Assessment of serum total 25-hydroxyvitamin D assays for Vitamin D External Quality Assessment Scheme (DEQAS) materials distributed at ambient and frozen conditions.

The Vitamin D External Quality Assessment Scheme (DEQAS) distributes human serum samples four times per year to over 1000 participants worldwide for the determination of total serum 25-hydroxyvitamin D [25(OH)D)]. These samples are stored at -40 °C prior to distribution and the participants are instructed to store the samples frozen at -20 °C or lower after receipt; however, the samples are shipped to participants at ambient conditions (i.e., no temperature control). To address the question of whether shipment at ambient conditions is sufficient for reliable performance of various 25(OH)D assays, the equivalence of DEQAS human serum samples shipped under frozen and ambient conditions was assessed. As part of a Vitamin D Standardization Program (VDSP) commutability study, two sets of the same nine DEQAS samples were shipped to participants at ambient temperature and frozen on dry ice. Twenty-eight laboratories participated in this study and provided 34 sets of results for the measurement of 25(OH)D using 20 ligand binding assays and 14 liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods. Equivalence of the assay response for the frozen versus ambient DEQAS samples for each assay was evaluated using multi-level modeling, paired t-tests including a false discovery rate (FDR) approach, and ordinary least squares linear regression analysis of frozen versus ambient results. Using the paired t-test and confirmed by FDR testing, differences in the results for the ambient and frozen samples were found to be statistically significant at p < 0.05 for four assays (DiaSorin, DIAsource, Siemens, and SNIBE prototype). For all 14 LC-MS/MS assays, the differences in the results for the ambient- and frozen-shipped samples were not found to be significant at p < 0.05 indicating that these analytes were stable during shipment at ambient conditions. Even though assay results have been shown to vary considerably among different 25(OH)D assays in other studies, the results of this study also indicate that sample handling/transport conditions may influence 25(OH)D assay response for several assays.

Assessment of serum total 25-hydroxyvitamin D assay commutability of Standard Reference Materials and College of American Pathologists Accuracy-Based Vitamin D (ABVD) Scheme and Vitamin D External Quality Assessment Scheme (DEQAS) materials: Vitamin D Standardization Program (VDSP) Commutability Study 2.

An interlaboratory study was conducted through the Vitamin D Standardization Program (VDSP) to assess commutability of Standard Reference Materials® (SRMs) and proficiency testing/external quality assessment (PT/EQA) samples for determination of serum total 25-hydroxyvitamin D [25(OH)D] using ligand binding assays and liquid chromatography-tandem mass spectrometry (LC-MS/MS). A set of 50 single-donor serum samples were assigned target values for 25-hydroxyvitamin D2 [25(OH)D2] and 25-hydroxyvitamin D3 [25(OH)D3] using reference measurement procedures (RMPs). SRM and PT/EQA samples evaluated included SRM 972a (four levels), SRM 2973, six College of American Pathologists (CAP) Accuracy-Based Vitamin D (ABVD) samples, and nine Vitamin D External Quality Assessment Scheme (DEQAS) samples. Results were received from 28 different laboratories using 20 ligand binding assays and 14 LC-MS/MS methods. Using the test assay results for total serum 25(OH)D (i.e., the sum of 25(OH)D2 and 25(OH)D3) determined for the single-donor samples and the RMP target values, the linear regression and 95% prediction intervals (PIs) were calculated. Using a subset of 42 samples that had concentrations of 25(OH)D2 below 30 nmol/L, one or more of the SRM and PT/EQA samples with high concentrations of 25(OH)D2 were deemed non-commutable using 5 of 11 unique ligand binding assays. SRM 972a (level 4), which has high exogenous concentration of 3-epi-25(OH)D3, was deemed non-commutable for 50% of the LC-MS/MS assays.

Idiopathic pulmonary fibrosis: Educational needs of health-care providers, patients, and caregivers.

