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1.
Pediatr Infect Dis J ; 42(8): e274-e277, 2023 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-37171965

RESUMEN

BACKGROUND: Young children with acute otitis media (AOM) frequently exhibit nasopharyngeal colonization with either Streptococcus pneumoniae, Haemophilus influenzae or both pathogens. We aimed to determine if antibiotics could be spared or shortened in those without nasopharyngeal colonization with either pathogen. METHODS: In 2 separate randomized clinical trials in children aged 6-23 months with stringently-diagnosed AOM, we performed bacterial cultures on nasopharyngeal specimens collected at the time of diagnosis. In the first trial, we compared the efficacy of amoxicillin/clavulanate (amox/clav) administered for 10 days vs. that of placebo, and in the second trial, we compared the efficacy of amox/clav administered for 10 days vs. 5 days. In each trial, we classified children as being colonized with both S. pneumoniae and H. influenzae, S. pneumoniae alone, H. influenzae alone, or neither pathogen, and as experiencing either clinical success or clinical failure at the end-of-therapy visit, based on previously reported a priori criteria. RESULTS: We evaluated 796 children. Among children randomized to amox/clav, those colonized with either S. pneumoniae or H. influenzae or both were approximately twice as likely to experience clinical failure as children not colonized with either pathogen (odds ratio: 1.8; confidence intervals: 1.2-2.9). In contrast, among children randomized to placebo, clinical failure at the end-of-therapy visit was not associated with nasopharyngeal culture results at the time of diagnosis. CONCLUSIONS: Children colonized with either S. pneumoniae or H. influenzae or both have a greater chance of treatment failure than children colonized with neither pathogen.


Asunto(s)
Otitis Media , Niño , Humanos , Lactante , Preescolar , Otitis Media/tratamiento farmacológico , Otitis Media/microbiología , Antibacterianos/uso terapéutico , Combinación Amoxicilina-Clavulanato de Potasio/uso terapéutico , Insuficiencia del Tratamiento , Streptococcus pneumoniae , Enfermedad Aguda , Haemophilus influenzae , Nasofaringe/microbiología
2.
ACR Open Rheumatol ; 4(11): 983-990, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36128663

RESUMEN

OBJECTIVE: To assess the efficacy and tolerability of tocilizumab in a multicenter, randomized, double-blind, placebo-controlled trial in refractory adult patients with dermatomyositis (DM) and polymyositis (PM). METHODS: Thirty-six subjects with probable or definite DM/PM were enrolled in a 6-month phase 2B clinical trial and randomized 1:1 to receive tocilizumab (8 mg/kg intravenously) or placebo every 4 weeks for 24 weeks. Eligible subjects had either a DM rash, a myositis-associated autoantibody or an adjudicated PM diagnosis. Active disease was defined by at least three of six abnormal core set measures (CSMs), including a manual muscle testing (MMT)-8 score of less than 136/150. If the MMT-8 score was greater than 136, then a cutaneous score of 3 or more (10 cm visual analogue scale) was required along with three additional abnormal CSMs indicating disease activity. The primary endpoint compared the Total Improvement Score (TIS) between both arms from week 4 to 24. Secondary outcomes included time to meeting minimal TIS improvement, changes in CSMs, time to worsening, steroid-sparing effect, proportion of subjects meeting more stringent improvement criteria, and safety outcomes. RESULTS: There was no significant difference (P = 0.86) in the TIS over 24 weeks between tocilizumab and placebo arms. The secondary endpoints of time to improvement (minimal, moderate, or major), time to worsening, CSM changes, safety outcomes, and steroid-sparing effect were also not significantly different between arms. CONCLUSION: Tocilizumab was safe and well tolerated but did not meet the primary or secondary efficacy outcomes in refractory DM and PM in this 24-week phase 2B study.

