Adit A. Ginde

Demographic Differences and Trends of Vitamin D Insufficiency in the US Population, 1988–2004

BACKGROUND Vitamin D insufficiency is associated with suboptimal health. The prevalence of vitamin D insufficiency may be rising, but population-based trends are uncertain. We sought to evaluate US population trends in vitamin D insufficiency. METHODS We compared serum 25-hydroxyvitamin D (25[OH]D) levels from the Third National Health and Nutrition Examination Survey (NHANES III), collected during 1988 through 1994, with NHANES data collected from 2001 through 2004 (NHANES 2001-2004). Complete data were available for 18 883 participants in NHANES III and 13 369 participants in NHANES 2001-2004. RESULTS The mean serum 25(OH)D level was 30 (95% confidence interval [CI], 29-30) ng/mL during NHANES III and decreased to 24 (23-25) ng/mL during NHANES 2001-2004. Accordingly, the prevalence of 25(OH)D levels of less than 10 ng/mL increased from 2% (95% CI, 2%-2%) to 6% (5%-8%), and 25(OH)D levels of 30 ng/mL or more decreased from 45% (43%-47%) to 23% (20%-26%). The prevalence of 25(OH)D levels of less than 10 ng/mL in non-Hispanic blacks rose from 9% during NHANES III to 29% during NHANES 2001-2004, with a corresponding decrease in the prevalence of levels of 30 ng/mL or more from 12% to 3%. Differences by age strata (mean serum 25[OH]D levels ranging from 28-32 ng/mL) and sex (28 ng/mL for women and 32 ng/mL for men) during NHANES III equalized during NHANES 2001-2004 (24 vs 24 ng/mL for age and 24 vs 24 ng/mL for sex). CONCLUSIONS National data demonstrate a marked decrease in serum 25(OH)D levels from the 1988-1994 to the 2001-2004 NHANES data collections. Racial/ethnic differences have persisted and may have important implications for known health disparities. Current recommendations for vitamin D supplementation are inadequate to address the growing epidemic of vitamin D insufficiency.

Association between serum 25-hydroxyvitamin D level and upper respiratory tract infection in the Third National Health and Nutrition Examination Survey.

BACKGROUND Recent studies suggest a role for vitamin D in innate immunity, including the prevention of respiratory tract infections (RTIs). We hypothesize that serum 25-hydroxyvitamin D (25[OH]D) levels are inversely associated with self-reported recent upper RTI (URTI). METHODS We performed a secondary analysis of the Third National Health and Nutrition Examination Survey, a probability survey of the US population conducted between 1988 and 1994. We examined the association between 25(OH)D level and recent URTI in 18 883 participants 12 years and older. The analysis adjusted for demographics and clinical factors (season, body mass index, smoking history, asthma, and chronic obstructive pulmonary disease). RESULTS The median serum 25(OH)D level was 29 ng/mL (to convert to nanomoles per liter, multiply by 2.496) (interquartile range, 21-37 ng/mL), and 19% (95% confidence interval [CI], 18%-20%) of participants reported a recent URTI. Recent URTI was reported by 24% of participants with 25(OH)D levels less than 10 ng/mL, by 20% with levels of 10 to less than 30 ng/mL, and by 17% with levels of 30 ng/mL or more (P < .001). Even after adjusting for demographic and clinical characteristics, lower 25(OH)D levels were independently associated with recent URTI (compared with 25[OH]D levels of > or =30 ng/mL: odds ratio [OR], 1.36; 95% CI, 1.01-1.84 for <10 ng/mL and 1.24; 1.07-1.43 for 10 to <30 ng/mL). The association between 25(OH)D level and URTI seemed to be stronger in individuals with asthma and chronic obstructive pulmonary disease (OR, 5.67 and 2.26, respectively). CONCLUSIONS Serum 25(OH)D levels are inversely associated with recent URTI. This association may be stronger in those with respiratory tract diseases. Randomized controlled trials are warranted to explore the effects of vitamin D supplementation on RTI.

Prospective study of serum 25-hydroxyvitamin D level, cardiovascular disease mortality, and all-cause mortality in older U.S. adults.

OBJECTIVES: To evaluate the association between serum 25‐hydroxyvitamin D (25(OH)D) levels and mortality in a representative U.S. sample of older adults.

