bluuebunny/crossref_metadata_2025_split huggingface dataset:
Validity, reliability, and feasibility of durometer measurements of scleroderma skin disease in a multicenter treatment trial
Authors: Merkel Peter A. , Silliman Nancy P. , Denton Christopher P. , Furst Daniel E. , Khanna Dinesh , Emery Paul , Hsu Vivien M. , Streisand James B. , Polisson Richard P. , Åkesson Anita , Coppock John , van den Hoogen Frank , Herrick Ariane , Mayes Maureen D. , Veale Douglas , Seibold James R. , Black Carol M. , Korn Joseph H. 
Published: April 2008

AbstractObjectiveTo determine the validity, reliability, and feasibility of durometer measurements of skin hardness as an outcome measure in clinical trials of scleroderma.MethodsSkin hardness was measured during a multicenter treatment trial for scleroderma using handheld digital durometers with a continuous scale. Skin thickness was measured by modified Rodnan skin score (MRSS). Other outcome data collected included the Scleroderma Health Assessment Questionnaire. In a reliability exercise in advance of the trial, 9 investigators examined the same 5 scleroderma patients by MRSS and durometry.ResultsForty‐three patients with early diffuse cutaneous systemic sclerosis were studied at 11 international centers (mean age 49 years [range 24–76], median disease duration 6.4 months [range 0.3–23], and median baseline MRSS 22 [range 11–38]). The reliability of durometer measurements was excellent, with high interobserver intraclass correlation coefficients (ICCs) (0.82–0.92), and each result was greater than the corresponding skin site ICCs for MRSS (0.54–0.85). Baseline durometer scores correlated well with MRSS (r = 0.69, P < 0.0001), patient self‐assessments of skin disease (r = 0.69, P < 0.0001), and Health Assessment Questionnaire (HAQ) disability scores (r = 0.34, P = 0.03). Change in durometer scores correlated with change in MRSS (r = 0.70, P < 0.0001), change in patient self‐assessments of skin disease (r = 0.52, P = 0.003), and change in HAQ disability scores (r = 0.42, P = 0.017). The effect size was greater for durometry than for MRSS or patient self‐assessment.ConclusionDurometer measurements of skin hardness in patients with scleroderma are reliable, simple, accurate, demonstrate good sensitivity to change compared with traditional skin scoring, and reflect patients' self‐assessments of their disease. Durometer measurements are valid, objective, and scalable, and should be considered for use as a complementary outcome measure to skin scoring in clinical trials of scleroderma.
Racial differences in expectations of joint replacement surgery outcomes
Authors: Groeneveld Peter W. , Kwoh C. Kent , Mor Maria K. , Appelt Cathleen J. , Geng Ming , Gutierrez Jennifer C. , Wessel Damaris S. , Ibrahim Said A. 
Published: April 2008

AbstractObjectivePrior studies have indicated racial differences in patients' expectations for joint replacement surgery outcomes. The goal of this study was to measure these differences using a well‐validated survey instrument and to determine if the differences could be explained by racial variation in disease severity, socioeconomic factors, literacy, or trust.MethodsDetailed demographic, clinical, psychological, and social data were collected from 909 male patients (450 African American, 459 white) ages 50–79 years with moderate or severe osteoarthritis (OA) of the hip or knee receiving primary care at 2 veterans affairs medical centers. The previously validated Joint Replacement Expectations Survey was used to assess expectations for pain relief, functional improvement, and psychological well‐being after joint replacement.ResultsAmong knee OA patients (n = 627), the unadjusted mean expectation score (scale 0–76) for African American patients was 48.7 versus 53.6 for white patients (mean difference 4.9, P < 0.001). For hip OA patients (n = 282), the unadjusted mean expectation score (scale 0–72) for African Americans was 45.4 versus 51.5 for whites (mean difference 6.1, P < 0.001). Multivariable adjustment for disease severity, socioeconomic factors, education, social support, literacy, and trust reduced these racial differences to 3.8 points (95% confidence interval [95% CI] 1.2, 6.3) among knee OA patients and 4.2 points (95% CI 0.4, 8.0) among hip patients.ConclusionAmong potential candidates for joint replacement, African American patients have significantly lower expectations for surgical outcomes than white patients. This difference is not entirely explained by racial differences in demographics, disease severity, education, income, social support, or trust.
Short‐term outcome of neuropsychiatric events in systemic lupus erythematosus upon enrollment into an international inception cohort study
Authors: Hanly J. G. , Urowitz M. B. , Su L. , Sanchez‐Guerrero J. , Bae S. C. , Gordon C. , Wallace D. J. , Isenberg D. , Alarcón G. S. , Merrill J. T. , Clarke A. , Bernatsky S. , Dooley M. A. , Fortin P. R. , Gladman D. , Steinsson K. , Petri M. , Bruce I. N. , Manzi S. , Khamashta M. , Zoma A. , Font J. , Van Vollenhoven R. , Aranow C. , Ginzler E. , Nived O. , Sturfelt G. , Ramsey‐goldman R. , Kalunian K. , Douglas J. , Qiufen Qi K. , Thompson K. , Farewell V. 
Published: April 2008