3.
Pediatr Nephrol ; 35(11): 2113-2120, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32556960

RESUMEN

BACKGROUND: To evaluate the efficacy of adjuvant systemic corticosteroids in reducing kidney scarring. A previous study suggested that use of adjuvant systemic corticosteroids reduces kidney scarring in children radiologically confirmed to have extensive pyelonephritis. Efficacy of corticosteroids for children with febrile urinary tract infection (UTI) has not been studied. METHODS: Children aged 2 months to 6 years with their first febrile UTI were randomized to corticosteroids or placebo for 3 days (both arms received antimicrobial therapy); kidney scarring was assessed using 99mTc-dimercaptosuccinic acid kidney scan 5-24 months after the initial UTI. RESULTS: We randomized 546 children of which 385 had a UTI and 254 had outcome kidney scans (instead of the 320 planned). Rates of kidney scarring were 9.8% (12/123) and 16.8% (22/131) in the corticosteroid and placebo groups, respectively (p = 0.16), corresponding to an absolute risk reduction of 5.9% (95% confidence interval: - 2.2, 14.1). CONCLUSION: While children randomized to adjuvant corticosteroids tended to develop fewer kidney scars than children who were randomized to receive placebo, a statistically significant difference was not achieved. However, the study was limited by not reaching its intended sample size. CLINICAL TRIAL REGISTRATION: Clinicaltrials.gov , NCT01391793, Registered 7/12/2011 Graphical abstract.


Asunto(s)
Corticoesteroides/administración & dosificación , Glomerulonefritis/prevención & control , Infecciones Urinarias/tratamiento farmacológico , Adyuvantes Farmacéuticos/administración & dosificación , Adyuvantes Farmacéuticos/efectos adversos , Corticoesteroides/efectos adversos , Factores de Edad , Antibacterianos/uso terapéutico , Preescolar , Método Doble Ciego , Femenino , Fiebre , Glomerulonefritis/diagnóstico por imagen , Humanos , Lactante , Masculino
5.
Rheumatology (Oxford) ; 56(11): 1884-1893, 2017 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-28977549

RESUMEN

Objective: The objective was to describe the methodology used to develop new response criteria for adult DM/PM and JDM. Methods: Patient profiles from prospective natural history data and clinical trials were rated by myositis specialists to develop consensus gold-standard ratings of minimal, moderate and major improvement. Experts completed a survey regarding clinically meaningful improvement in the core set measures (CSM) and a conjoint-analysis survey (using 1000Minds software) to derive relative weights of CSM and candidate definitions. Six types of candidate definitions for response criteria were derived using survey results, logistic regression, conjoint analysis, application of conjoint-analysis weights to CSM and published definitions. Sensitivity, specificity and area under the curve were defined for candidate criteria using consensus patient profile data, and selected definitions were validated using clinical trial data. Results: Myositis specialists defined the degree of clinically meaningful improvement in CSM for minimal, moderate and major improvement. The conjoint-analysis survey established the relative weights of CSM, with muscle strength and Physician Global Activity as most important. Many candidate definitions showed excellent sensitivity, specificity and area under the curve in the consensus profiles. Trial validation showed that a number of candidate criteria differentiated between treatment groups. Top candidate criteria definitions were presented at the consensus conference. Conclusion: Consensus methodology, with definitions tested on patient profiles and validated using clinical trials, led to 18 definitions for adult PM/DM and 14 for JDM as excellent candidates for consideration in the final consensus on new response criteria for myositis.


Asunto(s)
Dermatomiositis/terapia , Área Bajo la Curva , Humanos , Modelos Logísticos , Diferencia Mínima Clínicamente Importante , Polimiositis/terapia , Resultado del Tratamiento
6.
Artículo en Inglés | MEDLINE | ID: mdl-28438923

