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Biomarker-directed targeted therapy plus durvalumab in advanced non-small-cell lung cancer: a phase 2 umbrella trial. Nat Med 2024; 30:716-729. [PMID: 38351187 PMCID: PMC10957481 DOI: 10.1038/s41591-024-02808-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Accepted: 01/09/2024] [Indexed: 03/23/2024]
Abstract
For patients with non-small-cell lung cancer (NSCLC) tumors without currently targetable molecular alterations, standard-of-care treatment is immunotherapy with anti-PD-(L)1 checkpoint inhibitors, alone or with platinum-doublet therapy. However, not all patients derive durable benefit and resistance to immune checkpoint blockade is common. Understanding mechanisms of resistance-which can include defects in DNA damage response and repair pathways, alterations or functional mutations in STK11/LKB1, alterations in antigen-presentation pathways, and immunosuppressive cellular subsets within the tumor microenvironment-and developing effective therapies to overcome them, remains an unmet need. Here the phase 2 umbrella HUDSON study evaluated rational combination regimens for advanced NSCLC following failure of anti-PD-(L)1-containing immunotherapy and platinum-doublet therapy. A total of 268 patients received durvalumab (anti-PD-L1 monoclonal antibody)-ceralasertib (ATR kinase inhibitor), durvalumab-olaparib (PARP inhibitor), durvalumab-danvatirsen (STAT3 antisense oligonucleotide) or durvalumab-oleclumab (anti-CD73 monoclonal antibody). Greatest clinical benefit was observed with durvalumab-ceralasertib; objective response rate (primary outcome) was 13.9% (11/79) versus 2.6% (5/189) with other regimens, pooled, median progression-free survival (secondary outcome) was 5.8 (80% confidence interval 4.6-7.4) versus 2.7 (1.8-2.8) months, and median overall survival (secondary outcome) was 17.4 (14.1-20.3) versus 9.4 (7.5-10.6) months. Benefit with durvalumab-ceralasertib was consistent across known immunotherapy-refractory subgroups. In ATM-altered patients hypothesized to harbor vulnerability to ATR inhibition, objective response rate was 26.1% (6/23) and median progression-free survival/median overall survival were 8.4/22.8 months. Durvalumab-ceralasertib safety/tolerability profile was manageable. Biomarker analyses suggested that anti-PD-L1/ATR inhibition induced immune changes that reinvigorated antitumor immunity. Durvalumab-ceralasertib is under further investigation in immunotherapy-refractory NSCLC.ClinicalTrials.gov identifier: NCT03334617.
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Previous fracture and subsequent fracture risk: a meta-analysis to update FRAX. Osteoporos Int 2023; 34:2027-2045. [PMID: 37566158 PMCID: PMC7615305 DOI: 10.1007/s00198-023-06870-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 07/22/2023] [Indexed: 08/12/2023]
Abstract
A large international meta-analysis using primary data from 64 cohorts has quantified the increased risk of fracture associated with a previous history of fracture for future use in FRAX. INTRODUCTION The aim of this study was to quantify the fracture risk associated with a prior fracture on an international basis and to explore the relationship of this risk with age, sex, time since baseline and bone mineral density (BMD). METHODS We studied 665,971 men and 1,438,535 women from 64 cohorts in 32 countries followed for a total of 19.5 million person-years. The effect of a prior history of fracture on the risk of any clinical fracture, any osteoporotic fracture, major osteoporotic fracture, and hip fracture alone was examined using an extended Poisson model in each cohort. Covariates examined were age, sex, BMD, and duration of follow-up. The results of the different studies were merged by using the weighted β-coefficients. RESULTS A previous fracture history, compared with individuals without a prior fracture, was associated with a significantly increased risk of any clinical fracture (hazard ratio, HR = 1.88; 95% CI = 1.72-2.07). The risk ratio was similar for the outcome of osteoporotic fracture (HR = 1.87; 95% CI = 1.69-2.07), major osteoporotic fracture (HR = 1.83; 95% CI = 1.63-2.06), or for hip fracture (HR = 1.82; 95% CI = 1.62-2.06). There was no significant difference in risk ratio between men and women. Subsequent fracture risk was marginally downward adjusted when account was taken of BMD. Low BMD explained a minority of the risk for any clinical fracture (14%), osteoporotic fracture (17%), and for hip fracture (33%). The risk ratio for all fracture outcomes related to prior fracture decreased significantly with adjustment for age and time since baseline examination. CONCLUSION A previous history of fracture confers an increased risk of fracture of substantial importance beyond that explained by BMD. The effect is similar in men and women. Its quantitation on an international basis permits the more accurate use of this risk factor in case finding strategies.
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The Aetion Coalition to Advance
Real‐World
Evidence through Randomized Controlled Trial Emulation (
CARE
) Initiative: Oncology. Clin Pharmacol Ther 2022; 113:1217-1222. [DOI: 10.1002/cpt.2800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 11/10/2022] [Indexed: 11/22/2022]
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Update of the fracture risk prediction tool FRAX: a systematic review of potential cohorts and analysis plan. Osteoporos Int 2022; 33:2103-2136. [PMID: 35639106 DOI: 10.1007/s00198-022-06435-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 05/18/2022] [Indexed: 12/15/2022]
Abstract
UNLABELLED We describe the collection of cohorts together with the analysis plan for an update of the fracture risk prediction tool FRAX with respect to current and novel risk factors. The resource comprises 2,138,428 participants with a follow-up of approximately 20 million person-years and 116,117 documented incident major osteoporotic fractures. INTRODUCTION The availability of the fracture risk assessment tool FRAX® has substantially enhanced the targeting of treatment to those at high risk of fracture with FRAX now incorporated into more than 100 clinical osteoporosis guidelines worldwide. The aim of this study is to determine whether the current algorithms can be further optimised with respect to current and novel risk factors. METHODS A computerised literature search was performed in PubMed from inception until May 17, 2019, to identify eligible cohorts for updating the FRAX coefficients. Additionally, we searched the abstracts of conference proceedings of the American Society for Bone and Mineral Research, European Calcified Tissue Society and World Congress of Osteoporosis. Prospective cohort studies with data on baseline clinical risk factors and incident fractures were eligible. RESULTS Of the 836 records retrieved, 53 were selected for full-text assessment after screening on title and abstract. Twelve cohorts were deemed eligible and of these, 4 novel cohorts were identified. These cohorts, together with 60 previously identified cohorts, will provide the resource for constructing an updated version of FRAX comprising 2,138,428 participants with a follow-up of approximately 20 million person-years and 116,117 documented incident major osteoporotic fractures. For each known and candidate risk factor, multivariate hazard functions for hip fracture, major osteoporotic fracture and death will be tested using extended Poisson regression. Sex- and/or ethnicity-specific differences in the weights of the risk factors will be investigated. After meta-analyses of the cohort-specific beta coefficients for each risk factor, models comprising 10-year probability of hip and major osteoporotic fracture, with or without femoral neck bone mineral density, will be computed. CONCLUSIONS These assembled cohorts and described models will provide the framework for an updated FRAX tool enabling enhanced assessment of fracture risk (PROSPERO (CRD42021227266)).
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Evaluating the implementation of enhanced recovery after transoral robotic surgery for oropharyngeal cancer. Clin Nutr ESPEN 2022. [DOI: 10.1016/j.clnesp.2022.06.085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Risk of depression, suicide and psychosis with hydroxychloroquine treatment for rheumatoid arthritis: a multinational network cohort study. Rheumatology (Oxford) 2021; 60:3222-3234. [PMID: 33367863 PMCID: PMC7798671 DOI: 10.1093/rheumatology/keaa771] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 10/19/2020] [Indexed: 12/16/2022] Open
Abstract
OBJECTIVES Concern has been raised in the rheumatology community regarding recent regulatory warnings that HCQ used in the coronavirus disease 2019 pandemic could cause acute psychiatric events. We aimed to study whether there is risk of incident depression, suicidal ideation or psychosis associated with HCQ as used for RA. METHODS We performed a new-user cohort study using claims and electronic medical records from 10 sources and 3 countries (Germany, UK and USA). RA patients ≥18 years of age and initiating HCQ were compared with those initiating SSZ (active comparator) and followed up in the short (30 days) and long term (on treatment). Study outcomes included depression, suicide/suicidal ideation and hospitalization for psychosis. Propensity score stratification and calibration using negative control outcomes were used to address confounding. Cox models were fitted to estimate database-specific calibrated hazard ratios (HRs), with estimates pooled where I2 <40%. RESULTS A total of 918 144 and 290 383 users of HCQ and SSZ, respectively, were included. No consistent risk of psychiatric events was observed with short-term HCQ (compared with SSZ) use, with meta-analytic HRs of 0.96 (95% CI 0.79, 1.16) for depression, 0.94 (95% CI 0.49, 1.77) for suicide/suicidal ideation and 1.03 (95% CI 0.66, 1.60) for psychosis. No consistent long-term risk was seen, with meta-analytic HRs of 0.94 (95% CI 0.71, 1.26) for depression, 0.77 (95% CI 0.56, 1.07) for suicide/suicidal ideation and 0.99 (95% CI 0.72, 1.35) for psychosis. CONCLUSION HCQ as used to treat RA does not appear to increase the risk of depression, suicide/suicidal ideation or psychosis compared with SSZ. No effects were seen in the short or long term. Use at a higher dose or for different indications needs further investigation. TRIAL REGISTRATION Registered with EU PAS (reference no. EUPAS34497; http://www.encepp.eu/encepp/viewResource.htm? id=34498). The full study protocol and analysis source code can be found at https://github.com/ohdsi-studies/Covid19EstimationHydroxychloroquine2.
