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31 Vitamin D testing overuse at a HMO in Argentina
  1. Malena Chiaborelli,
  2. Camila Volij,
  3. Karin Silvana Kopitowski,
  4. Sergio Adrián Terrasa
  1. Italian Hospital of Buenos Aires, Buenos Aires, Argentina


Lisa Schwartz Scholarship application.

Nowadays, especially in high income countries and middle sectors of developing countries, the phenomenon of medicalization of life is more evident. The better health status people have, the more probable it is that they will have a poor perception of health. Vitamin D tests are an excellent example of this. Many patients and doctors believe that it would always be beneficial to measure it, but it is well known that a test without a clear indication may lead to overdiagnosis, diagnostic cascades of incidental findings and inequality in the distribution of resources. According to the United States Preventive Services Task Force, the evidence to assess the balance between the benefits and harms of screening for vitamin D deficiency in the general population is insufficient. As a consequence, we believe doctors should not offer the test to their patients. In fact, they must be able to explain the pros and cons about it if patients ask for it. Being able to explain these ideas to patients and colleagues may not be an easy task because they are not intuitive concepts and because they may be seen as a way of denying performing the test to the patient. Moreover, doctors from different specialties may have dissenting opinions about testing for vitamin D, so patients may find themselves receiving ambiguous messages. That is why we consider that clear communication is of utmost importance for patients to make informed decisions.

We believe that documenting overuse of vitamin D tests in our institution is the first step to gather precise data that will enable us to spread evidence-based information about the benefits and drawbacks of performing the test, as well as to design institutional strategies to limit this practice only to necessary cases. To actually achieve this, sharing our findings with doctors of different specialties and creating agreement about reducing this low value care practice will be key. Subsequently, creating tools in order to deliver a coherent institutional message to the patients would make doctors feel more supported and less lonely in the task of communicating and it would also allow patients to better understand and accept such position. Inspired by Lisa Schwartz, we think that this contribution will take our community closer to the truth regarding vitamin D testing and avoid overdiagnosis.

Objectives Given the importance of reducing low-value care practices and bearing in mind that serum vitamin D testing in the general population is rising despite the fact that there is no evidence to support such conduct and, moreover, as there are doubts about the interpretation of the results of this test, we decided to investigate the overuse of this determination in adults at a health maintenance organization (HMO) associated to a university hospital in Buenos Aires, Argentina, in late 2022. We considered that it was ‘appropriate’ to administer this test to patients that had a clinical condition that justified it. In contrast, we considered it ‘inappropriate’ when it was performed to healthy asymptomatic patients without adequate indication. Our aim was to determine what proportion of these tests was inappropriately requested. Defining the magnitude of this provision of low-value care will contribute to design strategies to attenuate it.

Method This was a cross-sectional study based on data obtained from the electronic medical records (EMR) of the HMO. The population included all the patients aged between 18 and 64 on the HMO membership list to whom at least one test of vitamin D had been performed between July 1st and December 31st 2022. Presence or suspected diagnosis of any of the following was considered to be an appropriate indication to perform a vitamin D test: osteomalacia; osteoporosis; osteopenia; hip, wrist, spine and pelvis fractures; use of the following drugs: aromatase inhibitors, phenytoin, phenobarbital, carbamazepine, oxcarbazepine, gabapentin, isoniazid or rifampicin; celiac disease; bariatric surgery; cystic fibrosis; inflammatory bowel disease; other malabsorption syndromes; chronic kidney disease; chronic liver disease or multiple sclerosis. Tests performed to patients who did not present these clinical conditions were considered inappropriate. A random sample of EMRs of 242 patients was manually analyzed.

Results During the second semester of 2022, 10,095 vitamin D tests were performed to 9,623 patients (mean age 47, 78.1% female). These patients were 9.8% of the 97,584 HMO members aged between 18 and 64 in 2022. 47.0% of the tests were requested by primary care specialists (family medicine, general internal medicine and gynecology) while the rest was requested by other specialists (endocrinology, nutrition and dermatology among others). 160 of the 242 patients whose EMRs were analyzed (66.1%, CI 95% 60 - 72), did not have a clinical condition that justified vitamin D testing. The most frequent clinical condition found for testing was osteopenia in 37/242 patients (15.4%), the second was osteoporosis in 13/242 (5.4%) and the third was chronic kidney disease 11/242 (4.6%).

Conclusions At least two-thirds of the vitamin D tests performed in adults younger than 65 did not have a clinical condition that justified the practice. Half of the vitamin D tests performed in the population of this study were requested by primary care specialists. These findings about overuse of vitamin D testing in our institution represent an opportunity to design strategies to reduce this low-value care practice.

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