RESUMEN

Amoxicillin-clavulanate (A/C) is currently the most effective oral antimicrobial in treating children with acute otitis media (AOM), but the standard dosage of 90 mg amoxicillin/6.4 mg clavulanate/kg of body weight/day commonly causes diarrhea. We examined whether an A/C formulation containing lower concentrations of clavulanate would result in less diarrhea while maintaining plasma levels of amoxicillin and clavulanate adequate to eradicate middle-ear pathogens and to achieve clinical success. We conducted an open-label study in children with AOM who were 6 to 23 months of age. In phase 1, we treated 40 children with a reduced-clavulanate A/C formulation providing 90 mg amoxicillin/3.2 mg clavulanate/kg/day for 10 days. In phase 2, we treated 72 children with the same formulation at a dosage of 80 mg amoxicillin/2.85 mg clavulanate/kg/day for 10 days. We compared the rates of protocol-defined diarrhea (PDD), diaper dermatitis, and AOM clinical response in these children with rates we had reported in children who received the standard A/C regimen, and we obtained plasma levels of amoxicillin and clavulanate at various time points. Outcomes in phase 1 children and in children who had received the standard regimen did not differ significantly. Rates of PDD in children receiving phase 2 and standard regimens were 17% and 26%, respectively (P = 0.10). The corresponding rates of diaper dermatitis were 21% and 33% (P = 0.04) and of AOM treatment failure were 12% and 16% (P = 0.44). Symptomatic responses did not differ significantly between regimens; both gave clavulanate levels sufficient to inhibit ß-lactamase activity. In young children with AOM, clavulanate dosages lower than those currently used may be associated with fewer side effects without reducing clinical efficacy. (This study has been registered at ClinicalTrials.gov under registration no. NCT02630992.).


Asunto(s)
Combinación Amoxicilina-Clavulanato de Potasio/uso terapéutico , Antibacterianos/uso terapéutico , Ácido Clavulánico/uso terapéutico , Otitis Media/tratamiento farmacológico , Combinación Amoxicilina-Clavulanato de Potasio/administración & dosificación , Combinación Amoxicilina-Clavulanato de Potasio/efectos adversos , Antibacterianos/administración & dosificación , Antibacterianos/efectos adversos , Ácido Clavulánico/administración & dosificación , Ácido Clavulánico/efectos adversos , Dermatitis/etiología , Diarrea/inducido químicamente , Femenino , Humanos , Lactante , Recién Nacido , Masculino
7.
Ann Rheum Dis ; 76(5): 782-791, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-28385804

RESUMEN

To develop response criteria for juvenile dermatomyositis (DM). We analysed the performance of 312 definitions that used core set measures from either the International Myositis Assessment and Clinical Studies Group (IMACS) or the Paediatric Rheumatology International Trials Organisation (PRINTO) and were derived from natural history data and a conjoint analysis survey. They were further validated using data from the PRINTO trial of prednisone alone compared to prednisone with methotrexate or cyclosporine and the Rituximab in Myositis (RIM) trial. At a consensus conference, experts considered 14 top candidate criteria based on their performance characteristics and clinical face validity, using nominal group technique. Consensus was reached for a conjoint analysis-based continuous model with a total improvement score of 0-100, using absolute per cent change in core set measures of minimal (≥30), moderate (≥45), and major (≥70) improvement. The same criteria were chosen for adult DM/polymyositis, with differing thresholds for improvement. The sensitivity and specificity were 89% and 91-98% for minimal improvement, 92-94% and 94-99% for moderate improvement, and 91-98% and 85-86% for major improvement, respectively, in juvenile DM patient cohorts using the IMACS and PRINTO core set measures. These criteria were validated in the PRINTO trial for differentiating between treatment arms for minimal and moderate improvement (p=0.009-0.057) and in the RIM trial for significantly differentiating the physician's rating for improvement (p<0.006). The response criteria for juvenile DM consisted of a conjoint analysis-based model using a continuous improvement score based on absolute per cent change in core set measures, with thresholds for minimal, moderate, and major improvement.