AbstractObjectiveTo determine the short‐term outcome of neuropsychiatric (NP) events upon enrollment into an international inception cohort of patients with systemic lupus erythematosus (SLE).MethodsThe study was performed by the Systemic Lupus International Collaborating Clinics. Patients were enrolled within 15 months of SLE diagnosis and NP events were characterized using the American College of Rheumatology case definitions. Decision rules were derived to identify NP events attributable to SLE. Physician outcome scores of NP events and patient‐derived mental component summary (MCS) and physical component summary (PCS) scores of the Short Form 36 were recorded.ResultsThere were 890 patients (88.7% female) with a mean ± SD age of 33.8 ± 13.4 years and mean disease duration of 5.3 ± 4.2 months. Within the enrollment window, 271 (33.5%) of 890 patients had at least 1 NP event encompassing 15 NP syndromes. NP events attributed to SLE varied from 16.5% to 33.9% using alternate attribution models and occurred in 6.0–11.5% of patients. Outcome scores for NP events attributed to SLE were significantly better than for NP events due to non‐SLE causes. Higher global disease activity was associated with worse outcomes. MCS scores were lower in patients with NP events, regardless of attribution, and were also lower in patients with diffuse and central NP events. There was a significant association between physician outcome scores and patient MCS scores only for NP events attributed to SLE.ConclusionIn SLE patients, the short‐term outcome of NP events is determined by both the characteristics and attribution of the events.
Graded activity for workers with low back pain: Who benefits most and how does it work?
Authors: Staal J. Bart , Hlobil Hynek , Köke Albère J. A. , Twisk Jos W. R. , Smid Tjabe , van Mechelen Willem 
Published: April 2008

AbstractObjectiveTo identify subgroups of workers absent from work due to low back pain who are more or less likely to return to work earlier as a result of a graded activity intervention, and to investigate whether this intervention is effective in reducing pain‐related fears and if so, whether these reductions in pain‐related fears mediate return to work.MethodsA subgroup analysis was conducted on data from a previous randomized controlled trial of 134 Dutch airline workers, which found that a behaviorally‐oriented graded activity intervention was more effective than usual care in stimulating return to work. The subgroup analyses added interaction terms to a Cox regression model that described the relationship between treatment allocation and return to work over 12 months of followup. Furthermore, we studied the effects of graded activity on pain‐related fears and added variables indicating a reduction in pain‐related fears to the model in order to investigate their influence on return to work.ResultsStatistically significant interactions were found for disability, fear‐avoidance beliefs about physical activity, and fear‐avoidance beliefs about work. No indication was found that the reduction in pain‐related fears in the graded activity group mediated more favorable return‐to‐work results in this group.ConclusionWorkers who perceive their disability to be moderate and workers with moderate scores for fear‐avoidance beliefs return to work more rapidly as a result of the graded activity intervention than workers with higher scores. The return to work of workers receiving the graded activity intervention is possibly independent from the reductions in pain‐related fears caused by this intervention.
Interstitial lung disease in polymyositis and dermatomyositis: Longitudinal evaluation by pulmonary function and radiology
Authors: Fathi Maryam , Vikgren Jenny , Boijsen Marianne , Tylen Ulf , Jorfeldt Lennart , Tornling Göran , Lundberg Ingrid E. 
Published: April 2008

