daley CL, et al. Pneumococcal disease during HIV infection: Epidemiologic, clinical and immunologic perspectives. Ann Intern Med. 1992;117:314–24. doi: 10.7326/0003-4819-117-4-314. [DOI] [PubMed] [Google Scholar]
- 2.Witt DJ, Craven DE, McCabe WR. Bacterial infections in adult patients with the acquired immune deficiency syndrome (AIDS) and AIDS-related complex. Am J Med. 1987;82:900–6. doi: 10.1016/0002-9343(87)90150-1. [DOI] [PubMed] [Google Scholar]
- 3.Polsky B, Gold JWM, Whimbey E, et al. Bacterial pneumonia in patients with the acquired immune deficiency syndrome. Ann Intern Med. 1986;104:38–41. doi: 10.7326/0003-4819-104-1-38. [DOI] [PubMed] [Google Scholar]
- 4.Hirschtick RE, Glassroth J, Jordan MC, et al. Bacterial pneumonia in persons infected with the human immunodeficiency virus. N Engl J Med. 1995;333:845–51. doi: 10.1056/NEJM199509283331305. [DOI] [PubMed] [Google Scholar]
- 5.Garcia-Leoni ME, Moreno S, Rodeno P, et al. Pneumococcal pneumonia in adult hospitalized patients infected with the human immunodeficiency virus. Arch Intern Med. 1992;152:1808–12. doi: 10.1001/archinte.1992.00400210040007. [DOI] [PubMed] [Google Scholar]
- 6.Schuchat A, Broome CV, Hightower A, et al. Use of surveillance for invasive pneumococcal disease to estimate the size of the immunosup-pressed HIV-infected population. JAMA. 1991;265:3275–79. doi: 10.1001/jama.1991.03460240071030. [DOI] [PubMed] [Google Scholar]
- 7.Redd SC, Rutherford GW, Sande MA, et al. The role of human immunodeficiency virus infection in pneumococcal bacteremia in San Francisco residents. J Infect Dis. 1990;162:1012–17. doi: 10.1093/infdis/162.5.1012. [DOI] [PubMed] [Google Scholar]
- 8.Nuorti JP, Butler JC, Gelling L, et al. Epidemiologic relation between HIV and invasive pneumococcal disease in San Francisco County, California. Ann Intern Med. 2000;132:182–90. doi: 10.7326/0003-4819-132-3-200002010-00003. [DOI] [PubMed] [Google Scholar]
- 9.Janoff EN, O’Brien J, Thompson P, et al. Streptococcus pneumoniae colonization, bacteremia, immune response among persons with human immunodeficiency virus. J Infect Dis. 1993;167:49–53. doi: 10.1093/infdis/167.1.49. [DOI] [PubMed] [Google Scholar]
- 10.Prevention of pneumococcal disease. Recommendations of the Advisory Committee on Immunization Practices. MMWR. 1997;46(RR-8):1–24. [PubMed] [Google Scholar]
- 11.Huang KL, Ruben FL, Rinaldo CR, Jr., et al. Antibody response after influenza and pneumococcal immunization in HIV-infected homosexual men. JAMA. 1987;257:2047–50. doi: 10.1001/jama.1987.03390150063035. [DOI] [PubMed] [Google Scholar]
- 12.Daly P, De Vlaming S, Fraser C. Personnal communication.