Asunto(s)
Dermatomiositis/terapia , Evaluación de Resultado en la Atención de Salud/normas , Índice de Severidad de la Enfermedad , Adolescente , Adulto , Niño , Preescolar , Consenso , Humanos , Ensayos Clínicos Controlados Aleatorios como Asunto , Sensibilidad y Especificidad
8.
Ann Rheum Dis ; 76(5): 792-801, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-28385805

RESUMEN

To develop response criteria for adult dermatomyositis (DM) and polymyositis (PM). Expert surveys, logistic regression, and conjoint analysis were used to develop 287 definitions using core set measures. Myositis experts rated greater improvement among multiple pairwise scenarios in conjoint analysis surveys, where different levels of improvement in 2 core set measures were presented. The PAPRIKA (Potentially All Pairwise Rankings of All Possible Alternatives) method determined the relative weights of core set measures and conjoint analysis definitions. The performance characteristics of the definitions were evaluated on patient profiles using expert consensus (gold standard) and were validated using data from a clinical trial. The nominal group technique was used to reach consensus. Consensus was reached for a conjoint analysis-based continuous model using absolute per cent change in core set measures (physician, patient, and extramuscular global activity, muscle strength, Health Assessment Questionnaire, and muscle enzyme levels). A total improvement score (range 0-100), determined by summing scores for each core set measure, was based on improvement in and relative weight of each core set measure. Thresholds for minimal, moderate, and major improvement were ≥20, ≥40, and ≥60 points in the total improvement score. The same criteria were chosen for juvenile DM, with different improvement thresholds. Sensitivity and specificity in DM/PM patient cohorts were 85% and 92%, 90% and 96%, and 92% and 98% for minimal, moderate, and major improvement, respectively. Definitions were validated in the clinical trial analysis for differentiating the physician rating of improvement (p<0.001). The response criteria for adult DM/PM consisted of the conjoint analysis model based on absolute per cent change in 6 core set measures, with thresholds for minimal, moderate, and major improvement.


Asunto(s)
Dermatomiositis/terapia , Evaluación de Resultado en la Atención de Salud/normas , Índice de Severidad de la Enfermedad , Adolescente , Adulto , Niño , Preescolar , Consenso , Humanos , Polimiositis/terapia , Ensayos Clínicos Controlados Aleatorios como Asunto , Sensibilidad y Especificidad
9.
Arthritis Rheumatol ; 69(5): 911-923, 2017 05.
Artículo en Inglés | MEDLINE | ID: mdl-28382778

RESUMEN

OBJECTIVE: To develop response criteria for juvenile dermatomyositis (DM). METHODS: We analyzed the performance of 312 definitions that used core set measures from either the International Myositis Assessment and Clinical Studies Group (IMACS) or the Paediatric Rheumatology International Trials Organisation (PRINTO) and were derived from natural history data and a conjoint analysis survey. They were further validated using data from the PRINTO trial of prednisone alone compared to prednisone with methotrexate or cyclosporine and the Rituximab in Myositis (RIM) trial. At a consensus conference, experts considered 14 top candidate criteria based on their performance characteristics and clinical face validity, using nominal group technique. RESULTS: Consensus was reached for a conjoint analysis-based continuous model with a total improvement score of 0-100, using absolute percent change in core set measures of minimal (≥30), moderate (≥45), and major (≥70) improvement. The same criteria were chosen for adult DM/polymyositis, with differing thresholds for improvement. The sensitivity and specificity were 89% and 91-98% for minimal improvement, 92-94% and 94-99% for moderate improvement, and 91-98% and 85-86% for major improvement, respectively, in juvenile DM patient cohorts using the IMACS and PRINTO core set measures. These criteria were validated in the PRINTO trial for differentiating between treatment arms for minimal and moderate improvement (P = 0.009-0.057) and in the RIM trial for significantly differentiating the physician's rating for improvement (P < 0.006). CONCLUSION: The response criteria for juvenile DM consisted of a conjoint analysis-based model using a continuous improvement score based on absolute percent change in core set measures, with thresholds for minimal, moderate, and major improvement.


