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Little is known about the incidence of osteoporosis testing and treatment in individuals with schizophrenia, who may be more likely to fracture. Using competing risk models, we found that schizophrenia was associated with lower incidence of testing or treatment. Implications are for understanding barriers and solutions for this disadvantaged group. PURPOSE: Evidence suggests that individuals with schizophrenia may be more likely to experience hip fractures than the general population; however, little is known about osteoporosis management in this disadvantaged subpopulation. Our study objective was to compare bone mineral density (BMD) testing and pharmacologic treatment in hip fracture patients with versus without schizophrenia. METHODS: This was a retrospective population-based cohort study leveraging health administrative databases, and individuals aged 66-105 years with hip fracture between fiscal years 2009 and 2018 in Ontario, Canada. Schizophrenia was ascertained using a validated algorithm. The outcome was a composite measure of (1) pharmacologic prescription for osteoporosis; or (2) a BMD test. Inferential analyses were conducted using Fine-Gray subdistribution hazard regression, with mortality as the competing event. RESULTS: A total of 52,722 individuals aged 66 to 105 years who sustained an index hip fracture in Ontario during the study period were identified, of whom 1890 (3.6%) had schizophrenia. Hip fracture patients with vs without schizophrenia were more likely to be long-term care residents (44.3% vs. 18.1%; standardized difference, 0.59), frail (62.5% vs. 36.5%; standardized difference, 0.54) and without a primary care provider (9.2% vs. 4.8%; standardized difference, 0.18). In Fine-Gray models, schizophrenia was associated with a lower incidence of testing or treatment (0.795 (0.721, 0.877)). CONCLUSIONS: In this population-based retrospective cohort study, a schizophrenia diagnosis among hip fracture patients was associated with a lower incidence of testing or treatment, after accounting for mortality, and several enabling and predisposing factors. Further research is required to investigate barriers to osteoporosis management in this disadvantaged population.
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Conservadores da Densidade Óssea , Densidade Óssea , Fraturas do Quadril , Osteoporose , Fraturas por Osteoporose , Esquizofrenia , Humanos , Fraturas do Quadril/epidemiologia , Fraturas do Quadril/fisiopatologia , Fraturas do Quadril/etiologia , Idoso , Ontário/epidemiologia , Estudos Retrospectivos , Feminino , Masculino , Idoso de 80 Anos ou mais , Fraturas por Osteoporose/epidemiologia , Fraturas por Osteoporose/fisiopatologia , Fraturas por Osteoporose/etiologia , Osteoporose/tratamento farmacológico , Osteoporose/epidemiologia , Osteoporose/fisiopatologia , Osteoporose/complicações , Densidade Óssea/fisiologia , Esquizofrenia/complicações , Esquizofrenia/epidemiologia , Esquizofrenia/fisiopatologia , Esquizofrenia/tratamento farmacológico , Conservadores da Densidade Óssea/uso terapêutico , Incidência , Absorciometria de Fóton/métodos , Bases de Dados FactuaisRESUMO
Awareness of the prevalence of osteoporosis and fractures across jurisdictions can guide the development of local preventive programs and healthcare policies. We observed geographical variations in total hip bone mineral density and in the prevalence of major osteoporotic fractures across Canadian provinces, which persisted after adjusting for important covariates. PURPOSE: We aimed to describe sex-specific total hip bone mineral density (aBMD) and prevalent major osteoporotic fractures (MOF) variation between Canadian provinces. METHODS: We used baseline data from 21,227 Canadians (10,716 women, 10,511 men) aged 50-85 years in the Canadian Longitudinal Study on Aging (CLSA; baseline: 2012-2015). Linear and logistic regression models were used to examine associations between province of residence and total hip aBMD and self-reported MOF, stratified by sex. CLSA sampling weights were used to generate the prevalence and regression estimates. RESULTS: The mean (SD) age of participants was 63.9 (9.1) years. The mean body mass index (kg/m2) was lowest in British Columbia (27.4 [5.0]) and highest in Newfoundland and Labrador (28.8 [5.3]). Women and men from British Columbia had the lowest mean total hip aBMD and the lowest prevalence of MOF. Alberta had the highest proportion of participants reporting recent falls (12.0%), and Manitoba (8.4%) the fewest (p-value=0.002). Linear regression analyses demonstrated significant differences in total hip aBMD: women and men from British Columbia and Alberta, and women from Manitoba and Nova Scotia had lower adjusted total hip aBMD than Ontario (p-values<0.02). Adjusted odds ratios (95% confidence intervals, CI) for prevalent MOF were significantly lower in women from British Columbia (0.47 [95% CI: 0.32; 0.69]) and Quebec (0.68 [95% CI: 0.48; 0.97]) and in men from British Columbia (0.40 [95% CI:0.22; 0.71]) compared to Ontario (p-values<0.03). Results were similar when adjusting for physical performance measures and when restricting the analyses to participants who reported White race/ethnicity. CONCLUSION: Geographical variations in total hip aBMD and in the prevalence of MOF between provinces persisted after adjusting for important covariates which suggests an association with unmeasured individual and environmental factors.