AbstractObjectiveTo estimate predictors and long‐term outcome of interstitial lung disease (ILD) in patients with polymyositis (PM) and dermatomyositis (DM).MethodsWe conducted a prospective study in which newly diagnosed PM/DM patients, regardless of clinical symptoms of pulmonary disease, were investigated with repeated chest radiography, high‐resolution computed tomography (HRCT) of the lungs, and pulmonary function test (PFT). Clinical, radiologic, and lung function outcome was based on the last followup results.ResultsTwenty‐three patients with a mean followup period of 35 months were included. Findings on radiographic examination and/or PFT compatible with ILD were recorded in 18 patients (78%). Patients with ILD had lower lung function, higher radiologic scores, and higher creatine kinase values than those without ILD. All patients were treated with high‐dose glucocorticoids and other immunosuppressive agents. Two patients died due to ILD, both with active myositis. During the followup, total lung capacity (TLC) improved in 33%, remained stable in 39%, and deteriorated in 28%. Changes in TLC correlated only partially with HRCT findings, which persisted even after normalizing for lung function.ConclusionILD associated with PM/DM is in most cases mild, chronic, and has a nonprogressive course during immunosuppressive treatment. PFT can be normalized during treatment with immunosuppressive therapy, even if radiologic signs of ILD persist. The course of ILD could not be predicted on the first examination. Therefore, myositis patients with ILD need careful evaluation of clinical features as well as PFT and radiologic features during followup.
Validation of the Health Assessment Questionnaire disability index in patients with gout
Authors: Álvarez‐Hernández Everardo , Peláez‐Ballestas Ingris , Vázquez‐Mellado Janitzia , Terán‐Estrada Leobardo , Bernard‐Medina Ana Guishlaine , Espinoza Jesús , Aceves‐Avila Francisco J. , Goycochea‐Robles María V. , Garza Mario , Ventura Lucio , Burgos‐Vargas Rubén 
Published: April 2008

AbstractObjectiveTo assess the psychometric properties of the Health Assessment Questionnaire (HAQ) disability index (DI) in patients with gout.MethodsThis study was conducted in a multicenter cohort of patients with gout whose data were collected at baseline (time 0) and 6 months later (time 6). Reliability was assessed by test–retest reliability (intraclass correlation coefficient [ICC]) and internal consistency (Cronbach's alpha coefficient). Construct validity was assessed with convergent validity (HAQ DI correlation with Short Form 36 [SF‐36]) and discriminative validity (HAQ DI correlation with clinical features). Sensitivity to change was determined by comparing HAQ DI time 0 versus HAQ DI time 6 (percentage of change, effect size, smallest real difference [SRD], and Guyatt's responsiveness index [GRI]).ResultsWe included 206 patients (96.6% men, mean ± SD age and disease duration 56.3 ± 12.4 years and 9.3 ± 8.5 years, respectively). Of these, 52.4% had joint pain, 22.8% swelling, 32.5% reduced joint mobility, and 36.9% tophi. The mean HAQ DI score was 0.59 ± 0.77 (95% confidence interval [95% CI] 0.49–0.70). ICC (n = 36, evaluations at baseline and 5 days later) was 0.76. Cronbach's alphas were 0.91 (95% CI 0.88–0.92, P = 0.000) for the 20 HAQ DI items and 0.93 (95% CI 0.92–0.94, P = 0.000) for the 8 HAQ DI categories. The HAQ DI correlated in predictable ways with SF‐36 subscales and clinical variables, and discriminated between subgroups with and without any joint pain, swelling, and tophi. Concerning sensitivity to change (n = 167), the difference between HAQ DI time 0 and HAQ DI time 6 was 0.31 ± 0.58 (effect size 0.62, SRD 0.59, and GRI 1.91). ΔHAQ DI correlated with Δpain (r = 0.349, P = 0.000).ConclusionThe HAQ DI is a valid and reliable measure of functioning in patients with gout.
Safety and usefulness of minor salivary gland biopsy: Retrospective analysis of 502 procedures performed at a single center
Authors: Caporali Roberto , Bonacci Eleonora , Epis Oscar , Bobbio‐Pallavicini Francesca , Morbini Patrizia , Montecucco Carlomaurizio 
Published: April 2008

