A cost analysis of systematic vitamin D supplementation in the elderly versus supplementation based on assessed requirements

Hypovitaminosis D is common among older people and treatment with vitamin D is associated with reduced risk of falls and fractures. This paper provides a cost analysis of assessing the vitamin D status of and providing the pharmaceuticals for elderly citizens in Kalmar County, Sweden (population approximately 230,000). Four hypothetical interventions were analyzed: (a) systematic vitamin D/calcium supplementation to all elderly (≥75 years), (b) assessment of vitamin D status in elderly and supplementation to those with insufficient levels, (c) systematic vitamin D/calcium supplementation to all nursing-home residents, and (d) assessment of vitamin D status in nursing-home residents and supplementation to those with insufficient levels. The calculations were based on an estimated reduction in overall costs due to the assessed number of hip fractures after vitamin D/calcium supplementation. The annual net economic benefit of vitamin D/calcium supplementation was estimated at (a) €304,000, (b) €860,000, (c) €755,000, and (d) €740,000. The provision of systematic vitamin D supplementation to nursing-home residents would provide a substantial net economic benefit to society and assessment of the vitamin D status before starting supplementation does not seem to be necessary. Although assessment of all elderly citizens would be more comprehensive, the true proportion with insufficient vitamin D levels in the general population is uncertain and to reaching consensus on the most advantageous daily vitamin D intake, vitamin D blood levels are necessary. Also, systematic supplementation to all elderly would result in other outcomes that could be worth the cost, but that remains to be evaluated. DOI : 10.14302/issn.2474-7785.jarh-17-1724 Corresponding author: Pär Wanby, MD, PhD, Section of Endocrinology, Department of Internal Medicine, Kalmar County Hospital, SE-391 85 Kalmar, Sweden, E-mail: par.wanby@ltkalmar.se, Phone: +46(0)480-448204


Introduction
Vitamin D is essential for skeletal metabolism, muscle function, calcium homeostasis, and the immune system (1). It has also been presented as a preventive factor for chronic diseases such as cardiovascular disease, type 2 diabetes, autoimmune diseases, and various cancers (2)(3)(4), and for non-vertebral and hip fractures in older patients (2,3,5). Furthermore, low vitamin D levels are reported to be associated with increased mortality among the elderly in Sweden (6,7).
The main source of vitamin D is from sensible sun exposure, and other sources are food and dietary supplements (1,8). People at risk of insufficient vitamin D levels include the elderly and individuals with limited sun exposure, such as those in nursing homes (9).
Moreover, the elderly often avoid direct sunlight and also have a reduced capacity to synthesize vitamin D in their skin (10). Consequently, there are numerous guidelines/recommendations on the management of vitamin D status (1,3,4,8,(11)(12)(13)(14). Most of the recent guidelines/recommendations suggest that S-25(OH)D levels ≥50 nmol/L reflect sufficient vitamin D (1,4,11,13,14). However, in fragile older adults with an elevated risk of falls and fractures, it has been suggested that the minimum S-25(OH)D level should be ≥75 nmol/L (8,13). S-25(OH)D levels were recently reported to be <50 nmol/L in >65% of elderly patients (aged ≥75 years) with hip fractures (15).
Falls and fractures are common among the elderly. Some studies have found that vitamin D supplementation reduces the incidence of falls and fractures (2). Others have found that vitamin D alone does not seem to prevent fractures (16,17), whereas supplements of vitamin D plus calcium reduce the risk of falls (18) and hip fractures in the elderly (16 All costs were taken from published literature and official databases.

Study population
The data were from a Swedish study (15)

Control group
The control group in the main study (n = 169)

Study design
The cost analysis was based on the following  We hypothesized that vitamin D supplementation, with or without calcium, could reduce the number of hip fractures by 30%, according to a published analysis on fracture prevention (19).

Resource units and costs
All costs were estimated in Swedish Crowns (SEK) using 2014 prices and were then converted to euros (€1.00 = SEK9.097); where applicable, the consumer price index was applied as the conversion factor.
The hip fracture cost was based on two previous Swedish studies (32,33) ( Table 1). The cost of transportation to and from Swedish healthcare units was obtained from a previous study (36). The cost of transportation to and from Swedish nursing homes was calculated as the average wage during an estimated one-hour trip with additional travel expenses (€0.203 per km) as per the Swedish public reimbursement policies ( Table 1).

Assessment of vitamin D status
We

Nursing homes
The healthcare personnel would arrange  Approximately 40% of the total hip fracture cost stemmed from nursing-home residents ( Table 2).

Discussion
The provision of systematic vitamin D supplementation to nursing-home residents would provide a substantial net economic benefit to society, and assessment of the vitamin D status before starting supplementation does not seem to be necessary in this high-risk group for vitamin D deficiency.
The intervention with the largest net economic benefit ( Table 2)   Among the nursing-home residents, as many as 76% had a S-25(OH)D level <50 nmol/L (15). A high prevalence of insufficient vitamin D in nursing-home residents has been reported previously (38). In addition, a Swedish study examining the vitamin D status of the elderly in nursing homes found that this highly prevalent vitamin D deficiency was associated with increased mortality (7).
Our decision to use 50 nmol/L as the cut-off point for insufficient S-25(OH)D levels (4,11,13,14) is years, with similar reductions in mortality (22). Another study showed that treatment of the elderly population (aged ≥60 years) with vitamin D3 800 IU daily was associated with reductions in mortality and substantial cost-savings through fall prevention (21).
Supplementation with vitamin D and calcium has been shown to reduce the risk of hip fractures (16).
However, the elderly are often already taking many medications and the addition of yet another pharmaceutical to be taken daily could meet resistance among both physicians and patients. None of the participants in the control group were prescribed vitamin D supplements whereas 14% of the nursing home residents were given supplements (15). However, half of these residents were given a low dose (400 IU) vitamin D. Furthermore, there was no information regarding intake of food sources rich in vitamin D or vitamins not prescribed by a physician, or about exposure to sunlight in either groups (15), which could be important aspects influencing the vitamin D status. The study was based on only one county in Sweden with a population of approximately 230,000 citizens.

Conclusion
The provision of systematic vitamin D supplementation to nursing-home residents would provide a substantial net economic benefit to society, and assessment of the vitamin D status before starting supplementation does not seem to be necessary in this high-risk group for vitamin D deficiency. This advice is in accordance with recommendations offering vitamin D Although assessment of all elderly citizens would be more comprehensive, the true proportion with insufficient vitamin D levels in the general population is still uncertain and to reaching consensus on the most advantageous daily vitamin D intake, vitamin D blood levels are necessary. Also, systematic supplementation to all elderly would result in other outcomes that could be worth the cost, but that remains to be evaluated.