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Fraturas do Quadril , População Norte-Americana , Fraturas por Osteoporose , Feminino , Humanos , Masculino , Envelhecimento , Densidade Óssea , Fraturas do Quadril/epidemiologia , Estudos Longitudinais , Fraturas por Osteoporose/epidemiologia , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , CanadáRESUMO
BACKGROUND: Total knee arthroplasty (TKA) is a cost-effective procedure, but it is also associated with substantial postoperative pain. The present study aimed to compare pain relief and functional recovery after TKA among groups that received intravenous corticosteroids, periarticular corticosteroids, or a combination of both. METHODS: This randomized, double-blinded clinical trial in a local institution in Hong Kong recruited 178 patients who underwent primary unilateral TKA. Six of these patients were excluded because of changes in surgical technique; 4, because of their hepatitis B status; 2, because of a history of peptic ulcer; and 2, because they declined to participate in the study. Patients were randomized 1:1:1:1 to receive placebo (P), intravenous corticosteroids (IVS), periarticular corticosteroids (PAS), or a combination of intravenous and periarticular corticosteroids (IVSPAS). RESULTS: The pain scores at rest were significantly lower in the IVSPAS group than in the P group over the first 48 hours (p = 0.034) and 72 hours (p = 0.043) postoperatively. The pain scores during movement were also significantly lower in the IVS and IVSPAS groups than in the P group over the first 24, 48, and 72 hours (p ≤ 0.023 for all). The flexion range of the operatively treated knee was significantly better in the IVSPAS group than in the P group on postoperative day 3 (p = 0.027). Quadriceps power was also greater in the IVSPAS group than in the P group on postoperative days 2 (p = 0.005) and 3 (p = 0.007). Patients in the IVSPAS group were able to walk significantly further than patients in the P group in the first 3 postoperative days (p ≤ 0.003). Patients in the IVSPAS group also had a higher score on the Elderly Mobility Scale than those in the P group (p = 0.036). CONCLUSIONS: IVS and IVSPAS yielded similar pain relief, but IVSPAS yielded a larger number of rehabilitation parameters that were significantly better than those in the P group. This study provides new insights into pain management and postoperative rehabilitation following TKA. LEVEL OF EVIDENCE: Therapeutic Level I . See Instructions for Authors for a complete description of levels of evidence.
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Artroplastia do Joelho , Manejo da Dor , Humanos , Idoso , Manejo da Dor/métodos , Artroplastia do Joelho/efeitos adversos , Resultado do Tratamento , Dor Pós-Operatória/tratamento farmacológico , Dor Pós-Operatória/etiologia , Corticosteroides , Anestésicos Locais , Método Duplo-CegoRESUMO
HostSeq was launched in April 2020 as a national initiative to integrate whole genome sequencing data from 10,000 Canadians infected with SARS-CoV-2 with clinical information related to their disease experience. The mandate of HostSeq is to support the Canadian and international research communities in their efforts to understand the risk factors for disease and associated health outcomes and support the development of interventions such as vaccines and therapeutics. HostSeq is a collaboration among 13 independent epidemiological studies of SARS-CoV-2 across five provinces in Canada. Aggregated data collected by HostSeq are made available to the public through two data portals: a phenotype portal showing summaries of major variables and their distributions, and a variant search portal enabling queries in a genomic region. Individual-level data is available to the global research community for health research through a Data Access Agreement and Data Access Compliance Office approval. Here we provide an overview of the collective project design along with summary level information for HostSeq. We highlight several statistical considerations for researchers using the HostSeq platform regarding data aggregation, sampling mechanism, covariate adjustment, and X chromosome analysis. In addition to serving as a rich data source, the diversity of study designs, sample sizes, and research objectives among the participating studies provides unique opportunities for the research community.
