Objective To examine the utilization of 25OHD testing in each state of Australia to determine the cost impact and value and to establish an evidence base enabling the development of 25OHD testing guidelines.

Background Despite rising awareness of 25OHD deficiency and its consequences, there are no national comprehensive reports of pathology test utilization for 25OHD.

Design Longitudinal analysis of all 25OHD pathology tests in Australia.

Setting Primary and Tertiary Care

Measurements Rate of tests per 100000 individuals and benefit for 25OHD, FBC and bone densitometry by state and quarter between 2000 and 2010. Number of 25OHD tests by provider by state and month between 2006 and 2010.

Results 25OHD testing increased 94 fold from 2000 to 2011. Rate varied by state whereby the most southern state represented the highest increase and northern state the lowest increase. In contrast, the rate of a universal test such as FBC remained relatively stable increasing 2.5 fold. Of concern, a 0.5 fold increase in bone densitometry was seen. GPs performed 80% of tests and specialists 20%. Approximately 50% of tests were subsequent with some individuals having up to 79 tests between 2006 and 2010.

Conclusions The rate of 25OHD testing rose dramatically. Consequences of such findings are widespread in terms of quality of care and cost. The marked variation in frequency of 25OHD testing indicates large sums of money are being expended. Further research is required to determine the cost benefit of such expenditure. Our data indicate that adoption of simple guidelines may improve efficiency and effectiveness of 25OHD testing.