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Contextualizing a single-arm trial of ceralasertib (cer) plus paclitaxel with real-world data (RWD) in patients (pts) with advanced melanoma previously treated with anti-PD-(L)1(PDx) therapies. J Clin Oncol 2021. [DOI: 10.1200/jco.2021.39.15_suppl.e21542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
e21542 Background: Metastatic melanoma, especially in pts who do not respond to PDx therapy, is an area of high unmet need. Chemotherapy may be used but clinical efficacy is limited. A recent Phase I study (NCT02630199) showed that cer + paclitaxel had promising anti-tumor activity with durable responses in 34 melanoma pts after failing PDx therapy. Given the lack of published prospective clinical trial data in the post-PDx setting, RWD was used to contextualize the results of the trial. Methods: Adult pts (≥18 years) diagnosed with advanced melanoma between Jan2011-Jun2020, who received PDx therapy alone or in combination with anti-CTLA4, and also received chemotherapy immediately after the PDx line (chemo cohort) were selected from the nationwide US-based Flatiron Health EHR-derived de-identified database. A subgroup of pts who received taxane was also selected. Overall survival (OS) was assessed using Kaplan-Meier methods. Key covariates such as age, gender, LDH level, number of prior lines of therapy, presence of brain and liver metastases, and prior BRAF/MEK treatment, were adjusted using propensity score-based weighting approach. Cox regression models were used to obtain the effect estimates for OS comparing the trial arm against the RWD cohorts. Results: A cohort of 114 pts met the inclusion criteria, of which 69 received taxane. Compared with the trial arm, the RWD cohorts were older, contained more males, with higher proportions receiving prior BRAF/MEK inhibitors, with brain metastasis, and LDH≤ULN. Median OS was 7.4 months (mo) in the trial arm, compared to 5.6 (unadjusted) and 3.5 mo (adjusted) in the chemo cohort. Hazard ratio of 0.49 (95% CI: 0.29-0.83, trial vs. chemo) indicated significant benefits of the trial arm over the chemo cohort. Analyses using taxane subgroup showed similar findings. Conclusions: The RWD cohorts demonstrated poor outcomes for the pts receiving chemotherapy, in particular taxanes, confirming this is a population of unmet need. The results show the potential for improved outcomes using cer + paclitaxel in pts previously treated with PDx.[Table: see text]
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The Alignment of Real-World Evidence and Digital Health: Realising the Opportunity. Ther Innov Regul Sci 2021; 55:889-898. [PMID: 33914297 PMCID: PMC8082742 DOI: 10.1007/s43441-021-00288-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 03/26/2021] [Indexed: 11/27/2022]
Abstract
In the new era of healthcare digitalization, there is a golden opportunity in the overlap between digital health and Real-World Evidence (RWE). In this commentary, we define RWE and digital health and investigate their intersection. We describe the stages in the RWE value chain critical to the evidence generation process, how these stages change with new digital technologies and the opportunities and challenges that arise from how these stages evolve—including their application for stakeholders such as patients, physicians and regulators. We also discuss the current published guidelines and frameworks regarding digital health. We categorise these publications in terms of their clarity as “Extensive”, “Intermediate” or “Basic” and according to whether they encompass all levels of digital health or are more focussed in their guidance. Finally, we provide recommendations to increase synergy between RWE and digital health.
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Ex vivo normothermic perfusion of isolated segmental porcine bowel: a novel functional model of the small intestine. BJS Open 2021; 5:6220254. [PMID: 33839750 PMCID: PMC8038264 DOI: 10.1093/bjsopen/zrab009] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 01/26/2021] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND There is an unmet need for suitable ex vivo large animal models in experimental gastroenterology and intestinal transplantation. This study details a reliable and effective technique for ex vivo normothermic perfusion (EVNP) of segmental porcine small intestine. METHODS Segments of small intestine, 1.5-3.0 m in length, were retrieved from terminally anaesthetized pigs. After a period of cold ischaemia, EVNP was performed for 2 h at 37°C with a mean pressure of 80 mmHg using oxygenated autologous blood diluted with Ringer's solution. The duration of EVNP was extended to 4 h for a second set of experiments in which two segments of proximal to mid-ileum (1.5-3.0 m) were retrieved from each animal and reperfused with whole blood (control) or leucocyte-depleted blood to examine the impact of leucocyte depletion on reperfusion injury. RESULTS After a mean cold ischaemia time of 5 h and 20 min, EVNP was performed in an initial group of four pigs. In the second set of experiments, five pigs were used in each group. In all experiments bowel segments were well perfused and exhibited peristalsis during EVNP. Venous glucose levels significantly increased following luminal glucose stimulation (mean(s.e.m.) basal level 1.8(0.6) mmol/l versus peak 15.5(5.8) mmol/l; P < 0.001) and glucagon-like peptide 1 (GLP-1) levels increased in all experiments, demonstrating intact absorptive and secretory intestinal functions. There were no significant differences between control and leucocyte-depleted animals regarding blood flow, venous glucose, GLP-1 levels or histopathology at the end of 4 h of EVNP. CONCLUSIONS This novel model is suitable for the investigation of gastrointestinal physiology, pathology and ischaemia reperfusion injury, along with evaluation of potential therapeutic interventions.
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Establishment of normative biometric data for body composition based on computed tomography in a North American cohort. Clin Nutr 2020; 40:2435-2442. [PMID: 33176926 DOI: 10.1016/j.clnu.2020.10.046] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 10/22/2020] [Accepted: 10/23/2020] [Indexed: 12/23/2022]
Abstract
BACKGROUND & AIMS Accurate and reproducible biomarkers are required to allow a more personalized approach to patient care. Body composition is one such biomarker affecting outcomes in a range of surgical and oncological conditions. The aim of this study is to determine the age and sex specific distribution of body composition data, based on information gathered from computed tomography (CT). METHODS This prospective study used healthy subjects from the medical records linkage of the Rochester Epidemiology Project, based in Minnesota, USA. Each patient had a CT scan without intravenous contrast performed between 1999 and 2001. Quantification was performed using previously validated semi-automated in-house developed software for body composition analysis. Subcutaneous adipose tissue area, visceral adipose tissue area, intermuscular adipose tissue area and skeletal muscle area were measured and indexed to subject height. Generalized Additive Models for Location, Scale and Shape were used to assess the location, scale, and shape of each variable across age, stratified by sex. Z-scores specific to sex were assessed for each of the parameters analyzed. Age-specific z-scores were calculated using the formula: Z = (Index Variable - μ)/σ or Z = (√ (Index Variable) - μ)/σ. RESULTS There were 692 subjects enrolled in the study. The fitted model equation was offered for each variable with values presented for μ and σ. Modelling with penalized splines was performed for VAT index, IMAT index and total adipose tissue index. Scatterplots of each variable were produced with lines of Z-scores as a visual representation. CONCLUSION This study offers comparative data to allow comparison amongst multiple populations. This will form an important reference for future research and clinical practice.