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COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , COVID-19/epidemiologia , Canadá/epidemiologia , Genômica , Sequenciamento Completo do GenomaRESUMO
Gender affirming hormone therapy (GAHT) is used by many transgender people to reduce gender incongruence and improve psychological functioning. As GAHT shares many similarities with menopausal hormone therapy, clinicians supporting people through menopause are ideally placed to manage GAHT. This narrative review provides an overview of transgender health and discusses long-term effects of GAHT to consider when managing transgender individuals across the lifespan. Menopause is less relevant for transgender individuals who take GAHT (often given lifelong) to achieve sex steroid concentrations generally in the range of the affirmed gender. For people using feminizing hormone therapy, there is an elevated risk of venous thromboembolism, myocardial infarction, stroke and osteoporosis relative to cisgender individuals. For trans people using masculinizing hormone therapy, there is an increased risk of polycythemia, probable higher risk of myocardial infarction and pelvic pain which is poorly understood. Proactive mitigation of cardiovascular risk factors is important for all transgender people and optimization of bone health is important for those using feminizing hormones. With a lack of research to guide GAHT in older age, a shared decision-making approach is recommended for the provision of GAHT to achieve individual goals whilst minimizing potential adverse effects.
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Pessoas Transgênero , Transexualidade , Feminino , Humanos , Pessoas Transgênero/psicologia , Transexualidade/terapia , Hormônios , Menopausa , EnvelhecimentoRESUMO
BACKGROUND: Open-door laminoplasty (ODL) and French-door laminoplasty (FDL) are the main laminoplasty techniques used to treat cervical ossification of the posterior longitudinal ligament (C-OPLL). However, few studies have compared the outcomes of ODL and modified FDL (mFDL) for C-OPLL. We explored the differences in outcomes between ODL and mFDL for C-OPLL and analyzed the technical efficacy of each procedure in patients with K-line (+) or (-) C-OPLL. METHODS: From January 2010 to December 2015, 202 patients with K-line (+) or (-) C-OPLL were retrospectively recruited from 4 institutions. Clinical outcomes were evaluated using the Japanese Orthopaedic Association (JOA) score, JOA score recovery rate, operative time, blood loss, and complications. Univariate analysis and binary logistic regression models were adjusted for confounding factors. RESULTS: Two hundred patients (mFDL, n = 69; ODL, n = 131) with a median follow-up of 42 months (range 36-54 months) were included. The postoperative JOA score significantly improved in both groups (P < 0.05). After adjusting for confounding factors, there was a statistically significant difference in blood loss (≥ 300 mL) between the two groups (P = 0.005), but there was no significant difference in the postoperative JOA score (≥ 14) (P = 0.062), JOA score recovery rate (≥ 0.82) (P = 0.187), or operative time (≥ 90 min) (P = 0.925). C5 palsy tended to occur more often in the mFDL group, although the difference was not significant (P > 0.05). The stratified analysis of the K-line status showed more blood loss in K-line (+) patients who underwent mFDL, but there was no significant difference in the postoperative JOA score, JOA score recovery rate, or operative time between the ODL and mFDL groups. Additionally, there was no significant difference in blood loss, postoperative JOA score, JOA score recovery rate, or operative time among all patients with K-line (+) or (-) C-OPLL in both groups. CONCLUSIONS: Both ODL and mFDL are effective for patients with C-OPLL. However, more blood loss tends to occur during mFDL. This study showed no significant difference in the operative time or incidence of complications between the two techniques. The efficacy of ODL and mFDL was not affected by the K-line status (+ or -) in patients with C-OPLL.
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Laminoplastia , Ossificação do Ligamento Longitudinal Posterior , Humanos , Laminoplastia/métodos , Ligamentos Longitudinais/cirurgia , Ossificação do Ligamento Longitudinal Posterior/diagnóstico por imagem , Ossificação do Ligamento Longitudinal Posterior/cirurgia , Ossificação do Ligamento Longitudinal Posterior/complicações , Estudos Retrospectivos , Osteogênese , Vértebras Cervicais/diagnóstico por imagem , Vértebras Cervicais/cirurgia , Resultado do TratamentoRESUMO
Stenotrophomonas maltophilia is a widely distributed, Gram-negative bacillus that is increasingly identified as a multidrug-resistant opportunistic pathogen of concern. Here, we report the draft genome sequences of nine strains that were isolated from a freshwater catchment area in Hong Kong, corresponding to four different monophyletic lineages within the species.