Asunto(s)
Antirreumáticos/uso terapéutico , Dermatomiositis/tratamiento farmacológico , Glucocorticoides/uso terapéutico , Adolescente , Alanina Transaminasa/metabolismo , Aspartato Aminotransferasas/metabolismo , Niño , Creatina Quinasa/metabolismo , Ciclosporina/uso terapéutico , Dermatomiositis/metabolismo , Dermatomiositis/fisiopatología , Europa (Continente) , Fructosa-Bifosfato Aldolasa/metabolismo , Humanos , L-Lactato Deshidrogenasa/metabolismo , Modelos Logísticos , Metotrexato/uso terapéutico , Fuerza Muscular , Evaluación de Resultado en la Atención de Salud , Medición de Resultados Informados por el Paciente , Prednisona/uso terapéutico , Reproducibilidad de los Resultados , Reumatología , Rituximab/uso terapéutico , Sociedades Médicas , Encuestas y Cuestionarios , Resultado del Tratamiento , Estados Unidos
10.
Arthritis Rheumatol ; 69(5): 898-910, 2017 05.
Artículo en Inglés | MEDLINE | ID: mdl-28382787

RESUMEN

OBJECTIVE: To develop response criteria for adult dermatomyositis (DM) and polymyositis (PM). METHODS: Expert surveys, logistic regression, and conjoint analysis were used to develop 287 definitions using core set measures. Myositis experts rated greater improvement among multiple pairwise scenarios in conjoint analysis surveys, where different levels of improvement in 2 core set measures were presented. The PAPRIKA (Potentially All Pairwise Rankings of All Possible Alternatives) method determined the relative weights of core set measures and conjoint analysis definitions. The performance characteristics of the definitions were evaluated on patient profiles using expert consensus (gold standard) and were validated using data from a clinical trial. The nominal group technique was used to reach consensus. RESULTS: Consensus was reached for a conjoint analysis-based continuous model using absolute percent change in core set measures (physician, patient, and extramuscular global activity, muscle strength, Health Assessment Questionnaire, and muscle enzyme levels). A total improvement score (range 0-100), determined by summing scores for each core set measure, was based on improvement in and relative weight of each core set measure. Thresholds for minimal, moderate, and major improvement were ≥20, ≥40, and ≥60 points in the total improvement score. The same criteria were chosen for juvenile DM, with different improvement thresholds. Sensitivity and specificity in DM/PM patient cohorts were 85% and 92%, 90% and 96%, and 92% and 98% for minimal, moderate, and major improvement, respectively. Definitions were validated in the clinical trial analysis for differentiating the physician rating of improvement (P < 0.001). CONCLUSION: The response criteria for adult DM/PM consisted of the conjoint analysis model based on absolute percent change in 6 core set measures, with thresholds for minimal, moderate, and major improvement.


Asunto(s)
Antirreumáticos/uso terapéutico , Dermatomiositis/tratamiento farmacológico , Alanina Transaminasa/metabolismo , Aspartato Aminotransferasas/metabolismo , Creatina Quinasa/metabolismo , Dermatomiositis/metabolismo , Dermatomiositis/fisiopatología , Europa (Continente) , Fructosa-Bifosfato Aldolasa/metabolismo , Humanos , L-Lactato Deshidrogenasa/metabolismo , Modelos Logísticos , Fuerza Muscular , Evaluación de Resultado en la Atención de Salud , Medición de Resultados Informados por el Paciente , Polimiositis/tratamiento farmacológico , Polimiositis/metabolismo , Polimiositis/fisiopatología , Reumatología , Sociedades Médicas , Encuestas y Cuestionarios , Resultado del Tratamiento , Estados Unidos
11.
N Engl J Med ; 375(25): 2446-2456, 2016 12 22.
Artículo en Inglés | MEDLINE | ID: mdl-28002709