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Correction to: Bridging the Gap Between RCTs and RWE Through Endpoint Selection. Ther Innov Regul Sci 2020; 55:97. [PMID: 33128171 DOI: 10.1007/s43441-020-00225-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Risk of hydroxychloroquine alone and in combination with azithromycin in the treatment of rheumatoid arthritis: a multinational, retrospective study. LANCET RHEUMATOLOGY 2020; 2:e698-e711. [PMID: 32864627 PMCID: PMC7442425 DOI: 10.1016/s2665-9913(20)30276-9] [Citation(s) in RCA: 89] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Background Hydroxychloroquine, a drug commonly used in the treatment of rheumatoid arthritis, has received much negative publicity for adverse events associated with its authorisation for emergency use to treat patients with COVID-19 pneumonia. We studied the safety of hydroxychloroquine, alone and in combination with azithromycin, to determine the risk associated with its use in routine care in patients with rheumatoid arthritis. Methods In this multinational, retrospective study, new user cohort studies in patients with rheumatoid arthritis aged 18 years or older and initiating hydroxychloroquine were compared with those initiating sulfasalazine and followed up over 30 days, with 16 severe adverse events studied. Self-controlled case series were done to further establish safety in wider populations, and included all users of hydroxychloroquine regardless of rheumatoid arthritis status or indication. Separately, severe adverse events associated with hydroxychloroquine plus azithromycin (compared with hydroxychloroquine plus amoxicillin) were studied. Data comprised 14 sources of claims data or electronic medical records from Germany, Japan, the Netherlands, Spain, the UK, and the USA. Propensity score stratification and calibration using negative control outcomes were used to address confounding. Cox models were fitted to estimate calibrated hazard ratios (HRs) according to drug use. Estimates were pooled where the I 2 value was less than 0·4. Findings The study included 956 374 users of hydroxychloroquine, 310 350 users of sulfasalazine, 323 122 users of hydroxychloroquine plus azithromycin, and 351 956 users of hydroxychloroquine plus amoxicillin. No excess risk of severe adverse events was identified when 30-day hydroxychloroquine and sulfasalazine use were compared. Self-controlled case series confirmed these findings. However, long-term use of hydroxychloroquine appeared to be associated with increased cardiovascular mortality (calibrated HR 1·65 [95% CI 1·12-2·44]). Addition of azithromycin appeared to be associated with an increased risk of 30-day cardiovascular mortality (calibrated HR 2·19 [95% CI 1·22-3·95]), chest pain or angina (1·15 [1·05-1·26]), and heart failure (1·22 [1·02-1·45]). Interpretation Hydroxychloroquine treatment appears to have no increased risk in the short term among patients with rheumatoid arthritis, but in the long term it appears to be associated with excess cardiovascular mortality. The addition of azithromycin increases the risk of heart failure and cardiovascular mortality even in the short term. We call for careful consideration of the benefit-risk trade-off when counselling those on hydroxychloroquine treatment. Funding National Institute for Health Research (NIHR) Oxford Biomedical Research Centre, NIHR Senior Research Fellowship programme, US National Institutes of Health, US Department of Veterans Affairs, Janssen Research and Development, IQVIA, Korea Health Industry Development Institute through the Ministry of Health and Welfare Republic of Korea, Versus Arthritis, UK Medical Research Council Doctoral Training Partnership, Foundation Alfonso Martin Escudero, Innovation Fund Denmark, Novo Nordisk Foundation, Singapore Ministry of Health's National Medical Research Council Open Fund Large Collaborative Grant, VINCI, Innovative Medicines Initiative 2 Joint Undertaking, EU's Horizon 2020 research and innovation programme, and European Federation of Pharmaceutical Industries and Associations.
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Abstract
Quantitative computed tomography (QCT) based finite element (FE) models can compute subject-specific proximal femoral strengths, or fracture loads, that are associated with hip fracture risk. These fracture loads are more strongly associated with measured fracture loads than are DXA and QCT measures and are predictive of hip fracture independently of DXA bone mineral density (BMD). However, interpreting FE-computed fracture loads of younger subjects for the purpose of evaluating hip fracture risk in old age is challenging due to limited reference data. The goal of this study was to address this issue by providing reference data for male and female adult subjects of all ages. QCT-based FE models of the left proximal femur of 216 women and 181 men, age 27 to 90 years, from a cohort of Rochester, MN residents were used to compute proximal femoral load capacities, i.e. the maximum loads that can be supported, in single-limb stance and posterolateral fall loading (Stance_LC and Fall_LC, respectively) [US Patent No. 9,245,069] and yield load under fall loading (Fall_yield). To relate these measures to information about hip fracture, the CT scanner and calibration phantom were cross-calibrated with those from our previous prospective study of hip fracture in older fracture and control subjects, the Age Gene/Environment Susceptibility (AGES) Reykjavik cohort. We then plotted Stance_LC, Fall_LC and Fall_yield versus age for the two cohorts on the same graphs. Thus, proximal femoral strengths in individuals above 70 years of age can be assessed through direct comparison with the FE data from the AGES cohort which were analyzed using identical methods. To evaluate younger individuals, reductions in Stance_LC, Fall_LC and Fall_yield from the time of evaluation to age 70 years can be cautiously estimated from the average yearly cross-sectional decreases found in this study (108 N, 19.4 N and 14.4 N, respectively, in men and 120 N, 19.4 N and 21.6 N, respectively, in women), and the projected fracture loads can be compared with data from the AGES cohort. Although we did not set specific thresholds for identifying individuals at risk of hip fracture, these data provide some guidance and may be used to help establish diagnostic criteria in future. Additionally, given that these data were nearly entirely from Caucasian subjects, future research involving subjects of other races/ethnicities is necessary.
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Bridging the Gap Between RCTs and RWE Through Endpoint Selection. Ther Innov Regul Sci 2020; 55:90-96. [PMID: 32632753 PMCID: PMC7785541 DOI: 10.1007/s43441-020-00193-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 06/23/2020] [Indexed: 11/23/2022]
Abstract
This commentary is authored by several industry real-world evidence (RWE) experts, with support from IQVIA, as part of the 'RWE Leadership Forum': a group of Industry Leaders who have come together as non-competitive partners to understand and respond to RWD/E challenges and opportunities with a single expert voice. Here, the forum discusses the value in bridging the industry disconnect between RTCs and RWE, with a view to promoting the use of RWE in the RCT environment. RCT endpoints are explored along several axes including their clinical relevance and their measure of direct patient benefit, and then compared with their real-world counterparts to identify suitable paths, or gaps, for assimilating RWE endpoints into the RCT environment.
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Biomechanical Computed Tomography analysis (BCT) for clinical assessment of osteoporosis. Osteoporos Int 2020; 31:1025-1048. [PMID: 32335687 PMCID: PMC7237403 DOI: 10.1007/s00198-020-05384-2] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Accepted: 03/09/2020] [Indexed: 12/12/2022]
Abstract
The surgeon general of the USA defines osteoporosis as "a skeletal disorder characterized by compromised bone strength, predisposing to an increased risk of fracture." Measuring bone strength, Biomechanical Computed Tomography analysis (BCT), namely, finite element analysis of a patient's clinical-resolution computed tomography (CT) scan, is now available in the USA as a Medicare screening benefit for osteoporosis diagnostic testing. Helping to address under-diagnosis of osteoporosis, BCT can be applied "opportunistically" to most existing CT scans that include the spine or hip regions and were previously obtained for an unrelated medical indication. For the BCT test, no modifications are required to standard clinical CT imaging protocols. The analysis provides measurements of bone strength as well as a dual-energy X-ray absorptiometry (DXA)-equivalent bone mineral density (BMD) T-score at the hip and a volumetric BMD of trabecular bone at the spine. Based on both the bone strength and BMD measurements, a physician can identify osteoporosis and assess fracture risk (high, increased, not increased), without needing confirmation by DXA. To help introduce BCT to clinicians and health care professionals, we describe in this review the currently available clinical implementation of the test (VirtuOst), its application for managing patients, and the underlying supporting evidence; we also discuss its main limitations and how its results can be interpreted clinically. Together, this body of evidence supports BCT as an accurate and convenient diagnostic test for osteoporosis in both sexes, particularly when used opportunistically for patients already with CT. Biomechanical Computed Tomography analysis (BCT) uses a patient's CT scan to measure both bone strength and bone mineral density at the hip or spine. Performing at least as well as DXA for both diagnosing osteoporosis and assessing fracture risk, BCT is particularly well-suited to "opportunistic" use for the patient without a recent DXA who is undergoing or has previously undergone CT testing (including hip or spine regions) for an unrelated medical condition.