Serum 25-Hydroxyvitamin D Levels Among US Children Aged 1 to 11 Years: Do Children Need More Vitamin D?

OBJECTIVE: Single-center studies have suggested that hypovitaminosis D is widespread. Our objective was to determine the serum levels of 25-hydroxyvitamin D (25[OH]D) in a nationally representative sample of US children aged 1 to 11 years. METHODS: Data were obtained from the 2001–2006 National Health and Nutrition Examination Survey. Serum 25(OH)D levels were determined by radioimmunoassay and categorized as <25, <50, and <75 nmol/L. National estimates were obtained by using assigned patient visit weights and reported with 95% confidence intervals (CIs). RESULTS: During the 2001–2006 time period, the mean serum 25(OH)D level for US children aged 1 to 11 years was 68 nmol/L (95% CI: 66–70). Children aged 6 to 11 years had lower mean levels of 25(OH)D (66 nmol/L [95% CI: 64–68]) compared with children aged 1 to 5 years (70 nmol/L [95% CI: 68–73]). Overall, the prevalence of levels at <25 nmol/L was 1% (95% CI: 0.7–1.4), <50 nmol/L was 18% (95% CI: 16–21), and <75 nmol/L was 69% (95% CI: 65–73). The prevalence of serum 25(OH)D levels of <75 nmol/L was higher among children aged 6 to 11 years (73%) compared with children aged 1 to 5 years (63%); girls (71%) compared with boys (67%); and non-Hispanic black (92%) and Hispanic (80%) children compared with non-Hispanic white children (59%). CONCLUSIONS: On the basis of a nationally representative sample of US children aged 1 to 11 years, millions of children may have suboptimal levels of 25(OH)D, especially non-Hispanic black and Hispanic children. More data in children are needed not only to understand better the health implications of specific serum levels of 25(OH)D but also to determine the appropriate vitamin D supplement requirements for children.

Vitamin D insufficiency in pregnant and nonpregnant women of childbearing age in the United States

OBJECTIVE We evaluated vitamin D insufficiency in a nationally representative sample of women and assessed the role of vitamin supplementation. STUDY DESIGN We conducted secondary analysis of 928 pregnant and 5173 nonpregnant women aged 13-44 years from the National Health and Nutrition Examination Survey 2001-2006. RESULTS The mean 25-hydroxyvitamin D (25[OH]D) level was 65 nmol/L for pregnant women and 59 nmol/L for nonpregnant women. The prevalence of 25(OH)D<75 nmol/L was 69% and 78%, respectively. Pregnant women in the first trimester had similar 25(OH)D levels as nonpregnant women (55 vs 59 nmol/L), despite a higher proportion taking vitamin D supplementation (61% vs 32%). However, first-trimester women had lower 25(OH)D levels than third-trimester women (80 nmol/L), likely from shorter duration of supplement use. CONCLUSION Adolescent and adult women of childbearing age have a high prevalence of vitamin D insufficiency. Current prenatal multivitamins (400 IU vitamin D) helped to raise serum 25(OH)D levels, but higher doses and longer duration may be required.

National study of barriers to timely primary care and emergency department utilization among medicaid beneficiaries

STUDY OBJECTIVE We compare the association between barriers to timely primary care and emergency department (ED) utilization among adults with Medicaid versus private insurance. METHODS We analyzed 230,258 adult participants of the 1999 to 2009 National Health Interview Survey. We evaluated the association between 5 specific barriers to timely primary care (unable to get through on telephone, unable to obtain appointment soon enough, long wait in the physicians office, limited clinic hours, lack of transportation) and ED utilization (≥1 ED visit during the past year) for Medicaid and private insurance beneficiaries. Multivariable logistic regression models adjusted for demographics, socioeconomic status, health conditions, outpatient care utilization, and survey year. RESULTS Overall, 16.3% of Medicaid and 8.9% of private insurance beneficiaries had greater than or equal to 1 barrier to timely primary care. Compared with individuals with private insurance, Medicaid beneficiaries had higher ED utilization overall (39.6% versus 17.7%), particularly among those with barriers (51.3% versus 24.6% for 1 barrier and 61.2% versus 28.9% for ≥2 barriers). After adjusting for covariates, Medicaid beneficiaries were more likely to have barriers (adjusted odds ratio [OR] 1.41; 95% confidence interval [CI] 1.30 to 1.52) and higher ED utilization (adjusted OR 1.48; 95% CI 1.41 to 1.56). ED utilization was even higher among Medicaid beneficiaries with 1 barrier (adjusted OR 1.66; 95% CI 1.44 to 1.92) or greater than or equal to 2 barriers (adjusted OR 2.01; 95% CI 1.72 to 2.35) compared with that for individuals with private insurance and barriers. CONCLUSION Compared with individuals with private insurance, Medicaid beneficiaries were affected by more barriers to timely primary care and had higher associated ED utilization. Expansion of Medicaid eligibility alone may not be sufficient to improve health care access.