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BACKGROUND: Physical activity guidelines for adults with disability, chronic conditions, and pregnancy (i.e., specific populations) have been developed to provide guidance for engaging in physical activity. However, specific populations remain considerably less physically active compared to the general population, presenting a knowledge-practice gap. PURPOSE: The purpose of this systematic scoping review was to identify and evaluate strategies for disseminating and implementing physical activity guidelines among specific populations and/or stakeholders (e.g., healthcare professionals) in Canada. METHODS: Five search approaches (peer-reviewed literature databases, grey literature database, custom Google search engines, targeted web-based searches, and content expert consultation) identified records documenting and/or evaluating strategies that had been used to disseminate or implement guidelines from a predetermined list. Systematic and scoping review protocols were followed. Risk of bias assessments were conducted for all studies that evaluated strategies. RESULTS: Eighty-one records reported dissemination strategies (n = 42), implementation strategies (n = 28), or both (n = 11). Twenty-two studies reporting on 29 evaluated strategies were deemed "serious" or "high" risk of bias. Common guideline dissemination and implementation strategies are deliberated and recommendations for future practice are made. CONCLUSIONS: Findings may inform future dissemination and implementation efforts for physical activity guidelines in Canada or similar countries.
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Pessoas com Deficiência , Exercício Físico , Adulto , Canadá , Doença Crônica , Feminino , Humanos , Conhecimento , GravidezRESUMO
Healthcare administrative (claims) data are commonly utilized to estimate drug effects. We identified considerable heterogeneity in fracture outcome definitions in a scoping review of 57 studies that estimated osteoporosis drug effects on fracture risk. Better understanding of the impact of different fracture definitions on study results is needed. PURPOSE: Healthcare administrative (claims) data are frequently used to estimate the real-world effects of drugs. Fracture incidence is a common outcome of osteoporosis drug studies. We aimed to describe how fractures are defined in studies that use claims data. METHODS: We searched MEDLINE (Ovid), Embase (Ovid), CINAHL (EBSCO), and gray literature for studies published in English between 2000 and 2020 that estimated fracture effectiveness (hip, humerus, radius/ulna, vertebra) or safety (atypical fracture of the femur, AFF) of osteoporosis drugs using claims data in Canada and the USA. Literature searches, screening and data abstraction were completed independently by two reviewers. RESULTS: We identified 57 eligible studies (52 effectiveness, 3 safety, 2 both). Hip fracture was the most common fracture site studied (93%), followed by humerus (66%), radius/ulna (59%), vertebra (61%), and AFF (9%). Half (n = 29) of the studies did not indicate specific data sources, codes, or cite a validation paper. Of the papers with sufficient detail, heterogeneity in fracture definitions was common. The most common definition within each fracture site was used by less than half of the studies that examined effectiveness (12 definitions in 29 hip fracture papers, 8 definitions in 17 humerus papers, 8 definitions in 13 radius/ulna papers, 9 definitions in 15 vertebra papers), and 3 definitions among 4 AFF papers. CONCLUSION: There is ambiguity and heterogeneity in fracture outcome definitions in studies that leverage claims data. Better transparency in outcome reporting is needed. Future exploration of how fracture definitions impact study results is warranted.
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Fraturas do Quadril , Osteoporose , Fraturas por Osteoporose , Atenção à Saúde , Fêmur , Fraturas do Quadril/epidemiologia , Fraturas do Quadril/etiologia , Fraturas do Quadril/prevenção & controle , Humanos , Incidência , Osteoporose/tratamento farmacológico , Osteoporose/epidemiologia , Fraturas por Osteoporose/epidemiologia , Fraturas por Osteoporose/prevenção & controleRESUMO
Breast cancer (BC) is the most common cancer among women in Hong Kong. The Food and Health Bureau commissioned The University of Hong Kong (HKU) to conduct the Hong Kong Breast Cancer Study (HKBCS) with the aim of identifying relevant risk factors for BC in Hong Kong and developing a locally validated BC risk assessment tool for Hong Kong Chinese women. After consideration of the most recent international and local scientific evidence including findings of the HKBCS, the Cancer Expert Working Group on Cancer Prevention and Screening (CEWG) has reviewed and updated its BC screening recommendations. Existing recommendations were preserved for women at high risk and slightly changed for women at moderate risk. The following major updates have been made concerning recommendations for other women in the general population: Women aged 44 to 69 with certain combinations of personalised risk factors (including presence of history of BC among first-degree relative, a prior diagnosis of benign breast disease, nulliparity and late age of first live birth, early age of menarche, high body mass index and physical inactivity) putting them at increased risk of BC are recommended to consider mammography screening every 2 years. They should discuss with their doctors on the potential benefits and harms before undergoing mammography screening. A risk assessment tool for local women (eg, one developed by HKU) is recommended to be used for estimating the risk of developing BC with regard to the personalised risk factors described above.
