Surge in US Outpatient Vitamin D Deficiency Diagnoses
Surge in US Outpatient Vitamin D Deficiency Diagnoses
Although the increase in diagnoses of vitamin D deficiencies beginning in 2007 may be attributed to several factors, the most compelling factors are the 2007 change in the guidelines that physicians use to define vitamin D deficiency and the increase in publicity about and awareness of vitamin D deficiency screening. In addition, both physician and patient awareness of the known and potential consequences of vitamin D deficiency has grown because of a substantial increase in both academic and general media periodicals concerning vitamin D deficiency. An increase in diagnoses among adults for bone disease also occurred from 2007 to 2009. The concurrent increase in visits for osteoporosis and vitamin D deficiency may be in part the result of more surveillance by physicians. The increase also may be attributed to the aging US population, which could result in patients being at risk for developing osteoporosis.
Being older than 65 years or female was associated with a higher rate of visits linked with a vitamin D deficiency diagnosis. Although being older in age and being female are associated with an increased risk of osteoporosis, there were no statistical differences in the prevalence of vitamin D deficiency between the two age groups or between the sexes. Consequently, diagnoses were possibly rendered as preventive measures for these two subgroups.
The NAMCS and outpatient department portion of the NHAMCS datasets are nationally representative and generalizable to the outpatient setting. The reliability of information provided in the NAMCS database is bolstered in that diagnoses and measures are recorded by physicians or their appointed designees.
A limitation of this study is the absence of the criteria used to diagnose vitamin D deficiency. Such measures may vary from serum 25(OH)D concentrations to sun exposure or dietary intake data to other information garnered from patients, all of which can help to confirm the diagnosis. Because of the design of the surveys used, we are not able to directly confirm why there was a surge in diagnoses in recent years. In addition, the small sample size (N = 292) limited our ability to conduct subgroup analyses. Despite the small sample size, these data still illustrate a sharp increase in recent years of diagnosis-linked visits, especially vitamin D deficiency diagnoses not linked with an additional diagnosis for bone disease.
Although vitamin D deficiency can manifest itself in highly visible deformities, in the present analysis, 90% of the diagnoses were not associated with a vitamin D deficiency–related disease (osteoporosis or bone fracture). This finding may suggest that screening for vitamin D deficiency in these patients was used as a preventive measure rather than as a diagnostic aid. We emphasize the importance of providing consistent guidelines, testing procedures, and diagnostic criteria to healthcare providers so that they can make informed decisions when screening patients for vitamin D deficiency. Identifying and screening individuals at risk for vitamin D deficiency is clinically valuable; however, unwarranted, excessive screening may tax the healthcare system unnecessarily.
Discussion
Although the increase in diagnoses of vitamin D deficiencies beginning in 2007 may be attributed to several factors, the most compelling factors are the 2007 change in the guidelines that physicians use to define vitamin D deficiency and the increase in publicity about and awareness of vitamin D deficiency screening. In addition, both physician and patient awareness of the known and potential consequences of vitamin D deficiency has grown because of a substantial increase in both academic and general media periodicals concerning vitamin D deficiency. An increase in diagnoses among adults for bone disease also occurred from 2007 to 2009. The concurrent increase in visits for osteoporosis and vitamin D deficiency may be in part the result of more surveillance by physicians. The increase also may be attributed to the aging US population, which could result in patients being at risk for developing osteoporosis.
Being older than 65 years or female was associated with a higher rate of visits linked with a vitamin D deficiency diagnosis. Although being older in age and being female are associated with an increased risk of osteoporosis, there were no statistical differences in the prevalence of vitamin D deficiency between the two age groups or between the sexes. Consequently, diagnoses were possibly rendered as preventive measures for these two subgroups.
The NAMCS and outpatient department portion of the NHAMCS datasets are nationally representative and generalizable to the outpatient setting. The reliability of information provided in the NAMCS database is bolstered in that diagnoses and measures are recorded by physicians or their appointed designees.
A limitation of this study is the absence of the criteria used to diagnose vitamin D deficiency. Such measures may vary from serum 25(OH)D concentrations to sun exposure or dietary intake data to other information garnered from patients, all of which can help to confirm the diagnosis. Because of the design of the surveys used, we are not able to directly confirm why there was a surge in diagnoses in recent years. In addition, the small sample size (N = 292) limited our ability to conduct subgroup analyses. Despite the small sample size, these data still illustrate a sharp increase in recent years of diagnosis-linked visits, especially vitamin D deficiency diagnoses not linked with an additional diagnosis for bone disease.
Although vitamin D deficiency can manifest itself in highly visible deformities, in the present analysis, 90% of the diagnoses were not associated with a vitamin D deficiency–related disease (osteoporosis or bone fracture). This finding may suggest that screening for vitamin D deficiency in these patients was used as a preventive measure rather than as a diagnostic aid. We emphasize the importance of providing consistent guidelines, testing procedures, and diagnostic criteria to healthcare providers so that they can make informed decisions when screening patients for vitamin D deficiency. Identifying and screening individuals at risk for vitamin D deficiency is clinically valuable; however, unwarranted, excessive screening may tax the healthcare system unnecessarily.
