Cost-effectiveness analysis of routine pneumococcal vaccination in the UK: a comparison of the PHiD-CV vaccine and the PCV-13 vaccine using a Markov model

Abstract

Objectives: In 2010, the 13-valent pneumococcal conjugate vaccine (PCV-13) replaced the 7-valent vaccine (introduced in 2006) for vaccination against invasive pneumococcal diseases (IPDs), pneumonia and acute otitis media (AOM) in the UK. Using recent evidence on the impact of PCVs and epidemiological changes in the UK, we performed a cost-effectiveness analysis (CEA) to compare the pneumococcal non-typeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV) with PCV-13 in the ongoing national vaccination programme.

Design: CEA was based on a published Markov model. The base-case scenario accounted only for direct medical costs. Work days lost were considered in alternative scenarios.

Setting: Calculations were based on serotype and disease-specific vaccine efficacies, serotype distributions and UK incidence rates and medical costs.

Population: Health benefits and costs related to IPD, pneumonia and AOM were accumulated over the lifetime of a UK birth cohort.

Interventions: Vaccination of infants at 2, 4 and 12 months with PHiD-CV or PCV-13, assuming complete coverage and adherence.

Outcome measures: The incremental cost-effectiveness ratio (ICER) was computed by dividing the difference in costs between the programmes by the difference in quality-adjusted life-years (QALY).

Results: Under our model assumptions, both vaccines had a similar impact on IPD and pneumonia, but PHiD-CV generated a greater reduction in AOM cases (161 918), AOM-related general practitioner consultations (31 070) and tympanostomy tube placements (2399). At price parity, PHiD-CV vaccination was dominant over PCV-13, saving 734 QALYs as well as £3.68 million to the National Health Service (NHS). At the lower list price of PHiD-CV, the cost-savings would increase to £45.77 million.

Conclusions: This model projected that PHiD-CV would provide both incremental health benefits and cost-savings compared with PCV-13 at price parity. Using PHiD-CV could result in substantial budget savings to the NHS. These savings could be used to implement other life-saving interventions.

Keywords: HEALTH ECONOMICS; IMMUNOLOGY.

Figure 1

Model flow diagram. Rectangles represent mutually exclusive health states. Age-specific incidences are applied monthly to the susceptible population. Circles (sequelae and death) and small arrows (natural death) represent the proportion of the population removed from the model. Costs and benefits are computed monthly and aggregated over the cohort's lifetime. Non-consulting AOM episodes are accounted for in the quality of life calculation. AOM, acute otitis media; Sp, Streptococcus pneumoniae; TTP, tympanostomy tube placement.

Figure 2

One-way sensitivity analysis. Effect on the difference in QALY gained and on the difference in direct cost using the lower (light blue bullet) and upper bound value (brown bullet) of one parameter (-n-) and keeping all other parameters equal to the estimated value that is used for calculating the base case. Each parameter will provide two ICERs according its lower and upper bound (values in online supplementary table S1 in file 4). Parameter are ranked in descending order according to the spread between their two ICERs, with the highest spread referring to the most influencing parameter in the CEA analysis (acute disutility for AOM outpatient). AOM, acute otitis media; CEA, cost-effectiveness analysis; comparator=PHiD-CV, pneumococcal non-typeable Haemophilus influenzae protein D conjugate vaccine; GP, general practitioner; ICER, incremental cost-effectiveness ratio (=difference in direct cost divided by difference in QALY gained divided); NTHi, non-typeable Haemophilus influenzae; QALY, quality-adjusted life-year; Sp, Streptococcus pneumonia; standard intervention=PCV-13, 13-valent pneumococcal conjugate vaccine; VT, vaccine type.

Figure 3

Probabilistic sensitivity analysis. Probabilistic distributions have been defined around each parameter and 500 different parameter sets were sampled by varying all parameters simultaneously. The red point in the cost-effectiveness plane represents the base-case parameter set. QALY, quality-adjusted life-year.