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Machine learning imputation of Eastern Cooperative Oncology Group performance status (ECOG PS) scores from data in CancerLinQ discovery. J Clin Oncol 2020. [DOI: 10.1200/jco.2020.38.15_suppl.e19318] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
e19318 Background: ECOG PS is a prognostic indicator of outcomes, and scores of 0-1 (good ECOG PS) are often required for clinical trial enrollment. Patients treated in non-trial settings often lack ECOG PS scores limiting the ability of Real World Data from these patients to be used in external control arms (ECAs) or to provide optimal specificity for clinical effectiveness research. Machine Learning can be used to impute ECOG PS scores from other clinical data at various points during treatment. Methods: We developed a series of models using logistic regression (LR) or XGBoost (XGB) that impute ECOG PS at initial diagnosis, metastatic diagnosis and final evaluation using a curated Non-Small Cell Lung Cancer cohort of 31,425 patients with at least one ECOG PS score. Results: AUC-ROC values of up to 0.81 could be obtained for imputing a patient’s final ECOG PS, with lower AUC values when imputing ECOG PS at initial and metastatic diagnosis using large numbers (i.e. thousands) of features. We developed more interpretable models with 110 or 40 features with reduced but still satisfactory AUC, with accuracy of predicting good ECOG PS scores of around 80%. Key features were obtained from lab tests, physical exams, comorbidities, medications, age and metastatic status. The table below shows the results of several of these models. Where the models misclassify ECOG PS, the error was rarely greater than 1 grade. Conclusions: ECOG PS is subjective, suggesting that ML based cohort assignment will be sufficiently accurate to support their use in research. Further work will be required to assess if the ML predicted cohorts have different outcomes. [Table: see text]
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Durability of glycaemic control in patients with type 2 diabetes after metformin failure: Prognostic model derivation and validation using the DISCOVER study. Diabetes Obes Metab 2020; 22:828-837. [PMID: 31944528 DOI: 10.1111/dom.13966] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 01/03/2020] [Accepted: 01/12/2020] [Indexed: 12/23/2022]
Abstract
AIM To develop and internally validate prognostic models on the long-term durability of glycaemic control in patients with type 2 diabetes after metformin failure. MATERIALS AND METHODS DISCOVER is a 3-year, prospective observational study across six continents investigating second-line glucose-lowering therapies. In this analysis from 35 countries, we included patients on metformin initiating second-line glucose-lowering medication(s) because of physician-defined lack of efficacy. The outcome was durability of glycaemic control, defined as three consecutive levels of HbA1c at 6-, 12- and 24-month follow-up at target (HbA1c equal to or lower than the level when the physician initiated the second-line therapy in patients with baseline HbA1c ≤7% [53 mmol/mol]; and equal to or lower than 7% in those with baseline HbA1c >7%). We developed and internally validated two prognostic models: a base model, which included age, sex, ethnicity, country income group, baseline HbA1c and second-line therapy, and an advanced model, established through statistical variable selections from a model including base variables and 13 additional predictors selected from a literature review. We used logistic regression to develop and 500 bootstrapping samples to internally validate the models; discrimination and calibration were used to assess model performance. RESULTS Overall, 896 out of 2995 participants (29.9%) had sustained glycaemic control. The base model performed well: Nagelkerke R2 was 0.13, C-index 0.70 (95% CI: 0.68, 0.71) and bias-corrected C-index 0.69 after internal validation. Diabetes duration, insurance type, estimated glomerular filtration rate and glucose self-monitoring were additionally selected in the advanced model, which had only a slightly better performance compared with the base model: Nagelkerke R2 0.20, C-index 0.71 (95% CI: 0.69, 0.73) and bias-corrected C-index 0.70. Calibration plots showed good calibrations of both validated models. CONCLUSION These prognostic models, which include simple demographic and routinely collected clinical information, enabled the estimation of the probability of 2-year sustained glycaemic control in patients after metformin failure. The models have been implemented into a web-based tool to support healthcare professionals in their decisions.
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Strengthening pharma's contract with society: the value of trusted partnerships between pharma and healthcare facilitated by real-world data. J Comp Eff Res 2020; 9:155-159. [DOI: 10.2217/cer-2019-0183] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
This White Paper is authored by 11 industry real-world evidence (RWE) experts, with support from IQVIA, as part of the ‘RWE Leadership Forum’: a group of industry leaders who come together as noncompetitive partners to understand and respond to internal or external RWD/E challenges and opportunities with a single expert voice. Herein we aim to clarify the rules of engagement between pharma and healthcare in order to establish trust-based partnerships, which will unlock unique value for society, including the medical community and the ultimate beneficiary, the patient.
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Dysphagia in Parkinson's Disease Improves with Vocal Augmentation. Dysphagia 2019; 34:862-868. [PMID: 30694413 DOI: 10.1007/s00455-019-09982-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Accepted: 01/18/2019] [Indexed: 12/26/2022]
Abstract
While voice-related disorders in Parkinson's disease (PD) are commonly discussed in the literature, dysphagia in PD is less widely published. Vocal fold augmentation, including injection laryngoplasty (IL), is a well-established treatment for glottal insufficiency (Cates et al. in Otolaryngol Head Neck Surg 155(3):454-457, 2016). This study aimed to observe the effects of IL in PD patients with vocal bowing, with or without therapy, on glottic closure and patient-reported dysphagia outcomes. The study design was based on retrospectively collected database and cohort-case series. PD patients selected for retrospective review over a 2-year period were referred and evaluated in the Voice, Swallowing, and Airway multidisciplinary clinic by speech language pathologist and laryngologist, and were undergoing IL. Charts were reviewed for age, gender, Body Mass Index (BMI), onset of PD, and Movement Disorders Society-Unified Parkinson's Disease Rating Scale Part 3 (MDS-UPDRS) scoring. We compared pre/postoperatively (> 1 < 3 months) using validated patient-reported outcome tools: Reflux Symptom Index (RSI), Glottal Function Index (GFI), Eating Assessment Tool-10 (EAT), and stroboscopic examinations. The study included 14 patients undergoing 22 IL or 1.6 IL/patient: mean age 70 years (63-80), 100% male, and BMI 25.9 ± 4.3 (mean ± SD). MDS-UPDRS scoring 33 ± 20 (moderate severity), with time between PD diagnosis and IL 8 ± 10 years. All patients had pre- and post-stroboscopic examinations; however, only 4:14 underwent formal swallowing evaluation. Overall, 14 IL patients improved on patient-reported measures (ΔRSI = 4; ΔGFI = 3; ΔEAT = 4). Based on the findings of the study, we conclude that PD is a progressive neurodegenerative condition with dysphagia. The presented pilot data suggest that IL may be considered as a beneficial adjunct for PD patients with glottal insufficiency. LEVEL OF EVIDENCE: 4.
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Staging laparoscopy in oesophagogastric malignancy: Our experience of its impact on patient management. Int J Surg 2018. [DOI: 10.1016/j.ijsu.2018.05.566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Real world evidence (RWE) - a disruptive innovation or the quiet evolution of medical evidence generation? F1000Res 2018; 7:111. [PMID: 30026923 PMCID: PMC6039945 DOI: 10.12688/f1000research.13585.1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/24/2018] [Indexed: 11/08/2023] Open
Abstract
Stakeholders in healthcare are increasingly turning to real world evidence (RWE) to inform their decisions, alongside evidence from randomized controlled trials. RWE is generated by analysing data gathered from routine clinical practice, and can be used across the product lifecycle, providing insights into areas including disease epidemiology, treatment effectiveness and safety, and health economic value and impact. Recently, the US Food and Drug Administration and the European Medicines Agency have stated their ambition for greater use of RWE to support applications for new indications, and are now consulting with their stakeholders to formalize standards and expected methods for generating RWE. Pharmaceutical companies are responding to the increasing demands for RWE by developing standards and processes for each stage of the evidence generation pathway. Some conventions are already in place for assuring quality, whereas other processes are specific to the research question and data sources available. As evidence generation increasingly becomes a core role of medical affairs divisions in large pharmaceutical companies, standards of rigour will continue to evolve and improve. Senior pharmaceutical leaders can drive this change by making RWE a core element of their corporate strategy, providing top-level direction on how their respective companies should approach RWE for maximum quality. Here, we describe the current and future areas of RWE application within the pharmaceutical industry, necessary access to data to generate RWE, and the challenges in communicating RWE. Supporting and building on viewpoints from industry and publicly funded research, our perspective is that at each stage of RWE generation, quality will be critical to the impact that RWE has on healthcare decision-makers; not only where RWE is an established and evolving tool, but also in new areas that have the potential to disrupt and to improve drug development pathways.
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Abstract
Stakeholders in healthcare are increasingly turning to real world evidence (RWE) to inform their decisions, alongside evidence from randomized controlled trials. RWE is generated by analysing data gathered from routine clinical practice, and can be used across the product lifecycle, providing insights into areas including disease epidemiology, treatment effectiveness and safety, and health economic value and impact. Recently, the US Food and Drug Administration and the European Medicines Agency have stated their ambition for greater use of RWE to support applications for new indications, and are now consulting with their stakeholders to formalize standards and expected methods for generating RWE. Pharmaceutical companies are responding to the increasing demands for RWE by developing standards and processes for each stage of the evidence generation pathway. Some conventions are already in place for assuring quality, whereas other processes are specific to the research question and data sources available. As evidence generation increasingly becomes a core role of medical affairs divisions in large pharmaceutical companies, standards of rigour will continue to evolve and improve. Senior pharmaceutical leaders can drive this change by making RWE a core element of their corporate strategy, providing top-level direction on how their respective companies should approach RWE for maximum quality. Here, we describe the current and future areas of RWE application within the pharmaceutical industry, necessary access to data to generate RWE, and the challenges in communicating RWE. Supporting and building on viewpoints from industry and publicly funded research, our perspective is that at each stage of RWE generation, quality will be critical to the impact that RWE has on healthcare decision-makers; not only where RWE is an established and evolving tool, but also in new areas that have the potential to disrupt and to improve drug development pathways.