RESUMEN

BACKGROUND: Limiting the duration of antimicrobial treatment constitutes a potential strategy to reduce the risk of antimicrobial resistance among children with acute otitis media. METHODS: We assigned 520 children, 6 to 23 months of age, with acute otitis media to receive amoxicillin-clavulanate either for a standard duration of 10 days or for a reduced duration of 5 days followed by placebo for 5 days. We measured rates of clinical response (in a systematic fashion, on the basis of signs and symptomatic response), recurrence, and nasopharyngeal colonization, and we analyzed episode outcomes using a noninferiority approach. Symptom scores ranged from 0 to 14, with higher numbers indicating more severe symptoms. RESULTS: Children who were treated with amoxicillin-clavulanate for 5 days were more likely than those who were treated for 10 days to have clinical failure (77 of 229 children [34%] vs. 39 of 238 [16%]; difference, 17 percentage points [based on unrounded data]; 95% confidence interval, 9 to 25). The mean symptom scores over the period from day 6 to day 14 were 1.61 in the 5-day group and 1.34 in the 10-day group (P=0.07); the mean scores at the day-12-to-14 assessment were 1.89 versus 1.20 (P=0.001). The percentage of children whose symptom scores decreased more than 50% (indicating less severe symptoms) from baseline to the end of treatment was lower in the 5-day group than in the 10-day group (181 of 227 children [80%] vs. 211 of 233 [91%], P=0.003). We found no significant between-group differences in rates of recurrence, adverse events, or nasopharyngeal colonization with penicillin-nonsusceptible pathogens. Clinical-failure rates were greater among children who had been exposed to three or more children for 10 or more hours per week than among those with less exposure (P=0.02) and were also greater among children with infection in both ears than among those with infection in one ear (P<0.001). CONCLUSIONS: Among children 6 to 23 months of age with acute otitis media, reduced-duration antimicrobial treatment resulted in less favorable outcomes than standard-duration treatment; in addition, neither the rate of adverse events nor the rate of emergence of antimicrobial resistance was lower with the shorter regimen. (Funded by the National Institute of Allergy and Infectious Diseases and the National Center for Research Resources; ClinicalTrials.gov number, NCT01511107 .).


Asunto(s)
Combinación Amoxicilina-Clavulanato de Potasio/administración & dosificación , Antiinfecciosos/administración & dosificación , Otitis Media/tratamiento farmacológico , Enfermedad Aguda , Combinación Amoxicilina-Clavulanato de Potasio/efectos adversos , Antiinfecciosos/efectos adversos , Esquema de Medicación , Farmacorresistencia Bacteriana , Femenino , Haemophilus influenzae/aislamiento & purificación , Humanos , Lactante , Masculino , Nasofaringe/microbiología , Pronóstico , Streptococcus pneumoniae/aislamiento & purificación , Insuficiencia del Tratamiento
12.
J Pediatric Infect Dis Soc ; 4(4): 367-9, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26582877

RESUMEN

The objective of the present study was to determine whether changes in the previously developed 7-item Acute Otitis Media Severity of Symptoms scale could improve its responsiveness and its longitudinal construct validity. The items "diminished activity" and "diminished appetite" had low or borderline levels of responsiveness and longitudinal construct validity. Dropping these items seems to be potentially advantageous.


Asunto(s)
Otitis Media/diagnóstico , Índice de Severidad de la Enfermedad , Enfermedad Aguda , Combinación Amoxicilina-Clavulanato de Potasio/uso terapéutico , Humanos , Lactante , Otitis Media/tratamiento farmacológico
13.
Pediatr Infect Dis J ; 34(3): e41-3, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25259933

RESUMEN

BACKGROUND: We previously developed and validated the acute otitis media severity of symptom (AOM-SOS) scale for rating symptoms of AOM in young children. In this report, we sought to estimate the minimal important difference (MID) for change in AOM-SOS scores. METHODS: In a group of children 6-24 months of age with AOM enrolled in a recently reported placebo-controlled clinical trial of antibiotic efficacy, we compared changes in AOM-SOS scores with parental assessments of change over a 24-hour period. Mean absolute and mean relative change in scores in children reportedly exhibiting only a small degree of improvement were considered in arriving at an estimated MID. We then compared the proportions of children in the antibiotic and placebo groups, respectively, whose AOM-SOS scores changed more than the estimated MID at various time points after enrollment. RESULTS: Data were available for 277 children. Children whose parents reported only a small degree of improvement 24 hours after enrollment had a mean decrease in AOM-SOS score of 3.8, or 55%, from baseline. We found the relative decrease more telling than the absolute decrease. The proportions of children in the antibiotic and placebo groups, respectively, whose AOM-SOS scores had decreased <55% on Day 7 were 12.3 and 23.8% (P=0.02), and during Days 4-7 were 28 and 40% (P=0.046). CONCLUSIONS: We estimated the MID for change in AOM-SOS scores in young children and described use of the MID as an added metric in interpreting results from a clinical trial of antibiotic efficacy.


