Adherence to risk management guidelines for drugs which cause vitamin D deficiency - big data from the Swedish health system.

Purpose: Several medications are known to cause vitamin D deficiency. The aim of this study is to describe vitamin D testing and supplementation in patients using these "risk medications", thereby assessing adherence to medical guidelines.

Patients and methods: A database with electronic health records for the population in a Swedish County (≈240,000 inhabitants) was screened for patients prescribed the pre-defined "risk medications" during a 2-year period (2014-2015). In total, 12,194 patients were prescribed "risk medications" pertaining to one of the three included pharmaceutical groups. Vitamin D testing and concomitant vitamin D supplementation, including differences between the included pharmaceutical groups, was explored by matching personal identification numbers.

Results: Corticosteroids were prescribed to 10,003 of the patients, antiepileptic drugs to 1,101, and drugs mainly reducing vitamin D uptake to 864. Two hundred twenty-six patients were prescribed >1 "risk medication". Seven hundred eighty-seven patients (6.5%) had been tested during the 2-year period. There were no differences regarding testing frequency between groups. Concomitant supplements were prescribed to 3,911 patients (32.1%). It was more common to be prescribed supplements when treated with corticosteroids. Vitamin D supplementation was more common among tested patients in all three groups. Women were tested and supplemented to a higher extent. The mean vitamin D level was 69 nmol/L. Vitamin D deficiency was found in 24.1% of tested patients, while 41.3% had optimal levels. It was less common to be deficient and more common to have optimal levels among patients prescribed corticosteroids.

Conclusion: Adherence to medical guidelines comprising testing and supplementation of patients prescribed drugs causing vitamin D deficiency needs improvement in Sweden.