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Neoplasias da Mama , Detecção Precoce de Câncer , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/prevenção & controle , Feminino , Hong Kong/epidemiologia , Humanos , Masculino , Mamografia , Programas de Rastreamento , Medição de RiscoRESUMO
BACKGROUND: The Canadian 24-Hour Movement Guidelines for Children and Youth ("Guidelines") not only pioneered the notion of an integrated movement continuum from sleep to vigorous-intensity physical activity but also introduced a new branded Guideline visual identity. OBJECTIVES: This study evaluated youths' (N = 46) attention to and thoughts about the Guidelines and the brand. DESIGN: A cross-sectional between-participants randomized intervention design was used. SAMPLE: Canadian youth between 10 and 17 years of age comprised the study sample. INTERVENTIONS: Participants were randomly assigned to view either branded Guidelines (n = 26) or unbranded Guidelines (n = 20). Youths' eye-movements (e.g., dwell time, fixation count) were recorded during Guideline viewing. Participants completed a follow-up survey assessing brand perceptions and Guideline cognitions. RESULTS: The branded Guidelines neither drew greater overall attention nor led to more positive brand perceptions or Guideline cognitions compared to the unbranded Guidelines. CONCLUSIONS: Exploratory analyses provide valuable, yet preliminary insight into how branding and Guideline content may shape how Guidelines are perceived and acted upon. These findings inform an agenda for future health education resources.
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Exercício Físico , Comportamento Sedentário , Adolescente , Canadá , Criança , Estudos Transversais , Tecnologia de Rastreamento Ocular , Humanos , SonoRESUMO
Many Canadian adults are failing to meet national recommendations for physical activity, sedentary behavior, and sleep (i.e., movement behaviors). Existing messaging strategies focus on thresholds, which may be unrealistic to the target audience. This article explores the utility of a novel messaging approach - generic messages - as a gateway to enhance adults' confidence to meet the Canadian 24-Hour Movement Guidelines for Adults ('Guidelines'). In an online study, adult Guideline end-users (N = 249) completed pre-, post- and two-week surveys following exposure to generic or threshold Guideline promotional materials. Hierarchal linear regressions predicting adults' confidence to meet the Guidelines revealed an activity status by experimental condition interaction. Post hoc analyses indicated low active adults exposed to generic messages had greater confidence to meet the Guidelines compared to low active adults exposed to threshold messages. Message processing was greater among adults exposed to the generic than threshold materials. This research highlights the importance of presenting achievable behavioral goals through generic messages. Specifically, this study demonstrated that generic messaging enhances self-efficacy beliefs among low active Canadian adults. Organizations promoting behavior change among adults with low levels of behavioral engagement should consider the use of generic motivational messages within a segmented health communication campaign.
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Promoção da Saúde , Comportamento Sedentário , Adulto , Canadá , Exercício Físico , Humanos , MotivaçãoRESUMO
CLINICALTRIALS.GOV ID: NCT03631485.
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Neoplasias , Resiliência Psicológica , Criança , Humanos , Pais , Qualidade de VidaRESUMO
INTRODUCTION: Total knee arthroplasty (TKA) is an efficacious operation that improves pain and function in patients with knee arthritis. Because of the population ageing trend in Hong Kong, there is a need to determine the safety profile of TKA in older patients. This study examined the age of patients who underwent TKA in the past 10 years in Hong Kong; the aim was to investigate the mortality safety profile and clinical outcomes of TKA in patients aged ≥80 years. METHODS: This study included all patients who underwent primary TKA in the Hospital Authority (HA) from 2010 to 2019. Incidences of 30-day, 90-day, and 1-year mortality were established. Clinical outcomes of patients aged ≥80 years in one cluster of HA hospitals were assessed. RESULTS: Between 2010 and 2019, 25 040 TKA procedures were conducted in all HA hospitals; 2491 were conducted in patients aged ≥80 years. The median age at operation was higher during 2015-2019 than during 2010-2014 (70 vs 69 years; P<0.001); furthermore, an increase was observed in the proportion of patients aged ≥80 years at the time of operation. Incidences of 30-day, 90-day, and 1-year mortality were 0.156%, 0.35%, and 1.09%, respectively. CONCLUSIONS: In this first study to examine the safety profile of TKA in older patients in Hong Kong, the mean age at the time of TKA and proportion of patients aged ≥80 years have steadily risen in the past decade. Even in older patients, TKA is a reasonably safe procedure.