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The impact of the new National Bone Health Alliance (NBHA) diagnostic criteria on the prevalence of osteoporosis in the United States: supplementary presentation. Osteoporos Int 2017; 28:3283-3284. [PMID: 28936598 DOI: 10.1007/s00198-017-4207-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2017] [Accepted: 03/09/2017] [Indexed: 10/18/2022]
Abstract
We evaluated the prevalence of osteoporosis using the osteoporosis diagnostic criteria developed by the National Bone Health Alliance (NBHA), which includes qualified fractures, FRAX score in addition to BMD. The expanded definition increases the prevalence compared to BMD alone definitions; however, it may better identify those at elevated fracture risk. Recently an NBHA working Group published a paper in OI with recommendations for expanding the criteria that would constitute an osteoporosis diagnosis in postmenopausal women and in men over age 50 for use in the US - Siris et al., Osteoporosis International 25(%): 1439-1443, 2014. The recommendations have now been endorsed by NOF, ASBMR and a number of professional medical groups and appear in the NOF Clinician's Guide. The new diagnostic criteria continue to include a T-score by DXA of spine or hip that is less than or equal to -2.5, but alternatively also include a hip fracture with or without BMD testing or a vertebral, pelvis, proximal humerus and in some cases a distal forearm fracture in a person with low bone mass, or a FRAX score that meets or exceeds the NOF Guide osteoporosis treatment cut point.
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Implementation of Dedicated Barrett's Oesophagus Endoscopic Diagnostic and Surveillance Lists in a District General Hospital. Int J Surg 2017. [DOI: 10.1016/j.ijsu.2017.08.458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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The comparability of HR-pQCT bone measurements is improved by scanning anatomically standardized regions. Osteoporos Int 2017; 28:2115-2128. [PMID: 28391447 PMCID: PMC5526099 DOI: 10.1007/s00198-017-4010-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 03/13/2017] [Indexed: 12/16/2022]
Abstract
UNLABELLED We investigated the sensitivity of distal bone density, structure, and strength measurements by high-resolution peripheral quantitative computed tomography (HR-pQCT) to variability in limb length. Our results demonstrate that HR-pQCT should be performed at a standard %-of-total-limb-length to avoid substantial measurement bias in population study comparisons and the evaluation of individual skeletal status in a clinical context. INTRODUCTION High-resolution peripheral quantitative computed tomography (HR-pQCT) measures of bone do not account for anatomic variability in bone length: a 1-cm volume is acquired at a fixed offset from an anatomic landmark. Our goal was to evaluate HR-pQCT measurement variability introduced by imaging fixed vs. proportional volumes and to propose a standard protocol for relative anatomic positioning. METHODS Double-length (2-cm) scans were acquired in 30 adults. We compared measurements from 1-cm sub-volumes located at the default fixed offset, and the average %-of-length offset. The average position corresponded to 4.0% ± 1.1 mm for radius, and 7.2% ± 2.2 mm for tibia. We calculated the RMS difference in bone parameters and T-scores to determine the measurement variability related to differences in limb length. We used anthropometric ratios to estimate the mean limb length for published HR-pQCT reference data, and then calculated mean %-of-length offsets. RESULTS Variability between fixed vs. relative scan positions was highest in the radius, and for cortical bone in general (RMS difference Ct.Th = 19.5%), while individuals had T-score differentials as high as +3.0 SD (radius Ct.BMD). We estimated that average scan position for published HR-pQCT reference data corresponded to 4.0% at the radius, and 7.3% at tibia. CONCLUSION Variability in limb length introduces significant bias to HR-pQCT measures, confounding cross-sectional analyses and limiting the clinical application for individual assessment of skeletal status. We propose to standardize scan positioning using 4.0 and 7.3% of total bone length for the distal radius and tibia, respectively.
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The application of electronic medical records (EMRs) as a virtual comparator arm in a lung cancer clinical trial: A case study. J Clin Oncol 2017. [DOI: 10.1200/jco.2017.35.15_suppl.e18098] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
e18098 Background: Single-arm and open-label clinical studies are common in oncology drug development, leading to a frequent need for contextualization of results and provision of other means of comparison for cost-effectiveness models. The utility of current approaches such as naïve comparisons, historical control benchmarking, and match-adjusted interventional controls is limited. An alternative approach is the use of routinely collected data from Electronic Medical Records (EMRs). This study sought to determine if overall survival (OS) in advanced non-small cell lung cancer patients from a clinical trial comparator arm could be replicated using EMR data. Methods: De-identified EMR-derived patient data from Flatiron Health were matched via propensity scores to Project Data Sphere clinical trial data for study NCT00457392 of sunitinib plus erlotinib versus erlotinib alone to compare overall survival outcomes. A Cox regression model stratified for dataset was used to estimate the hazard ratio and 95% confidence interval for OS. Results: The Kaplan Meier curves were comparable for the first period after start of treatment, but differed after median survival was reached, with the Flatiron dataset achieving longer median OS. This deviation was strongly associated with differences in post-erlotinib treatment options introduced between the clinical trial period and the EMR period. Splitting the Flatiron data in two, related to the period from which the data were obtained (pre- or post-2013), resulted in a better match for the period closer to the trial [HR: 1.12 (0.93,1.35), P = 0.219] than for the later period [HR: 1.23 (1.01,1.5), P = 0.039]. Conclusions: Our results demonstrate that the time period in which EMR data are collected is important when matching to trial data. EMR data can contextualize the OS benefit for single-arm or uncontrolled trials run in the same time period. Further exploration of time-varying effects on OS is warranted.
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The impact of the new National Bone Health Alliance (NBHA) diagnostic criteria on the prevalence of osteoporosis in the USA. Osteoporos Int 2017; 28:1225-1232. [PMID: 27966104 DOI: 10.1007/s00198-016-3865-3] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 11/30/2016] [Indexed: 01/03/2023]
Abstract
UNLABELLED We evaluated the prevalence of osteoporosis using the osteoporosis diagnostic criteria developed by the National Bone Health Alliance (NBHA), which includes qualified fractures, FRAX score in addition to bone mineral density (BMD). The expanded definition increases the prevalence compared to BMD alone definitions; however, it may better identify those at elevated fracture risk. PURPOSE The purpose of this paper is to estimate the prevalence of osteoporosis in US adults ≥50 years using the NBHA osteoporosis diagnostic criteria. METHODS Utilizing 2005-2008 data of the National Health and Nutrition Examination Survey (NHANES), we identified participants with osteoporosis with any one of the following: (1) femoral neck or lumbar spine T-score ≤ -2.5; (2) low trauma hip fracture irrespective of BMD or clinical vertebral, proximal humerus, pelvis, or distal forearm fracture with a T-score >-2.5 <-1.0; or (3) FRAX score at the National Osteoporosis Foundation intervention thresholds (≥3% for hip fracture or ≥20% for major osteoporotic fracture). We estimated the prevalence overall and by gender and age. RESULTS Our sample included 1948 (54.3%) men and 1639 (45.7%) women. Approximately 12% were 80+ years and 21% were from racial/ethnic minority groups. We estimated that 16.0% (0.8) of men and 29.9% (1.0) of women 50+ years have osteoporosis. The prevalence increases with age to 46.3% in men and 77.1% in women 80+ years. The combination of FRAX score and fractures was the largest contributing factor defining osteoporosis in men (70-79, 88.1%; 80+, 80.1%), whereas T-score was the largest contributing factor in women (70-79, 49.2%; 80+, 43.5%). CONCLUSIONS We found that 16% of men and 29.9% of women 50+ have osteoporosis based on the NBHA diagnostic criteria. Although the expanded definition increases the prevalence compared to BMD alone-based definitions, it may better identify those at elevated fracture risk in order to reduce the burden of fractures in older adults.
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Operator variability in scan positioning is a major component of HR-pQCT precision error and is reduced by standardized training. Osteoporos Int 2017; 28:245-257. [PMID: 27475931 PMCID: PMC5568957 DOI: 10.1007/s00198-016-3705-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 07/07/2016] [Indexed: 02/02/2023]
Abstract
UNLABELLED In this study, we determined that operator positioning precision contributes significant measurement error in high-resolution peripheral quantitative computed tomography (HR-pQCT). Moreover, we developed software to quantify intra- and inter-operator variability and demonstrated that standard positioning training (now available as a web-based application) can significantly reduce inter-operator variability. INTRODUCTION HR-pQCT is increasingly used to assess bone quality, fracture risk, and anti-fracture interventions. The contribution of the operator has not been adequately accounted in measurement precision. Operators acquire a 2D projection ("scout view image") and define the region to be scanned by positioning a "reference line" on a standard anatomical landmark. In this study, we (i) evaluated the contribution of positioning variability to in vivo measurement precision, (ii) measured intra- and inter-operator positioning variability, and (iii) tested if custom training software led to superior reproducibility in new operators compared to experienced operators. METHODS To evaluate the operator in vivo measurement precision, we compared precision errors calculated in 64 co-registered and non-co-registered scan-rescan images. To quantify operator variability, we developed software that simulates the positioning process of the scanner's software. Eight experienced operators positioned reference lines on scout view images designed to test intra- and inter-operator reproducibility. Finally, we developed modules for training and evaluation of reference line positioning. We enrolled six new operators to participate in a common training, followed by the same reproducibility experiments performed by the experienced group. RESULTS In vivo precision errors were up to threefold greater (Tt.BMD and Ct.Th) when variability in scan positioning was included. The inter-operator precision errors were significantly greater than the short-term intra-operator precision (p < 0.001). New trained operators achieved comparable intra-operator reproducibility to experienced operators and lower inter-operator reproducibility (p < 0.001). Precision errors were significantly greater for the radius than for the tibia. CONCLUSION Operator reference line positioning contributes significantly to in vivo measurement precision and is significantly greater for multi-operator datasets. Inter-operator variability can be significantly reduced using a systematic training platform, now available online ( http://webapps.radiology.ucsf.edu/refline/ ).
