Changes to the frequency and appropriateness of vitamin D testing after the introduction of new Medicare criteria for rebates in Australian general practice: evidence from 1.5 million patients in the NPS MedicineInsight database

Abstract

ObjectivesTo assess changes in the frequency of vitamin D testing and detection of moderate/severe vitamin D deficiency (<30 nmol/L) among adults after the introduction of new Medicare Benefits Schedule (MBS) rebate criteria (November 2014), and their relationship to sociodemographic and clinical characteristics.DesignDynamic (open) cohort studySettingPrimary careParticipantsAbout 1.5 million ‘active’ patients aged 18+ years visiting a general practitioner and included in the National Prescribing Service MedicineInsight database.Outcome measuresThe frequency of vitamin D testing (per 1000 consultations) and moderate/severe vitamin D deficiency (%) recorded between October 2013 and March 2016, stratified by the release of the new MBS criteria for rebate.ResultsMore patients were female (57.7%) and 30.2% were aged 60+ years. Vitamin D testing decreased 47% (from 40.3 to 21.4 tests per 1000 consultations) after the new MBS criteria, while the proportion of tests with no indication for being performed increased from 71.3% to 76.5%. The proportion of patients identified as moderate/severe vitamin D deficient among those tested increased from 5.4% to 6.5%. Practices located in high socioeconomic areas continued to have the highest rates of testing, but moderate/severe vitamin D deficiency detection remained 90% more frequent in practices from low socioeconomic areas after the rebate change. Furthermore, the frequency of individuals being tested was reduced independent of the patients’ sociodemographic or clinical condition, and the gap in the prevalence of vitamin D deficiency detection between those meeting or not meeting the criteria for being tested remained the same. Moderate/severe vitamin D deficiency detection decreased slightly among patients with hyperparathyroidism or chronic renal failure.ConclusionsAlthough the new criteria for rebate almost halved the frequency of vitamin D testing, it also lessened the frequency of testing among those at higher risk of deficiency, with only a small improvement in vitamin D deficiency detection.

Vitamin D testing: Impact of changes to testing guidelines on detection of patients at risk of vitamin D deficiency

“…Our findings differ to that of Gonzalez-Chica et al., 8 in that we found that the detection rate of patients with severe deficiency (serum 25(OH)D levels <25 nmol/L) was significantly reduced from 2.6% before to 1.6% of patients tested after the intervention; Gonzalez-Chica et al. found some 5.4% of patients at the slightly higher level of serum 25(OH)D <30 nmol/L before compared to 6.4% afterwards.…”

“…It could be argued that such outcomes are difficult to measure, but that is not always the case as indicated by this study and that of Gonzalez et al. 8…”

“…7 A more recent publication confirmed an immediate reduction in vitamin D test requests from General Practitioners up to March 2016, 14 months after the introduction of these guidelines. 8 These authors also described a decrease in the frequency of testing of those at higher risk of deficiency with only a small improvement in detection of patients with moderate to severe vitamin D deficiency which is defined as a serum 25(OH)D <25 nmol/L according to the position statement from the Royal College of Pathologists of Australasia, which defines vitamin D sufficiency as a 25(OH)D level of >50 nmol/L and mild deficiency as 25-50 nmol/L. 9 It is not known whether these reductions in testing numbers and costs have been sustained after March 2016.…”

Potentially inappropriate testing for vitamin D deficiency: a cross-sectional study in Switzerland

“…Other studies have gone one step further in trying to improve the allocation of vitamin D tests in practice. An Australian study showed that a strategy to tackle the number of tests does not necessarily correlate with more appropriate testing [ 32 ]. Another study focused on improving vitamin D supplementation in aged care without measuring vitamin D levels, but care facilities still identified physicians’ beliefs and attitudes related to blood tests as a barrier to routine supplementation [ 33 ].…”

<p>Trends in Micronutrient Laboratory Testing in Switzerland: A 7-Year Retrospective Analysis of Healthcare Claims Data</p>

“…[3][4][5][6] For example, increased testing for vitamin D has been observed in several countries, and even though guidelines do not advocate or even discourage screening for vitamin D deficiency. [5][6][7][8][9][10] In Switzerland, a recent database analysis found increasing MLT use in general practice but comprehensive population-based studies are still lacking. 11 Such insights, however, are necessary to advance the understanding of potential overuse of MLT.…”