Immunoglobulin replacement therapy (IgGRT) in CVID aims to reduce recurrent infections and increased mortality. We aimed to build a CVID health-economic model and to evaluate the cost-utility (CU) of IgGRT (intervention) compared to no IgGRT (comparator).
Based on a literature review, we built a Markov chain model with seven distinct health states (cycle length 1 month), simulating progression from a ‘controlled state’ to minor infections, major infections, bronchiectasis, auto-immune disease, cancer and death. Time horizon was set at 50 years. The outcomes included Quality-Adjusted Life Years (QALYs) and healthcare costs, both were extracted from publically available sources. Annual discounting was set at 3% for QALYs and 6% for costs. Monthly probabilities were converted from rates using the followingformula: rate=−ln(1-p)/t.
Cumulative 50-years-mortality was 98% in the no IgGRT group and 45% in case of IgGRT. The discounted cost and QALY results were as follows:
| Results | No IgGRT | IgGRT | Difference |
| Healthcare cost total | € 38,722.73 | € 346,031.41 | € 307,308.69 |
| QALY total | 7.81 | 18.25 | 10.43 |
The incremental cost-utility ratio (ICUR) was €29,454/QALY after discounting.
Without IgGRT, healthcare costs are limited because of the lack of associated treatment costs and high patient mortality. IgGRT increases survival and QoL with an incremental benefit per patient estimated at 10.4 QALYs. The ICUR is ~ €29,500/QALY which is illustrating the efficiency of optimal IgG-treatment.