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Technical note: Recommendations for a standard procedure to assess cortical bone at the tissue-level in vivo using impact microindentation. Bone Rep 2016; 5:181-185. [PMID: 27975078 PMCID: PMC5152622 DOI: 10.1016/j.bonr.2016.07.004] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Impact microindentation is a novel method for measuring the resistance of cortical bone to indentation in patients. Clinical use of a handheld impact microindentation technique is expanding, highlighting the need to standardize the measurement technique. Here, we describe a detailed standard operation procedure to improve the consistency and comparability of the measurements across centers. A protocol for impact microindentation in clinics is described. Measurements can be standardized by adopting a common protocol. The aim of the work is to minimize the inter-center variability. This protocol reflects the experience of the 7 involved centers.
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Response of greenhouse mini-cucumber to different vertical spectra of LED lighting under overhead high pressure sodium and plasma lighting. ACTA ACUST UNITED AC 2016. [DOI: 10.17660/actahortic.2016.1134.12] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Novel anthropomorphic hip phantom corrects systemic interscanner differences in proximal femoral vBMD. Phys Med Biol 2016; 59:7819-34. [PMID: 25419618 DOI: 10.1088/0031-9155/59/24/7819] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Quantitative computed tomography (QCT) is increasingly used in osteoporosis studies to assess volumetric bone mineral density (vBMD), bone quality and strength. However, QCT is confronted by technical issues in the clinical research setting, such as potentially confounding effects of body size on vBMD measurements and lack of standard approaches to scanner cross-calibration, which affects measurements of vBMD in multicenter settings. In this study, we addressed systematic inter-scanner differences and subject-dependent body size errors using a novel anthropomorphic hip phantom, containing a calibration hip to estimate correction equations, and a contralateral test hip to assess the quality of the correction. We scanned this phantom on four different scanners and we applied phantom-derived corrections to in vivo images of 16 postmenopausal women scanned on two scanners. From the phantom study, we found that vBMD decreased with increasing phantom size in three of four scanners and that inter-scanner variations increased with increasing phantom size. In the in vivo study, we observed that inter-scanner corrections reduced systematic inter-scanner mean vBMD differences but that the inter-scanner precision error was still larger than expected from known intra-scanner precision measurements. In conclusion, inter-scanner corrections and body size influence should be considered when measuring vBMD from QCT images.
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Can vitamin D metabolite measurements facilitate a "treat-to-target" paradigm to guide vitamin D supplementation? Osteoporos Int 2015; 26:1655-60. [PMID: 25572049 PMCID: PMC4412341 DOI: 10.1007/s00198-014-3010-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Accepted: 12/15/2014] [Indexed: 10/24/2022]
Abstract
UNLABELLED Substantial variability exists in the serum 25(OH)D increase observed in response to vitamin D supplementation. Measurement of circulating cholecalciferol and 24,25(OH)₂D, as indicators of vitamin D absorption and degradation, respectively, account for approximately half of the variation in serum 25(OH)D observed following supplementation. INTRODUCTION Vitamin D supplementation produces a variable response in serum 25(OH)D. This variability likely reflects, in part, differences in vitamin D absorption and/or degradation. Despite this variation in response, virtually all expert recommendations endorse a fixed vitamin D supplementation dose, an approach also used in most prospective studies. Such utilization of a single vitamin D dose does not assure attaining any pre-specified target 25(OH)D level, thereby compromising clinical care and prospective supplementation trials. This study begins addressing this weakness by exploring the feasibility of vitamin D metabolite measurements to predict serum 25(OH)D level attained following supplementation. METHODS Ninety-one community-dwelling postmenopausal women with baseline 25(OH)D of 10-30 ng/mL received oral vitamin D₃, 2300 or 2500 IU, daily for 4-6 months. Serum 25(OH)D, cholecalciferol (D₃), and 24,25(OH)₂D were measured before and at the end of supplementation to determine if metabolite concentrations allow prediction of the 25(OH)D level attained. RESULTS From baseline and follow-up data, we derived a multiple linear regression model predicting posttreatment 25(OH)D as follows: final 25(OH)D = 8.3 + (1.05*initial 25(OH)D) - (7.7*initial 24,25(OH)₂D) + (0.53*final D₃) + (4.2*final 24,25(OH)₂D). This model has an adjusted R(2) = 0.55, thus accounting for approximately half of the observed variance in the final 25(OH)D level. CONCLUSIONS The contributions of circulating cholecalciferol and 24,25(OH)₂D to this predictive model can be considered as indicators of intestinal absorption and clearance, respectively. This paradigm requires further study; it may allow efficient "treat-to-25(OH)D-target" strategies useful in optimizing prospective studies and clinical practice.
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Meta-Analysis of Peak Wall Stress in Ruptured, Symptomatic, and Intact Abdominal Aortic Aneurysms. J Vasc Surg 2015. [DOI: 10.1016/j.jvs.2015.01.021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Meta-analysis of peak wall stress in ruptured, symptomatic and intact abdominal aortic aneurysms. Br J Surg 2014; 101:1350-7; discussion 1357. [PMID: 25131598 DOI: 10.1002/bjs.9578] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2014] [Accepted: 04/30/2014] [Indexed: 02/04/2023]
Abstract
BACKGROUND Abdominal aortic aneurysm (AAA) is an important cause of sudden death; however, there are currently incomplete means to predict the risk of AAA rupture. AAA peak wall stress (PWS) can be estimated using finite element analysis (FEA) methods from computed tomography (CT) scans. The question is whether AAA PWS can predict AAA rupture. The aim of this systematic review was to compare PWS in patients with ruptured and intact AAA. METHODS The MEDLINE database was searched on 25 May 2013. Case-control studies assessing PWS in asymptomatic intact, and acutely symptomatic or ruptured AAA from CT scans using FEA were included. Data were extracted independently. A random-effects model was used to calculate standard mean differences (SMDs) for PWS measurements. RESULTS Nine studies assessing 348 individuals were identified and used in the meta-analysis. Results from 204 asymptomatic intact and 144 symptomatic or ruptured AAAs showed that PWS was significantly greater in the symptomatic/ ruptured AAAs compared with the asymptomatic intact AAAs (SMD 0·95, 95 per cent confidence interval 0·71 to 1·18; P < 0·001). The findings remained significant after adjustment for mean systolic blood pressure, standardized at 120 mmHg (SMD 0·68, 0·39 to 0·96; P < 0·001). Minimal heterogeneity between studies was noted (I(2) = 0 per cent). CONCLUSION This study suggests that PWS is greater in symptomatic or ruptured AAA than in asymptomatic intact AAA.
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The clinical diagnosis of osteoporosis: a position statement from the National Bone Health Alliance Working Group. Osteoporos Int 2014; 25:1439-43. [PMID: 24577348 PMCID: PMC3988515 DOI: 10.1007/s00198-014-2655-z] [Citation(s) in RCA: 368] [Impact Index Per Article: 36.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Accepted: 02/11/2014] [Indexed: 12/13/2022]
Abstract
UNLABELLED Osteoporosis causes an elevated fracture risk. We propose the continued use of T-scores as one means for diagnosis but recommend that, alternatively, hip fracture; osteopenia-associated vertebral, proximal humerus, pelvis, or some wrist fractures; or FRAX scores with ≥3% (hip) or 20% (major) 10-year fracture risk also confer an osteoporosis diagnosis. INTRODUCTION Osteoporosis is a common disorder of reduced bone strength that predisposes to an increased risk for fractures in older individuals. In the USA, the standard criterion for the diagnosis of osteoporosis in postmenopausal women and older men is a T-score of ≤ -2.5 at the lumbar spine, femur neck, or total hip by bone mineral density testing. METHODS Under the direction of the National Bone Health Alliance, 17 clinicians and clinical scientists were appointed to a working group charged to determine the appropriate expansion of the criteria by which osteoporosis can be diagnosed. RESULTS The group recommends that postmenopausal women and men aged 50 years should be diagnosed with osteoporosis if they have a demonstrable elevated risk for future fractures. This includes having a T-score of less than or equal to -2.5 at the spine or hip as one method for diagnosis but also permits a diagnosis for individuals in this population who have experienced a hip fracture with or without bone mineral density (BMD) testing and for those who have osteopenia by BMD who sustain a vertebral, proximal humeral, pelvic, or, in some cases, distal forearm fracture. Finally, the term osteoporosis should be used to diagnose individuals with an elevated fracture risk based on the World Health Organization Fracture Risk Algorithm, FRAX. CONCLUSIONS As new ICD-10 codes become available, it is our hope that this new understanding of what osteoporosis represents will allow for an appropriate diagnosis when older individuals are recognized as being at an elevated risk for fracture.
