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. 2021 Jul 19;59(11):1790-1799.
doi: 10.1515/cclm-2021-0607. Print 2021 Oct 26.

Vitamin D retesting by general practitioners: a factor and cost analysis

Helena Scully  1 , Eamon Laird  2 , Martin Healy  3 , Vivion Crowley  3 , James Bernard Walsh  1 , Kevin McCarroll  1
Affiliations

Vitamin D retesting by general practitioners: a factor and cost analysis

Helena Scully et al. Clin Chem Lab Med. .

Abstract

Objectives: Vitamin D testing by Primary Care doctors is increasing, placing greater workloads on healthcare systems. There is little data though on vitamin D retesting in Ireland. This study aims to investigate the factors associated with vitamin D retesting by Irish General Practitioners (GPs) and examine the resulting costs.

Methods: This is a retrospective analysis over 5 years (2014-2018) of GP requested 25-hydroxyvitamin D (25(OH)D) results in 36,458 patients at a major city hospital in Dublin, Ireland. Those with one test were compared with individuals who were retested and samples categorised to determine changes in status between tests.

Results: Nearly one in four patients (n=8,305) were retested. Positive predictors of retesting were female (p<0.001), age (60-69 years, p<0.001), location (Co. Kildare, p<0.001) and initial deficiency (<30 nmol/L, p<0.001) or insufficiency (30-49.9 nmol/L, p<0.001). Vitamin D status improved on retesting, with deficiency halving on first retest (9 vs. 18%, p<0.001) and dropping to 6% on further retests. About 12.2% of retests were done within 3 months and 29% had ≥2 retests within 1 year. 57% of retests were in those initially vitamin D replete (>50 nmol/L). The annual cost of inappropriate testing was €61,976.

Conclusions: One in four patients were retested and this varied by age, gender and patient location. Over 10% of retests were inappropriately early (<3 months), a third too frequent and over half were in replete individuals incurring significant costs. Clear guidance for GPs on minimum retesting intervals is needed, as well as laboratory ordering systems to limit requests using pre-defined criteria.

Keywords: 25(OH)D; retesting; testing trends; vitamin D.

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References

    1. Scientific Advisory Committee on Nutrition. SACN vitamin D and health report. London, UK: Public Health England; 2016.
    1. Gaksch, M, Jorde, R, Grimnes, G, Joakimsen, R, Schirmer, H, Wilsgaard, T, et al.. Vitamin D and mortality: individual participant data meta-analysis of standardized 25-hydroxyvitamin D in 26916 individuals from a European consortium. PloS One 2017;12:e0170791. https://doi.org/10.1371/journal.pone.0170791.
    1. de Abreu, DF, Eyles, D, Feron, F. Vitamin D, a neuro-immunomodulator: implications for neurodegenerative and autoimmune diseases. Psychoneuroendocrinology 2009;34:S265–77. https://doi.org/10.1016/j.psyneuen.2009.05.023.
    1. Song, Y, Wang, L, Pittas, AG, Del Gobbo, LC, Zhang, C, Manson, JE, et al.. Blood 25-Hydroxy Vitamin D Levels and Incident Type 2 Diabetes: a meta-analysis of prospective studies. Am Diabetes Assoc 2013;36:1422–8. https://doi.org/10.2337/dc12-0962.
    1. Laird, E, McNulty, H, Ward, M, Hoey, L, McSorley, E, Wallace, J, et al.. Vitamin D deficiency is associated with inflammation in older Irish adults. J Clin Endocrinol Metab 2014;99:1807–15. https://doi.org/10.1210/jc.2013-3507.

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