Idiopathic pulmonary fibrosis (IPF) is a progressive disease associated with poor quality of life. Debilitating symptoms and the reality of shortened survival impact patients' physical and emotional well-being and constrain the lives of patients' caregivers. This study assessed the informational needs of medical providers who care for patients with IPF, IPF patients themselves, and their caregivers. Tailored surveys were sent electronically to providers, patients with IPF, and caregivers of patients with IPF collected on a rolling basis in March of 2017. Providers answered questions regarding their own informational needs and what information they believed patients needed. Patients and caregivers identified their own informational needs and the perceived needs for each other. About 2636 surveys were sent to providers, including 2041 to physicians, of whom 156 completed it. One hundred sixty patients and 29 caregivers responded to the survey via a link on a website. Eighty-six percent of providers described themselves as physicians who diagnose and treat IPF patients themselves. Providers ranked information on "making the diagnosis of IPF" as their top informational need. Patients and caregivers chose "disease progression/what to expect" as the most important informational need for themselves and for each other. Providers want to make a correct diagnosis when IPF is in the differential diagnosis. Patients and caregivers desire clarity around how IPF will behave over time and what their futures with IPF will look like. Resources for patients and their caregivers should include information on disease natural history in empathically worded, clear, and easily accessible formats.

Baseline Assessment of 25-Hydroxyvitamin D Reference Material and Proficiency Testing/External Quality Assurance Material Commutability: A Vitamin D Standardization Program Study.

The Vitamin D Standardization Program (VDSP) coordinated a study in 2012 to assess the commutability of reference materials and proficiency testing/external quality assurance materials for total 25-hydroxyvitamin D [25(OH)D] in human serum, the primary indicator of vitamin D status. A set of 50 single-donor serum samples as well as 17 reference and proficiency testing/external quality assessment materials were analyzed by participating laboratories that used either immunoassay or LC-MS methods for total 25(OH)D. The commutability test materials included National Institute of Standards and Technology Standard Reference Material 972a Vitamin D Metabolites in Human Serum as well as materials from the College of American Pathologists and the Vitamin D External Quality Assessment Scheme. Study protocols and data analysis procedures were in accordance with Clinical and Laboratory Standards Institute guidelines. The majority of the test materials were found to be commutable with the methods used in this commutability study. These results provide guidance for laboratories needing to choose appropriate reference materials and select proficiency or external quality assessment programs and will serve as a foundation for additional VDSP studies.

Family structure and fathers' well-being: trajectories of mental health and self-rated health.

The association between marital status and health among men has been well documented, but few studies track health trajectories following family structure transitions among unmarried fathers. Using the Fragile Families and Child Wellbeing Study this article examines trajectories of paternal mental health and self-rated health, focusing on transitions into and out of residential relationships with the child's biological mother or a new partner during a five-year post-birth period (N = 4,331). Continuously married fathers report higher time-specific self-rated health and fewer mental health problems than continuously single fathers, controlling for underlying health trajectories. The disparity, however does not increase over time, providing little support for the marital resource model during these years. Static group differences suggest that resources fathers carry with them into unions may buffer them from the negative effects of union dissolution. The implications of these findings for cohabitation, as well as selection and causation arguments, are also discussed.

Race-ethnic inequality and psychological distress: depressive symptoms from adolescence to young adulthood.

Social inequality is well established in the mental health of race-ethnic groups, but little is known about this disparity from adolescence to young adulthood. This study examined differences in trajectories of depressive symptoms across 4 race-ethnic groups (Whites, Blacks, Hispanics, and Asians) using 3 waves of the National Longitudinal Study of Adolescent Health. Latent trajectory analyses showed race-ethnic variations among both females and males. Stressors were significantly related to depressive symptoms for all study members, but they accounted for symptom trajectories only among Black males and minority females. Persistent differences in trajectories for Blacks and Whites showed parallel slopes that did not converge over time. Neither background characteristics nor social resources (i.e., social support) altered this gap. However, social support represents a potential equalizer of these race-ethnic differences, owing to the ubiquitous nature of its protective effects.