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Sexual risk behaviors and prevalence of sexually transmitted diseases in a cohort of Dominican men who have sex with men. Int J Infect Dis 2014. [DOI: 10.1016/j.ijid.2014.03.1296] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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Isolation and characterization of human osteoblasts from needle biopsies without in vitro culture. Osteoporos Int 2014; 25:887-95. [PMID: 24114401 PMCID: PMC4216562 DOI: 10.1007/s00198-013-2529-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Accepted: 09/25/2013] [Indexed: 11/28/2022]
Abstract
SUMMARY We isolate and characterize osteoblasts from humans without in vitro culture. These techniques should be broadly applicable to studying the pathogenesis of osteoporosis and other bone disorders. INTRODUCTION There is currently no data regarding the expression of specific genes or pathways in human osteoblasts that have not been subjected to extensive in vitro culture. Thus, we developed methods to rapidly isolate progressively enriched osteoblast populations from humans and characterized these cells. METHODS Needle bone biopsies of the posterior iliac crest were subjected to sequential collagenase digests. The cells from the second digest were stained with an alkaline phosphatase (AP) antibody, and the AP+ cells were isolated using magnetic cell sorting. RESULTS Relative to AP- cells, the AP+ cells contained virtually all of the mineralizing cells and were enriched for key osteoblast marker genes. The AP+ cells were further purified by depletion of cells expressing CD45, CD34, or CD31 (AP+/CD45/34/31- cells), which represented a highly enriched human osteoblast population devoid of hematopoietic/endothelial cells. These cells expressed osteoblast marker genes but very low to undetectable levels of SOST. We next used high-throughput RNA sequencing to compare the transcriptome of the AP+/CD45/34/31- cells to human fibroblasts and identified genes and pathways expressed only in human osteoblasts in vivo, but not in fibroblasts, including 448 genes unique to human osteoblasts. CONCLUSIONS We provide a detailed characterization of highly enriched human osteoblast populations without in vitro culture. These techniques should be broadly applicable to studying the pathogenesis of osteoporosis and other bone disorders.
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Mortality after pediatric kidney transplantation in England--a population-based cohort study. Pediatr Transplant 2014; 18:16-22. [PMID: 24134627 DOI: 10.1111/petr.12173] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/11/2013] [Indexed: 11/27/2022]
Abstract
The aim of this study was to explore mortality after pediatric kidney transplantation in England over the last decade. We used data from HES to select all kidney transplant procedures performed in England between April 2001 and March 2012. Data linkage analysis was performed with the ONS to identify all deaths occurring among this study cohort. Data for 1189 pediatric recipients were compared to 17 914 adult recipients (number of deaths, 33 vs. 2052, respectively, p < 0.001), with median follow-up 4.4 yr (interquartile range 2.2-7.3 yr). There was no difference in mortality within the pediatric cohort; age 0-1 (n = 25, patient survival 100.0%), age 2-5 (n = 198, patient survival 96.0%), age 6-12 (n = 359, patient survival 97.5%), and age 13-18 (n = 607, patient survival 97.4%), respectively (p = 0.567). The most common causes of death were renal (n = 8, 24.2%), infection (n = 6, 18.2%), and malignancy (n = 5, 15.2%). All deaths from malignancy were secondary to PTLD. In a fully adjusted Cox regression model, only white ethnicity was significantly associated with risk of pediatric mortality post-kidney transplantation (hazard ratio 2.7, 95% confidence interval [1.0-7.3], p = 0.047). To conclude, this population-based cohort study confirms low mortality after pediatric kidney transplantation with short follow-up.
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Death within the first year after kidney transplantation--an observational cohort study. Transpl Int 2013; 27:262-70. [PMID: 24138318 DOI: 10.1111/tri.12218] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Revised: 08/20/2013] [Accepted: 10/16/2013] [Indexed: 12/13/2022]
Abstract
The risk of death within the first year postkidney transplantation is not well described in the contemporary era. We extracted data on all kidney transplant procedures performed in England between April 2001 and March 2012. Data linkage analysis was performed between Hospital Episode Statistics and the Office for National Statistics to identify all deaths. Cox proportional hazard models were performed to identify factors associated with 1-year mortality. 566 deaths (3.0%) occurred within the first year post-transplant (from 19,103 kidney transplant procedures analysed). Infection, cardiovascular events and malignancy were classified in 21.6%, 18.3% and 7.4% of death certificates, respectively. Among recipients with prior myocardial infarct history who died within the first year, 38.8% of deaths were attributed to a cardiac-related event. Malignancy-related death was responsible for 61.5% of 1-year mortality for allograft recipients with pretransplant cancer history. 22.1% of deaths included kidney failure as a contributory factor on the death certificate (3.3% specifically stated allograft failure). Variables associated with 1-year mortality included deceased-donor kidney, increasing age, residence in socioeconomically deprived area and history of select medical comorbidities pre-operatively. We conclude 1-year mortality postkidney transplantation is low, but in select allograft recipients, the risk of death increases considerably.
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Socioeconomic deprivation is independently associated with mortality post kidney transplantation. Kidney Int 2013; 84:803-9. [DOI: 10.1038/ki.2013.176] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Revised: 02/21/2013] [Accepted: 03/01/2013] [Indexed: 11/09/2022]
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Can we update the Summary Hospital Mortality Index (SHMI) to make a useful measure of the quality of hospital care? An observational study. BMJ Open 2013; 3:bmjopen-2012-002018. [PMID: 23370014 PMCID: PMC3563139 DOI: 10.1136/bmjopen-2012-002018] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
OBJECTIVE To advance methods for the estimation of hospital performance based upon mortality ratios. DESIGN Observational study estimating trust performance in a year derived according to comparative standards from a 3-year period, accounting for patient-level case-mix and overdispersion (unexplained variability). PARTICIPANTS 23 363 630 admissions to the English National Health Service (NHS) by NHS Trust. MAIN OUTCOME MEASURES Number of SDs (QUality and Outcomes Research Unit Measure, QUORUM banding) and comparative odds of hospital mortality difference from mean performance by trust compared for 2010/2011, 2008/2009 and 2009/2010, accounting for patient-level case-mix. RESULTS The model was highly predictive of mortality (C statistic=0.93), and well calibrated by risk stratum. There was substantial overdispersion. No trusts were more than 3 SDs above the mean, and only one trust was more than 2 SDs above the mean for 2010/2011. CONCLUSIONS QUORUM is highly predictive of patient mortality in hospital or up to 30 days after admission. However, like the Summary Hospital Mortality Indicator (SHMI), QUORUM is subjected to considerable remaining legitimate but unexplained variation. It is unlikely that measures like QUORUM and SHMI will be useful beyond identifying a very small number of trusts as potential outliers.
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Abstract
UNLABELLED Serum sclerostin levels are associated with cortical porosity, suggesting that changes in sclerostin production during growth may play a role in defining cortical structure. INTRODUCTION Sclerostin, produced by osteocytes, is a potent inhibitor of Wnt signaling and bone formation. While sclerostin levels increase with age in adults and are higher in men compared to women, there is currently no information on changes in circulating sclerostin levels during growth in humans. METHODS We measured serum sclerostin levels in 6- to 21-year-old girls (n = 62) and boys (n = 56) and related these to trabecular and cortical bone microarchitectural parameters using high-resolution peripheral quantitative computed tomography and to markers of bone turnover. RESULTS Serum sclerostin levels were higher in boys as compared to girls and declined in both sexes following the onset of puberty. There was no consistent relationship between sclerostin levels and trabecular bone parameters in either sex. However, serum sclerostin levels were inversely associated with cortical volumetric bone mineral density and cortical thickness in girls and positively associated with the cortical porosity index in both girls and boys. Bone turnover markers were positively correlated with serum sclerostin levels in both sexes. CONCLUSION The gender difference in serum sclerostin levels appears to be established during puberty, and sclerostin levels tend to decline in late puberty in both girls and boys. Serum sclerostin levels are associated with cortical porosity, suggesting that changes in sclerostin production during growth may play a role in defining cortical structure.
