Objective To extend previous analysis of pathology test utilization of 25-hydroxyvitamin D (25(OH)D) testing in Australia and determine the cost impact of 25(OH)D testing in comparison to blood glucose (BGL) and thyroid function testing.

Design Longitudinal analysis of all 25(OH)D, blood glucose and thyroid function (TFT) pathology tests in Australia between January 2010 and December 2012

Setting Primary and Tertiary Care

Measurements Annual Medicare benefit paid for 25(OH)D, BGL and TFT testing between January 2010 and December 2012,

Results The Medicare benefit paid for 25(OH)D testing in Australia increased by 18% between from 2010 to 2011 and 28% from 2011 to 2012, equating to $96.6 million in 2010 to $146.6 million in 2012. During the same period, the rate of BGL and TFT testing increased between 9.3% and 11.3%, and 1.9 and 6.8%, respectively (Table 1). 

Conclusions In concordance with our previous findings of overdiagnosis and overtesting, the cost of vitamin D deficiency to the Australian healthcare system continued to rise at an unsustainable rate, although the increase was lower than our previous findings, which showed an average increase of 59% over the past decade.[1] The cost to Medicare of 25(OH)D testing was almost five times greater than TFTs and 23 times that of BGL tests. These findings reinforce the urgent need for adoption of specific guidelines to improve efficiency and effectiveness of 25(OH)D testing

Table 1: Medicare benefit paid (percentage increase from previous year)

Period	TFT	BGL	25OHD
2010 2011 2012	41,954,487 45,873,653 (9.3%) 51,055,357(11.3%)	5,801,711  5,913,396 (1.9%) 6,314,082 (6.8%)	96,746,201  114,212,797(18.1%) 146,604,412 (28.4%)

1. Bilinski KL, Boyages SC. The rising cost of vitamin D testing in Australia: time to establish guidelines for testing. Med J Aust 2012;197(2):90