Asunto(s)
Otitis Media/diagnóstico , Índice de Severidad de la Enfermedad , Enfermedad Aguda , Antibacterianos/uso terapéutico , Preescolar , Femenino , Humanos , Lactante , Masculino , Otitis Media/tratamiento farmacológico , Padres , Encuestas y Cuestionarios
15.
Med Phys ; 40(5): 051706, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23635254

RESUMEN

PURPOSE: To develop an approach of estimating subject-centered free-response receiver operating characteristic (FROC) curve for providing patient-centered inferences regarding detection-localization characteristics of a diagnostic system. METHODS: The authors examine properties of the conventional, target-centered, FROC curve and demonstrate that in scenarios where the diagnostic performance correlates with the total number of targets on a subject, it may lead to inadequate inferences from the perspective of possible benefits to a patient. Following solutions to patient-centered approaches in other applications, the authors define a subject-centered FROC curve and develop its formulation as a covariate-adjusted FROC curve. The authors also conduct a numerical study illustrating the relative properties of the conventional and subject-centered approach and provide an example. RESULTS: A simple-to-implement approach for estimating the subject-centered FROC curve and its overall index can be formulated as a type of stratified FROC analysis. The authors demonstrate that when diagnostic performance is associated with the number of targets, the diagnostic system with apparently superior target-centered characteristics (conventional approach) can be actually inferior from the subject-centered perspective. The authors show that under some clinically reasonable conditions the magnitude of disagreement in results could be substantial. An example from an actual observer performance study illustrates the natural setting where the developed approach would be relevant and lead to conclusions that are contradictory to those obtained from conventional analysis. CONCLUSIONS: The authors developed a subject-centered FROC curve and its overall index provides tools for inferences that may be relevant from a perspective of potential benefits to a patient.


Asunto(s)
Diagnóstico , Curva ROC , Algoritmos , Humanos , Modelos Teóricos
16.
Stat Med ; 32(20): 3449-58, 2013 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-23508757

RESUMEN

Evaluation of diagnostic performance is a necessary component of new developments in many fields including medical diagnostics and decision making. The methodology for statistical analysis of diagnostic performance continues to develop, offering new analytical tools for conventional inferences and solutions for novel and increasingly more practically relevant questions. In this paper, we focus on the partial area under the Receiver Operating Characteristic (ROC) curve or pAUC. This summary index is considered to be more practically relevant than the area under the entire ROC curve (AUC), but because of several perceived limitations, it is not used as often. To improve interpretation, results for pAUC analysis are frequently reported using a rescaled index such as the standardized partial AUC proposed by McClish (1989). We derive two important properties of the relationship between the 'standardized' pAUC and the defined range of interest, which could facilitate a wider and more appropriate use of this important summary index. First, we mathematically prove that the 'standardized' pAUC increases with increasing range of interest for practically common ROC curves. Second, using comprehensive numerical investigations, we demonstrate that, contrary to common belief, the uncertainty about the estimated standardized pAUC can either decrease or increase with an increasing range of interest. Our results indicate that the partial AUC could frequently offer advantages in terms of statistical uncertainty of the estimation. In addition, selection of a wider range of interest will likely lead to an increased estimate even for standardized pAUC.