AbstractObjectiveTo analyze the safety of our biopsy technique and the effectiveness of minor salivary gland biopsy (MSGB) for the diagnosis of Sjögren's syndrome (SS) and amyloidosis.MethodsWe conducted a retrospective analysis of 452 patients with suspected SS and 50 with suspected amyloidosis and negative periumbilical fat aspiration analysis who underwent MSGB at a single center. Diagnostic evaluation for SS included Schirmer's test, unstimulated whole salivary flow, detection of antinuclear antibodies and anti‐SSA/SSB, erythrocyte sedimentation rate, C‐reactive protein, IgM rheumatoid factor, and serology for hepatitis C virus. For all biopsy samples, a cumulative focus score on multilevel sections was calculated. SS was diagnosed according to American‐European Consensus Group (AECG) criteria. Histologic evaluation for amyloidosis was performed using Congo red staining and polarized‐light microscopy. Adverse events were recorded on a questionnaire immediately after the procedure and 7 days, 14 days, and 6 months thereafter.ResultsSixty‐four patients (12.7%) reported transient adverse events: 40 paresthesias lasting <7 days, 17 paresthesias lasting <14 days, 27 cases of local swelling, and 8 external hematoma. One patient has had local paresthesia for 2 years. A total of 498 (99.2%) samples provided adequate material for histologic analysis. Of 452 patients evaluated for SS, 378 were finally evaluated. Ninety‐three patients (24.5%) had a cumulative focus score ≥1, and 87 (94.5%) of 93 satisfied the AECG criteria. Classification of SS was possible for 124 (32.8%) of 378 patients. In 51 (41%) of 124, MSGB was essential to reach the number of criteria needed for classification. Of 50 patients evaluated for amyloidosis, 10 (20%) had positive Congo red staining.ConclusionMSGB is a simple, safe, and reliable tool for the diagnosis of SS and amyloidosis, and therefore is suitable for more extensive application.
Thinking about movement hurts: The effect of motor imagery on pain and swelling in people with chronic arm pain
Authors: Moseley G. Lorimer , Zalucki Nadia , Birklein Frank , Marinus Johan , van Hilten Jacobus J. , Luomajoki Hannu 
Published: April 2008

AbstractObjectiveChronic painful disease is associated with pain on movement, which is presumed to be caused by noxious stimulation. We investigated whether motor imagery, in the absence of movement, increases symptoms in patients with chronic arm pain.MethodsThirty‐seven subjects performed a motor imagery task. Pain and swelling were measured before, after, and 60 minutes after the task. Electromyography findings verified no muscle activity. Patients with complex regional pain syndrome (CRPS) were compared with those with non‐CRPS pain. Secondary variables from clinical, psychophysical, and cognitive domains were related to change in symptoms using linear regression.ResultsMotor imagery increased pain and swelling. For CRPS patients, pain (measured on a 100‐mm visual analog scale) increased by a mean ± SD of 5.3 ± 3.9 mm and swelling by 8% ± 5%. For non‐CRPS patients, pain increased by 1.4 ± 4.1 mm and swelling by 3% ± 4%. There were no differences between groups (P > 0.19 for both). Increased pain and swelling related positively to duration of symptoms and performance on a left/right judgment task that interrogated the body schema, autonomic response, catastrophic thoughts about pain, and fear of movement (r > 0.42, P < 0.03 for all).ConclusionMotor imagery increased pain and swelling in patients with chronic painful disease of the arm. The effect increased in line with the duration of symptoms and seems to be modulated by autonomic arousal and beliefs about pain and movement. The results highlight the contribution of cortical mechanisms to pain on movement, which has implications for treatment.
Promotion Time Models with Time‐Changing Exposure and Heterogeneity: Application to Infectious Diseases
Authors: Tournoud Maud , Ecochard René 
Published: April 2008

AbstractPromotion time models have been recently adapted to the context of infectious diseases to take into account discrete and multiple exposures. However, Poisson distribution of the number of pathogens transmitted at each exposure was a very strong assumption and did not allow for inter‐individual heterogeneity. Bernoulli, the negative binomial, and the compound Poisson distributions were proposed as alternatives to Poisson distribution for the promotion time model with time‐changing exposure. All were derived within the frailty model framework. All these distributions have a point mass at zero to take into account non‐infected people. Bernoulli distribution, the two‐component cure rate model, was extended to multiple exposures. Contrary to the negative binomial and the compound Poisson distributions, Bernoulli distribution did not enable to connect the number of pathogens transmitted to the delay between transmission and infection detection. Moreover, the two former distributions enable to account for inter‐individual heterogeneity. The delay to surgical site infection was an example of single exposure. The probability of infection was very low; thus, estimation of the effect of selected risk factors on that probability obtained with Bernoulli and Poisson distributions were very close. The delay to nosocomial urinary tract infection was a multiple exposure example. The probabilities of pathogen transmission during catheter placement and catheter presence were estimated. Inter‐individual heterogeneity was very high, and the fit was better with the compound Poisson and the negative binomial distributions. The proposed models proved to be also mechanistic. The negative binomial and the compound Poisson distributions were useful alternatives to account for inter‐individual heterogeneity. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Youden Index and Optimal Cut‐Point Estimated from Observations Affected by a Lower Limit of Detection
Authors: Ruopp Marcus D. , Perkins Neil J. , Whitcomb Brian W. , Schisterman Enrique F. 
Published: April 2008

