Cost-effectiveness of vitamin D3 supplementation in older adults with vitamin D deficiency in Ireland

ABSTRACT Background This study investigated the cost-effectiveness of vitamin D 3 supplementation in older adults in Ireland, with year-round vitamin D deficiency (serum 25-hydroxyvitamin D concentration <30 nmol/L) (13% of Irish adults), from the perspective of the Health Service Executive (HSE). Methods Three age groups were investigated: (1) ≥50 years, (2) ≥60 years, (3) ≥70 years. Based on the clinical literature, vitamin D 3 supplementation may (1) decrease all-cause mortality by 7%, and (2) reduce hip fractures by 16%, and non-hip fractures by 20%. A discount rate of 4% was applied to life years and QALYs gained. The annual healthcare costs per patient used in the model are based on the average annual health resource use over the 5-year time horizon of the model. Results The cost/QALY estimates in all three age groups are below the usually acceptable cost-effectiveness threshold of €20,000/QALY. The most cost-effective and least costly intervention was in adults ≥70 years. For this age group, the average annual costs and outcomes would be approx. €6.2 million, 1,043 QALYs gained, with a cost/QALY of approx. €6,000. The results are most sensitive to the mortality risk reduction following vitamin D 3 supplementation. Conclusion The cost-effectiveness of vitamin D 3 supplementation is most robust in adults ≥70 years. Clinical uncertainty in the magnitude of the benefits of vitamin D 3 supplementation could be further addressed by means of (1) performing a clinical research study or (2) conducting a pilot/regional study, prior to reaching a decision to invest in a full nationwide programme.