Abstract
Objective: Pregnancy is associated with increased influenza hospitalizations and physician visits (events) in healthy women and those with co-morbidities. Annual influenza immunization is recommended for all pregnant women. Although vaccination is expected to reduce influenza-related events, the economic implications are unclear. We developed an economic model to estimate the cost-effectiveness (CE) of different vaccination strategies in Nova Scotia.
Methods: A decision tree characterized the one-year costs and consequences of targeted (pregnant women with co-morbidities only) and universal (all pregnant women) vaccination strategies relative to a no-vaccination strategy. Baseline event probabilities, vaccine effectiveness, costs and quality-of-life weights were derived from individual-level Nova Scotia administrative databases, health system sources and published reports. Sensitivity analyses tested the impact of varying key parameters, including vaccine effectiveness and mode of delivery.
Results: Targeted vaccination was cost-saving relative to no vaccination when delivered by public health clinics (PHC) or routine family practitioner (FP) visit. Cost per quality-adjusted life year gained by universal vaccination relative to targeted strategy was <$40,000 when delivered by PHC or routine FP visit. Net cost of universal vaccination by PHC or a routine FP visit was <$10 per pregnant woman.
Conclusion: Universal vaccination of pregnant women appears cost-effective when delivered by PHC or as part of a routine FP prenatal visit. Targeted vaccination of pregnant women with co-morbidities can be cost-saving, but the possibility of higher vaccine uptake with a universal compared to a targeted strategy must be considered in addition to costs in program planning.
Key words: Influenza, human, vaccination, pregnancy, cost-benefit analysis
Résumé
Objectif: La grossesse est associée à des hausses de certains événements liés à la grippe (hospitalisations et visites chez le médecin) chez les femmes en bonne santé comme chez les femmes atteintes de comorbidités. On recommande le vaccin annuel contre la grippe à toutes les femmes enceintes. On sait que la vaccination réduit les événements liés à la grippe, mais ses répercussions économiques ne sont pas claires. Nous avons élaboré un modèle économique pour estimer le rapport coût-efficacité de diverses stratégies de vaccination en Nouvelle-Écosse.
Méthode: Au moyen d’un arbre de décision, nous avons caractérisé les coûts et les conséquences sur un an de stratégies de vaccination ciblées (seulement les femmes enceintes avec des comorbidités) et universelles (toutes les femmes enceintes) comparativement à une stratégie de nonvaccination. Les probabilités de base de survenue des événements, l’efficacité du vaccin, les coûts et la pondération selon la qualité de vie ont été dérivés de bases de données administratives par personne de Nouvelle-Écosse, de sources du système de santé et de rapports publiés. Des analyses de sensibilité ont permis de tester l’incidence de divers paramètres clés, dont l’efficacité du vaccin et son mode d’administration.
Résultats: La vaccination ciblée était plus économique que l’absence de vaccination lorsqu’elle était administrée dans les cliniques de santé publique (CSP) ou lors d’une visite ordinaire chez le médecin de famille (MF). Comparativement à la stratégie ciblée, le coût de la vaccination universelle, par année de survie ajustée pour la qualité de vie, était de <40 000 $ lorsque le vaccin était administré dans une CSP ou par le MF. Le coût net de la vaccination universelle dans une CSP ou par le MF était de <10 $ par femme enceinte.
Conclusion: La vaccination universelle des femmes enceintes semble rentable lorsque le vaccin est administré dans une CSP ou lors d’une visite prénatale ordinaire chez le MF. La vaccination ciblée des femmes enceintes présentant des comorbidités peut être rentable, mais en plus des coûts de planification de programme, il faut tenir compte de la possibilité d’une plus grande acceptation du vaccin avec une stratégie universelle comparativement à une stratégie ciblée.
Mots clés: grippe humaine, vaccination, grossesse, analyse coût-bénéfice
Footnotes
Funding: Capital Health Research Fund.
Conflict of Interest: None to declare.
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