AbstractThe receiver operating characteristic (ROC) curve is used to evaluate a biomarker's ability for classifying disease status. The Youden Index (J), the maximum potential effectiveness of a biomarker, is a common summary measure of the ROC curve. In biomarker development, levels may be unquantifiable below a limit of detection (LOD) and missing from the overall dataset. Disregarding these observations may negatively bias the ROC curve and thus J. Several correction methods have been suggested for mean estimation and testing; however, little has been written about the ROC curve or its summary measures. We adapt non‐parametric (empirical) and semi‐parametric (ROC‐GLM [generalized linear model]) methods and propose parametric methods (maximum likelihood (ML)) to estimate J and the optimal cut‐point (c *) for a biomarker affected by a LOD. We develop unbiased estimators of J and c * via ML for normally and gamma distributed biomarkers. Alpha level confidence intervals are proposed using delta and bootstrap methods for the ML, semi‐parametric, and non‐parametric approaches respectively. Simulation studies are conducted over a range of distributional scenarios and sample sizes evaluating estimators' bias, root‐mean square error, and coverage probability; the average bias was less than one percent for ML and GLM methods across scenarios and decreases with increased sample size. An example using polychlorinated biphenyl levels to classify women with and without endometriosis illustrates the potential benefits of these methods. We address the limitations and usefulness of each method in order to give researchers guidance in constructing appropriate estimates of biomarkers' true discriminating capabilities. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Regression Analysis of Multivariate Interval‐Censored Failure Time Data with Application to Tumorigenicity Experiments
Authors: Tong Xingwei , Chen Man‐Hua , Sun Jianguo 
Published: April 2008

AbstractThis paper discusses multivariate interval‐censored failure time data that occur when there exist several correlated survival times of interest and only interval‐censored data are available for each survival time. Such data occur in many fields. One is tumorigenicity experiments, which usually concern different types of tumors, tumors occurring in different locations of animals, or together. For regression analysis of such data, we develop a marginal inference approach using the additive hazards model and apply it to a set of bivariate interval‐censored data arising from a tumorigenicity experiment. Simulation studies are conducted for the evaluation of the presented approach and suggest that the approach performs well for practical situations. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Solid‐State Photochemical [2+2] Cycloaddition in a Hydrogen‐Bonded Metal Complex Containing Several Parallel and Crisscross CC bonds
Authors: Peedikakkal Abdul Malik Puthan , Vittal Jagadese J. 
Published: April 2008

AbstractOne‐dimensional hydrogen‐bonded complex [Zn(bpe)2(H2O)4](NO3)2⋅8/3 H2O⋅2/3 bpe (1, bpe=4,4′‐bipyridylethylene) containing coordination complex cations [Zn(bpe)2(H2O)4]2+ with parallel and crisscross double bonds undergoes photochemical [2+2] cycloaddition in the solid state and produces tetrakis(4‐pyridyl)cyclobutane (tpcb) in up to 100 % yield with rctt‐tpcb (2 a) as major and rtct‐tpcb (2 b) as minor product. The bpe ligands with crisscross conformation of CC bonds appear to undergo pedal‐like motion prior to photodimerization. Grinding single crystals to powder accelerates the pedal motion of crisscrossed olefins in the bpe ligands to parallel alignment and provides the rctt‐cyclobutane stereoisomer 2 a quantitatively. In addition, 100 % photodimerization of ground 1 indicates that the free bpe ligands, which are remote from each other in a pool of water, and NO3− ions moved toward each other to give a mixture of rctt‐ and rtct‐tpcb isomers.