Validation of ICD-9-CM coding algorithm for improved identification of hypoglycemia visits

BackgroundAccurate identification of hypoglycemia cases by International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes will help to describe epidemiology, monitor trends, and propose interventions for this important complication in patients with diabetes. Prior hypoglycemia studies utilized incomplete search strategies and may be methodologically flawed. We sought to validate a new ICD-9-CM coding algorithm for accurate identification of hypoglycemia visits.MethodsThis was a multicenter, retrospective cohort study using a structured medical record review at three academic emergency departments from July 1, 2005 to June 30, 2006. We prospectively derived a coding algorithm to identify hypoglycemia visits using ICD-9-CM codes (250.3, 250.8, 251.0, 251.1, 251.2, 270.3, 775.0, 775.6, and 962.3). We confirmed hypoglycemia cases by chart review identified by candidate ICD-9-CM codes during the study period. The case definition for hypoglycemia was documented blood glucose 3.9 mmol/l or emergency physician charted diagnosis of hypoglycemia. We evaluated individual components and calculated the positive predictive value.ResultsWe reviewed 636 charts identified by the candidate ICD-9-CM codes and confirmed 436 (64%) cases of hypoglycemia by chart review. Diabetes with other specified manifestations (250.8), often excluded in prior hypoglycemia analyses, identified 83% of hypoglycemia visits, and unspecified hypoglycemia (251.2) identified 13% of hypoglycemia visits. The absence of any predetermined co-diagnosis codes improved the positive predictive value of code 250.8 from 62% to 92%, while excluding only 10 (2%) true hypoglycemia visits. Although prior analyses included only the first-listed ICD-9 code, more than one-quarter of identified hypoglycemia visits were outside this primary diagnosis field. Overall, the proposed algorithm had 89% positive predictive value (95% confidence interval, 86–92) for detecting hypoglycemia visits.ConclusionThe proposed algorithm improves on prior strategies to identify hypoglycemia visits in administrative data sets and will enhance the ability to study the epidemiology and design interventions for this important complication of diabetes care.

Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data

Objectives To assess the overall effect of vitamin D supplementation on risk of acute respiratory tract infection, and to identify factors modifying this effect. Design Systematic review and meta-analysis of individual participant data (IPD) from randomised controlled trials. Data sources Medline, Embase, the Cochrane Central Register of Controlled Trials, Web of Science, ClinicalTrials.gov, and the International Standard Randomised Controlled Trials Number registry from inception to December 2015. Eligibility criteria for study selection Randomised, double blind, placebo controlled trials of supplementation with vitamin D3 or vitamin D2 of any duration were eligible for inclusion if they had been approved by a research ethics committee and if data on incidence of acute respiratory tract infection were collected prospectively and prespecified as an efficacy outcome. Results 25 eligible randomised controlled trials (total 11 321 participants, aged 0 to 95 years) were identified. IPD were obtained for 10 933 (96.6%) participants. Vitamin D supplementation reduced the risk of acute respiratory tract infection among all participants (adjusted odds ratio 0.88, 95% confidence interval 0.81 to 0.96; P for heterogeneity <0.001). In subgroup analysis, protective effects were seen in those receiving daily or weekly vitamin D without additional bolus doses (adjusted odds ratio 0.81, 0.72 to 0.91) but not in those receiving one or more bolus doses (adjusted odds ratio 0.97, 0.86 to 1.10; P for interaction=0.05). Among those receiving daily or weekly vitamin D, protective effects were stronger in those with baseline 25-hydroxyvitamin D levels <25 nmol/L (adjusted odds ratio 0.30, 0.17 to 0.53) than in those with baseline 25-hydroxyvitamin D levels ≥25 nmol/L (adjusted odds ratio 0.75, 0.60 to 0.95; P for interaction=0.006). Vitamin D did not influence the proportion of participants experiencing at least one serious adverse event (adjusted odds ratio 0.98, 0.80 to 1.20, P=0.83). The body of evidence contributing to these analyses was assessed as being of high quality. Conclusions Vitamin D supplementation was safe and it protected against acute respiratory tract infection overall. Patients who were very vitamin D deficient and those not receiving bolus doses experienced the most benefit. Systematic review registration PROSPERO CRD42014013953.