- 13.Strathdee SA, Palepu A, Hogg R, et al. Barriers to receiving antiretroviral therapy among injection drug users. Can J Infect Dis. 1998;9A:35A. [Google Scholar]
- 14.Evans C. The use of consensus methods and expert panels in pharmacoeconomic studies. Practical applications and methodological shortcomings. Pharmacoeconomics. 1997;12:121–29. doi: 10.2165/00019053-199712020-00003. [DOI] [PubMed] [Google Scholar]
- 15.Robbins JB, Austrian R, Lee CJ, et al. Considerations for formulating the second-generation pneumococcal capsular polysaccharide vaccine with emphasis on the cross-reactive types within groups. J Infect Dis. 1983;148:1136–59. doi: 10.1093/infdis/148.6.1136. [DOI] [PubMed] [Google Scholar]
- 16.Butler JC, Breiman RF, Campbell JF, et al. Pneumococcal polysaccharide vaccine efficacy: An evaluation of current recommendations. JAMA. 1993;270:1826–31. doi: 10.1001/jama.1993.03510150060030. [DOI] [PubMed] [Google Scholar]
- 17.Shapiro ED, Clemens JD. A controlled evaluation of the protective efficacy of pneumococcal vaccine for patients at high risk of serious pneumococcal infections. Ann Intern Med. 1984;101:325–30. doi: 10.7326/0003-4819-101-3-325. [DOI] [PubMed] [Google Scholar]
- 18.Sims RV, Steinmann WC, McConville JH, et al. The clinical effectiveness of pneumococcal vaccine in the elderly. Ann Intern Med. 1988;108:653–57. doi: 10.7326/0003-4819-108-5-653. [DOI] [PubMed] [Google Scholar]
- 19.Shapiro ED, Berg AT, Austrian R, et al. The protective efficacy of polyvalent pneumococcal polysaccharide vaccine. N Engl J Med. 1991;325:1453–60. doi: 10.1056/NEJM199111213252101. [DOI] [PubMed] [Google Scholar]
- 20.Farr BM, Johnston BL, Cobb DK, et al. Preventing pneumococcal bacteremia in patients at risk: Results of a matched case-control study. Arch Intern Med. 1995;155:2336–40. doi: 10.1001/archinte.1995.00430210086013. [DOI] [PubMed] [Google Scholar]
- 21.Hilleman MR, Carlson AJ, McLean AA, et al. Streptococcus pneumoniae polysaccharide vaccine: Age and dose responses, safety, persistence of antibody, revaccination and simultaneous administration of pneumococcal and influenza vaccines. Rev Infect Dis. 1981;3(suppl):S31–S42. doi: 10.1093/clinids/3.Supplement_1.S31. [DOI] [PubMed] [Google Scholar]
- 22.Kraus C, Fischer S, Ansorg R, et al. Pneumococcal antibodies (IgG, IgM) in patients with chronic obstructive lung disease 3 years after pneumococcal vaccination. Med Microbiol Immunol. 1985;174:51–58. doi: 10.1007/BF02123671. [DOI] [PubMed] [Google Scholar]
- 23.Fine MJ, Smith MA, Carson CA, et al. Efficacy of pneumococcal vaccination in adults: A metaanalysis of randomised controlled trials. Arch Intern Med. 1994;154:2666–77. doi: 10.1001/archinte.1994.00420230051007. [DOI] [PubMed] [Google Scholar]
- 24.Anonymous. B.C. Medical Association Guide to Fees. Vancouver: B.C. Medical Association; 1998. [Google Scholar]
- 25.Briggs A. Handling uncertainty in economic evaluation. BMJ. 1999;319:120. doi: 10.1136/bmj.319.7202.120. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 26.Guay M, DeWals P, Hebert R. Pneumococcal immunization program in Montérégie Québec: Feasibility study. Can J Infect Dis. 1999;10(SupplA):53A–56A. doi: 10.1155/1999/149749. [DOI] [Google Scholar]
- 27.De Wals P, Guay M, Drapeau J, et al. Pneumococcal immunization program: Cost-utility analysis for Quebec. Can J Infect Dis. 1999;10(SupplA):46A–47A. [Google Scholar]
- 28.Preventing pneumococcal disease: A Canadian consensus conference. Can J Infect Dis 1999;10(Suppl A):4A-10A. [PubMed]
- 29.Willems JS, Sanders CR, Riddiough MA, et al. Cost-effectiveness of vaccination against pneumococcal pneumonia. N Engl J Med. 1980;303:553–59. doi: 10.1056/NEJM198009043031004. [DOI] [PubMed] [Google Scholar]
- 30.Patrick KM, Woolley FR. A cost-benefit analysis of immunization for pneumococcal pneumonia. JAMA. 1981;245:473–77. doi: 10.1001/jama.1981.03310300027014. [DOI] [PubMed] [Google Scholar]
- 31.Gable CB, Holzer SS, Engelhart L, et al. Pneumococcal vaccine efficacy and associated cost savings. JAMA. 1990;264:2910–15. doi: 10.1001/jama.1990.03450220076026. [DOI] [PubMed] [Google Scholar]
- 32.Sisk J, Riegelman R. Cost-effectiveness of vaccination against pneumococcal pneumonia: An update. Ann Intern Med. 1986;104:79–86. doi: 10.7326/0003-4819-104-1-79. [DOI] [PubMed] [Google Scholar]
- 33.Sisk JE, Moskowitz AJ, Whang W, et al. Cost-effectiveness of vaccination against pneumococcal bacteremia among elderly people. JAMA. 1997;278:1333–39. doi: 10.1001/jama.1997.03550160053038. [DOI] [PubMed] [Google Scholar]
- 34.Rose DN, Schechter CB, Sacks HS, et al. Influenza and pneumococcal vaccination of HIV-infected patients: A policy analysis. Am J Med. 1993;94:160–68. doi: 10.1016/0002-9343(93)90178-R. [DOI] [PubMed] [Google Scholar]