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Artroplastia do Joelho , Osteoartrite do Joelho , Idoso , Idoso de 80 Anos ou mais , Hong Kong/epidemiologia , Hospitais , Humanos , Incidência , Osteoartrite do Joelho/cirurgiaRESUMO
Latent class analysis (LCA) has allowed epidemiologists to overcome the practical constraints faced by traditional diagnostic test evaluation methods, which require both a gold standard diagnostic test and ample numbers of appropriate reference samples. Over the past four decades, LCA methods have expanded to allow epidemiologists to evaluate diagnostic tests and estimate true prevalence using imperfect tests over a variety of complex data structures and scenarios, including during the emergence of novel infectious diseases. The objective of this review is to provide an overview of recent developments in LCA methods, as well as a practical guide to applying Bayesian LCA (BLCA) to the evaluation of diagnostic tests. Before conducting a BLCA, the suitability of BLCA for the pathogen of interest, the availability of appropriate samples, the number of diagnostic tests, and the structure of the data should be carefully considered. While formulating the model, the model's structure and specification of informative priors will affect the likelihood that useful inferences can be drawn. With the growing need for advanced analytical methods to evaluate diagnostic tests for newly emerging diseases, LCA is a promising field of research for both the veterinary and medical disciplines.
L'analyse à classes latentes a permis aux épidémiologistes de surmonter les problèmes concrets posés par les méthodes traditionnelles d'évaluation des essais de diagnostic, qui nécessitent à la fois un test de référence absolue (étalon ou gold standard) et un grand nombre d'échantillons de référence aux caractéristiques appropriées. Au cours des quatre dernières décennies, les méthodes d'analyse à classes latentes ont acquis de l'ampleur et permettent aux épidémiologistes d'évaluer les essais diagnostiques et d'estimer les taux de prévalence réelle tout en recourant à des tests supposés imparfaits, grâce à l'utilisation de données et de scénarios divers et complexes, y compris dans les situations d'émergence de nouvelles maladies infectieuses. Les auteurs font un tour d'horizon des dernières évolutions dans ce domaine et donnent des orientations pratiques concernant la manière d'utiliser l'analyse bayésienne à classes latentes pour évaluer les performances d'un test de diagnostic. Avant de conduire une telle analyse, il convient de déterminer avec soin si elle est adaptée à l'agent pathogène considéré et si les échantillons disponibles sont appropriés et en nombre suffisant ; il convient également de prendre en compte le nombre de tests de diagnostic à évaluer et la structure des données utilisées. Lors de la conception du modèle, sa structure et la définition préalable des données informatives vont affecter la probabilité que le modèle génère des inférences utiles. Face à la nécessité croissante de disposer de méthodes analytiques sophistiquées pour évaluer les tests de diagnostic utilisés pour les maladies émergentes nouvelles, les analyses à classes latentes offrent des perspectives prometteuses pour la recherche, aussi bien dans le domaine de la santé vétérinaire que de la médecine humaine.