Asunto(s)
Pruebas Diagnósticas de Rutina/normas , Curva ROC , Área Bajo la Curva , Simulación por Computador , Humanos , Enfermedades Pulmonares Intersticiales/diagnóstico por imagen , Neoplasias Pulmonares/diagnóstico por imagen , Variaciones Dependientes del Observador , Radiografía
18.
Arthritis Rheum ; 65(2): 314-24, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23124935

RESUMEN

OBJECTIVE: To assess the safety and efficacy of rituximab in a randomized, double-blind, placebo-phase trial in adult and pediatric myositis patients. METHODS: Adults with refractory polymyositis (PM) and adults and children with refractory dermatomyositis (DM) were enrolled. Entry criteria included muscle weakness and ≥2 additional abnormal values on core set measures (CSMs) for adults. Juvenile DM patients required ≥3 abnormal CSMs, with or without muscle weakness. Patients were randomized to receive either rituximab early or rituximab late, and glucocorticoid or immunosuppressive therapy was allowed at study entry. The primary end point compared the time to achieve the International Myositis Assessment and Clinical Studies Group preliminary definition of improvement (DOI) between the 2 groups. The secondary end points were the time to achieve ≥20% improvement in muscle strength and the proportions of patients in the early and late rituximab groups achieving the DOI at week 8. RESULTS: Among 200 randomized patients (76 with PM, 76 with DM, and 48 with juvenile DM), 195 showed no difference in the time to achieving the DOI between the rituximab late (n = 102) and rituximab early (n = 93) groups (P = 0.74 by log rank test), with a median time to achieving a DOI of 20.2 weeks and 20.0 weeks, respectively. The secondary end points also did not significantly differ between the 2 treatment groups. However, 161 (83%) of the randomized patients met the DOI, and individual CSMs improved in both groups throughout the 44-week trial. CONCLUSION: Although there were no significant differences in the 2 treatment arms for the primary and secondary end points, 83% of adult and juvenile myositis patients with refractory disease met the DOI. The role of B cell-depleting therapies in myositis warrants further study, with consideration for a different trial design.


Asunto(s)
Anticuerpos Monoclonales de Origen Murino/uso terapéutico , Antirreumáticos/uso terapéutico , Dermatomiositis/tratamiento farmacológico , Polimiositis/tratamiento farmacológico , Adolescente , Adulto , Anciano , Niño , Método Doble Ciego , Femenino , Glucocorticoides/uso terapéutico , Humanos , Masculino , Persona de Mediana Edad , Debilidad Muscular/tratamiento farmacológico , Dimensión del Dolor , Placebos , Rituximab , Índice de Severidad de la Enfermedad , Resultado del Tratamiento
19.
J Urol ; 188(5): 1895-9, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22998917

RESUMEN

PURPOSE: Various screening approaches have been proposed to identify the subgroup of children with urinary tract infection who have vesicoureteral reflux. However, few studies have compared the sensitivity of screening approaches in a representative population of young children. We compared the sensitivities of the top-down ((99m)technetium dimercaptosuccinic acid renal scan to screen) and biomarker based (C-reactive protein level at presentation) approaches in identifying children with vesicoureteral reflux. MATERIALS AND METHODS: We calculated the sensitivity of the 2 screening approaches in detecting vesicoureteral reflux and subsequently high grade (III or greater) vesicoureteral reflux in children. RESULTS: The top-down and C-reactive protein based approaches missed 33% and 29% of cases of high grade vesicoureteral reflux, respectively. CONCLUSIONS: The sensitivity of the top-down approach for detecting high grade vesicoureteral reflux was lower than previously reported. Further study of novel methods to identify children at risk for renal scarring is warranted.


Asunto(s)
Proteína C-Reactiva/análisis , Técnicas de Diagnóstico Urológico , Radiofármacos , Ácido Dimercaptosuccínico de Tecnecio Tc 99m , Reflujo Vesicoureteral/sangre , Reflujo Vesicoureteral/diagnóstico por imagen , Femenino , Humanos , Lactante , Masculino , Cintigrafía , Sensibilidad y Especificidad
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