Improved overall trends but persistent racial disparities in emergency department visits for acute asthma, 1993-2005.

BACKGROUND Emergency department (ED) visits for acute asthma provide an important marker of morbidity. OBJECTIVE To describe the epidemiology of ED visits for acute asthma. METHODS We obtained data from the National Hospital Ambulatory Medical Care Survey, 1993 to 2005, and used the primary diagnosis code for asthma (493) to identify cases. We calculated national estimates by using assigned patient visit weights and national rates per 1000 US population with demographic-specific population data from the US Census Bureau. RESULTS From 1993 to 2005, there were approximately 23,800,000 asthma visits, representing 1.8% of all ED visits, or an overall rate of 6.7 visits per 1000 US population. The national visit rate rose between 1993 and 1998 (P(trend) = .05), but was stable (or possibly decreasing) from 1998 to 2005 (P(trend) = .07). Although rates for white subjects decreased by 25% from 1998 to 2005 (P(trend) = .02), the rates for black subjects remained constant (P(trend) = .80). The overall asthma-related ED visit rate was highest among the following groups: age <10 years (13), women (7.2), black subjects (19), Hispanic subjects (7.1), and subjects in the Northeast (9.2). ED administration of inhaled anticholinergic agents increased 20-fold and systemic corticosteroids increased 2-fold from 1993 to 2005 (P(trend) = .02 and .03, respectively), whereas inhaled beta-agonist and inhaled corticosteroid administration was stable (P(trend) = .09 and .34, respectively). CONCLUSION Although asthma-related ED visit rates showed a significant upward trend from 1993 to 1998, our results support the emerging view that the asthma epidemic may have reached a plateau. Nevertheless, the higher visit rates observed among specific demographic groups and widening disparities, particularly among black subjects, remain problematic and warrant further investigation.

Availability and Quality of Computed Tomography and Magnetic Resonance Imaging Equipment in U.S. Emergency Departments

OBJECTIVES The objective was to determine the availability and quality of computed tomography (CT) and magnetic resonance imaging (MRI) equipment in U.S. emergency departments (EDs). The authors hypothesized that smaller, rural EDs have less availability and lower-quality equipment. METHODS This was a random selection of 262 (5%) U.S. EDs from the 2005 National Emergency Department Inventories (NEDI)-USA (http://www.emnet-usa.org/). The authors telephoned radiology technicians about the presence of CT and MRI equipment, availability for ED imaging, and number of slices for the available CT scanners. The analysis was stratified by site characteristics. RESULTS The authors collected data from 260 institutions (99% response). In this random sample of EDs, the median annual patient visit volume was 19,872 (interquartile range = 6,788 to 35,757), 28% (95% confidence interval [CI] = 22% to 33%) were rural, and 27% (95% CI = 21% to 32%) participated in the Critical Access Hospital program. CT scanners were present in 249 (96%) institutions, and of these, 235 (94%) had 24/7 access for ED patients. CT scanner resolution varied: 28% had 1-4 slice, 33% had 5-16 slice, and 39% had a more than 16 slice. On-site MRI was available for 171 (66%) institutions, and mobile MRI for 53 (20%). Smaller, rural, and critical access hospitals had lower CT and MRI availability and less access to higher-resolution CT scanners. CONCLUSIONS Although access to CT imaging was high (>90%), CT resolution and access to MRI were variable. Based on observed differences, the availability and quality of imaging equipment may vary by ED size and location.