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Abstract
OBJECTIVE To assess whether weekend admissions to hospital and/or already being an inpatient on weekend days were associated with any additional mortality risk. DESIGN Retrospective observational survivorship study. We analysed all admissions to the English National Health Service (NHS) during the financial year 2009/10, following up all patients for 30 days after admission and accounting for risk of death associated with diagnosis, co-morbidities, admission history, age, sex, ethnicity, deprivation, seasonality, day of admission and hospital trust, including day of death as a time dependent covariate. The principal analysis was based on time to in-hospital death. PARTICIPANTS National Health Service Hospitals in England. MAIN OUTCOME MEASURES 30 day mortality (in or out of hospital). RESULTS There were 14,217,640 admissions included in the principal analysis, with 187,337 in-hospital deaths reported within 30 days of admission. Admission on weekend days was associated with a considerable increase in risk of subsequent death compared with admission on weekdays, hazard ratio for Sunday versus Wednesday 1.16 (95% CI 1.14 to 1.18; P < .0001), and for Saturday versus Wednesday 1.11 (95% CI 1.09 to 1.13; P < .0001). Hospital stays on weekend days were associated with a lower risk of death than midweek days, hazard ratio for being in hospital on Sunday versus Wednesday 0.92 (95% CI 0.91 to 0.94; P < .0001), and for Saturday versus Wednesday 0.95 (95% CI 0.93 to 0.96; P < .0001). Similar findings were observed on a smaller US data set. CONCLUSIONS Admission at the weekend is associated with increased risk of subsequent death within 30 days of admission. The likelihood of death actually occurring is less on a weekend day than on a mid-week day.
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Abstract
UNLABELLED Bone strength at the ultradistal radius, quantified by micro-finite element modeling, can be predicted by variables obtained from high-resolution peripheral quantitative computed tomography scans. The specific formula for this bone strength surrogate (-555.2 + 8.1 × [trabecular vBMD] + 19.6 × [cortical area] + 4.2 × [total cross-sectional area]) should be validated and tested in fracture risk assessment. INTRODUCTION The purpose of this study was to identify key determinants of ultradistal radius (UDR) strength and evaluate their relationships with age, sex steroid levels, and measures of habitual skeletal loading. METHODS UDR failure load (~strength) was assessed by micro-finite element (μFE) modeling in 105 postmenopausal controls from an earlier forearm fracture case-control study. Predictors of bone strength obtained by high-resolution peripheral quantitative computed tomography (HRpQCT) in this group were then evaluated in a population-based cohort of 214 postmenopausal women. Sex steroids were measured by mass spectrometry. RESULTS A surrogate variable (-555.2 + 8.1 × [trabecular vBMD] + 19.6 × [cortical area] + 4.2 × [total cross-sectional area]) predicted UDR strength modeled by μFE (R(2) = 0.81), and all parameters except total cross-sectional area declined with age. Evaluated cross-sectionally, the 21% fall in predicted bone strength between ages 40-49 years and 80+ years more resembled the change in trabecular volumetric bone mineral density (vBMD) (-15%) than that in cortical area (-41%). In multivariable analyses, measures of body composition and physical activity were stronger predictors of UDR trabecular vBMD, cortical area, total cross-sectional area, and predicted bone strength than were sex steroid levels, but bio-available estradiol and testosterone were correlated with body mass. CONCLUSIONS Bone strength at the UDR, as quantified by μFE, can be predicted from variables obtained by HRpQCT. Predicted bone strength declines with age with changes in UDR trabecular vBMD and cortical area, related in turn to reduced skeletal loading and sex steroid levels. The predicted bone strength formula should be validated and tested in fracture risk assessment.
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Abstract
UNLABELLED The consensus views on osteoporosis in men are reported. INTRODUCTION A workshop was convened within a meeting on osteoporosis in men to identify areas of consensus amongst the panel (the authors) and the participants of the meeting. METHODS A public debate with an expert panel on preselected topics was conducted. RESULTS AND CONCLUSIONS Consensus views were reached on diagnostic criteria and several aspects on the pathophysiology and treatment of osteoporosis in men.
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Abstract
SUMMARY Compared to white women, lower areal bone mineral density (aBMD) in middle-aged Vietnamese immigrants is due to reduced trabecular volumetric bone mineral density (vBMD), which in turn is associated with greater trabecular separation along with lower estrogen levels. INTRODUCTION The epidemiology of osteoporosis in Asian populations is still poorly known, but we previously found a deficit in lumbar spine aBMD among postmenopausal Southeast Asian women, compared to white women, that persisted after correction for bone size. This issue was revisited using more sophisticated imaging techniques. METHODS Twenty Vietnamese immigrants (age, 44-79 years) were compared to 162 same-aged white women with respect to aBMD at the hip, spine and wrist, vBMD at the hip and spine by quantitative computed tomography and vBMD and bone microstructure at the ultradistal radius by high-resolution pQCT. Bone turnover and sex steroid levels were assessed in a subset (20 Vietnamese and 40 white women). RESULTS The aBMD was lower at all sites among the Vietnamese women, but femoral neck vBMD did not differ from middle-aged white women. Significant differences in lumbar spine and ultradistal radius vBMD in the Vietnamese immigrants were due to lower trabecular vBMD, which was associated with increased trabecular separation. Bone resorption was elevated and bone formation depressed among the Vietnamese immigrants, although trends were not statistically significant. Serum estradiol was positively associated with trabecular vBMD in the Vietnamese women, but their estrogen levels were dramatically lower compared to white women. CONCLUSIONS Although reported discrepancies in aBMD among Asian women are mainly an artifact of smaller bone size, we identified a specific deficit in the trabecular bone among a sample of Vietnamese immigrants that may be related to low estrogen levels and which needs further study.
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Abstract
UNLABELLED A diverse array of bone density, structure, and strength parameters were significantly associated with distal forearm fractures in postmenopausal women, but most of them were also correlated with femoral neck areal bone mineral density (aBMD), which provides an adequate measure of bone fragility at the wrist for routine clinical purposes. INTRODUCTION This study seeks to test the clinical utility of approaches for assessing forearm fracture risk. METHODS Among 100 postmenopausal women with a distal forearm fracture (cases) and 105 with no osteoporotic fracture (controls), we measured aBMD and assessed radius volumetric bone mineral density, geometry, and microstructure; ultradistal radius failure load was evaluated in microfinite element (microFE) models. RESULTS Fracture cases had inferior bone density, geometry, microstructure, and strength. The most significant determinant of fracture in five categories were bone density (femoral neck aBMD; odds ratio (OR) per standard deviation (SD), 2.0; 95% confidence interval (CI), 1.4-2.8), geometry (cortical thickness; OR, 1.5; 95% CI, 1.1-2.1), microstructure (structure model index (SMI); OR, 0.5; 95% CI, 0.4-0.7), and strength (microFE failure load; OR, 1.8; 95% CI, 1.3-2.5); the factor-of-risk (applied load in a forward fall / microFE failure load) was 15% worse in cases (OR, 1.9; 95% CI, 1.4-2.6). Areas under receiver operating characteristic curves (AUC) ranged from 0.62 to 0.68. The predictors of forearm fracture risk that entered a multivariable model were femoral neck aBMD and SMI (combined AUC, 0.71). CONCLUSIONS Detailed bone structure and strength measurements provide insight into forearm fracture pathogenesis, but femoral neck aBMD performs adequately for routine clinical risk assessment.
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Abstract
To further our understanding of genomic imprinting it will be essential to identify key control elements, and to investigate their regulation by both epigenetic modifications (such as DNA methylation) and trans-acting factors. So far, sequence elements that regulate parental allele-specific gene expression have been identified in a number of imprinted loci, either because of their differential DNA methylation or through functional studies in transgenic mice (1,2). A systematic search for allele-specific chromatin features constitutes an alternative strategy to identify elements that regulate imprinting. The validity of such an in vivo chromatin approach derives from the fact that in several known imprinting control-elements, a specialized organization of chromatin characterized by nuclease hypersensitivity is present on only one of the two parental chromosome (3). For example, the differentially methylated 5 -portion of the human SNRPN gene-a sequence element that controls imprinting in the Prader-Willi and Angelman syndromes' domain on chromosome 15q11- q13-has strong DNase-I hypersensitive sites on the unmethylated paternal chromosome (4). A differentially methylated region that regulates the imprinting of H19 and that of the neighboring insulin-like growth factor-2 gene on mouse chromosome 7 was also found to have parental chromosome-specific hypersensitive sites (5,6). The precise nature of the allelic nuclease hypersensitivity in these and other imprinted loci remains to be determined in more detail, for example, by applying complementary chromatin methodologies (7,8). However, it is commonly observed that a nuclease hypersensitive site corresponds to a small region where nucleosomes are absent or partially disrupted.
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