El análisis de clases latentes ha servido a los epidemiólogos para superar las limitaciones prácticas que imponen los métodos tradicionales de evaluación de pruebas de diagnóstico, que requieren a la vez una prueba de diagnóstico que sirva de patrón de referencia perfecto y un gran número de muestras de referencia adecuadas. En los últimos cuatro decenios, los métodos de análisis de clases latentes se han ido ampliando hasta permitir a los epidemiólogos evaluar pruebas de diagnóstico y calcular la prevalencia real empleando pruebas imperfectas ante muy diversas estructuras de datos y situaciones complejas, incluida la aparición de nuevas enfermedades infecciosas. Los autores, tras presentar a grandes líneas los últimos adelantos en cuanto a métodos de análisis de clases latentes, ofrecen indicaciones prácticas para aplicar el análisis bayesiano de clases latentes a la evaluación de pruebas de diagnóstico. Antes de proceder a un análisis bayesiano de este tipo conviene estudiar con detenimiento la idoneidad del método para el patógeno en cuestión, la disponibilidad de muestras apropiadas, el número de pruebas de diagnóstico y la estructura de los datos. A la hora de formular el modelo, la estructura del propio modelo y la especificación de los elementos informativos previos influirán en la probabilidad de poder extraer conclusiones provechosas. Ante la creciente necesidad de disponer de métodos analíticos avanzados con los que evaluar pruebas de diagnóstico de nuevas enfermedades emergentes, el análisis de clases latentes abre un promisorio campo de investigación para las disciplinas veterinarias y médicas.
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Doenças Transmissíveis , Testes Diagnósticos de Rotina , Animais , Teorema de Bayes , Doenças Transmissíveis/veterinária , Testes Diagnósticos de Rotina/veterinária , Análise de Classes Latentes , Padrões de Referência , Sensibilidade e EspecificidadeRESUMO
BACKGROUND: Prognostic stratification of breast cancers remains a challenge to improve clinical decision making. We employ machine learning on breast cancer transcriptomics from multiple studies to link the expression of specific genes to histological grade and classify tumours into a more or less aggressive prognostic type. MATERIALS AND METHODS: Microarray data of 5031 untreated breast tumours spanning 33 published datasets and corresponding clinical data were integrated. A machine learning model based on gradient boosted trees was trained on histological grade-1 and grade-3 samples. The resulting predictive model (Cancer Grade Model, CGM) was applied on samples of grade-2 and unknown-grade (3029) for prognostic risk classification. RESULTS: A 70-gene signature for assessing clinical risk was identified and was shown to be 90% accurate when tested on known histological-grade samples. The predictive framework was validated through survival analysis and showed robust prognostic performance. CGM was cross-referenced with existing genomic tests and demonstrated the competitive predictive power of tumour risk. CONCLUSIONS: CGM is able to classify tumours into better-defined prognostic categories without employing information on tumour size, stage, or subgroups. The model offers means to improve prognosis and support the clinical decision and precision treatments, thereby potentially contributing to preventing underdiagnosis of high-risk tumours and minimising over-treatment of low-risk disease.
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Biomarcadores Tumorais/genética , Neoplasias da Mama/patologia , Perfilação da Expressão Gênica/métodos , Neoplasias da Mama/genética , Bases de Dados Genéticas , Sistemas de Apoio a Decisões Clínicas , Feminino , Humanos , Aprendizado de Máquina , Gradação de Tumores , Análise de Sequência com Séries de Oligonucleotídeos , Prognóstico , Análise de SobrevidaRESUMO
High-resolution peripheral computed tomography (HR-pQCT) was developed to image bone microarchitecture in vivo at peripheral skeletal sites. Since the introduction of HR-pQCT in 2005, clinical research to gain insight into pathophysiology of skeletal fragility and to improve prediction of fractures has grown. Meanwhile, the second-generation HR-pQCT device has been introduced, allowing novel applications such as hand joint imaging, assessment of subchondral bone and cartilage thickness in the knee, and distal radius fracture healing. This article provides an overview of the current clinical applications and guidance on interpretation of results, as well as future directions. Specifically, we provide an overview of (1) the differences and reference data for HR-pQCT variables by age, sex, and race/ethnicity; (2) fracture risk prediction using HR-pQCT; (3) the ability to monitor response of anti-osteoporosis therapy with HR-pQCT; (4) the use of HR-pQCT in patients with metabolic bone disorders and diseases leading to secondary osteoporosis; and (5) novel applications of HR-pQCT imaging. Finally, we summarize the status of the application of HR-pQCT in clinical practice and discuss future directions. From the clinical perspective, there are both challenges and opportunities for more widespread use of HR-pQCT. Assessment of bone microarchitecture by HR-pQCT improves fracture prediction in mostly normal or osteopenic elderly subjects beyond DXA of the hip, but the added value is marginal. The prospects of HR-pQCT in clinical practice need further study with respect to medication effects, metabolic bone disorders, rare bone diseases, and other applications such as hand joint imaging and fracture healing. The mostly unexplored potential may be the differentiation of patients with only moderately low BMD but severe microstructural deterioration, which would have important implications for the decision on therapeutical interventions.