Effect of HIV-1 genetic diversity on HIV-1 RNA quantification in plasma: comparative evaluation of three commercial assays.
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Cells, Cultured↗
Biomedical subjects
J Coste
Publications and source records attributed to J Coste.
Optimal discriminant analysis for ordinal responses.
Optimal classification formulation is adapted to the context of discrimination when the response is ordinal. The resulting method, optimal discriminant analysis for ordinal responses (ODAO), is presented and compared with two reference discrimination techniques used in this context (proportional-odds ordinal logistic regression and normal discrimination) using a study of prognosis following burn injuries and simulated data. The ODAO method clearly outperforms both reference methods in terms of classification accuracy (in training and validation samples), robustness to outliers, simplicity of use and applicability in clinical settings. ODAO is a promising method for improving classification performance in discrimination with ordinal responses and merits further investigation.
Adult↗
Construction of composite scales for risk assessment in epidemiology: an application to ectopic pregnancy.
Composite scoring systems that combine information contained in a number of risk factors are being used increasingly in clinical practice, planning, and health risk appraisal. The authors propose a methodological framework for the construction and validation of a composite measurement scale to assess the risk, considered as a continuous phenomenon, of developing a particular disease or outcome. This framework integrates several statistical methods, especially those concerning model fitting, coefficient rounding, and validation strategy. It also uses psychometric methods, addressing important measurement properties such as measurement level, content and construct validity, and reliability of the constructed scale. The proposed framework is illustrated by application to the construction of a composite scale for measurement of the risk of ectopic pregnancy.
Adolescent↗
Reliability of tuberculin skin test measurement.
BACKGROUND: Important management decisions depend on results of the tuberculin skin test. However, the test is subject to several potential errors, and its reliability has not been adequately studied. OBJECTIVE: To ascertain the reliability of tuberculin skin testing. DESIGN: Cross-sectional study. SETTING: University hospital. PARTICIPANTS: 96 persons who received a tuberculin skin test. MEASUREMENTS: Ballpoint-pen and palpation measures of induration. RESULTS: Global intra- and interobserver reliability coefficients of the ballpoint-pen technique were high. Five percent of the time, however, a second measurement by the same observer could be at least 2.7 mm less to 3.0 mm more than the first measurement and the measurement from the second observer could be at least 3.4 mm less to 3.7 mm more than the measurement from the first observer. This could lead to the reclassification of a positive test result as negative or vice versa. The area of imprecision was 38% less broad for the ballpoint-pen technique than for the palpation technique. CONCLUSION: Reading of tuberculin skin tests may frequently result in misclassifications when measurements are close to the cutoff point that separates negative from positive results.
Cross-Sectional Studies↗
The AIMS2-SF: a short form of the Arthritis Impact Measurement Scales 2. French Quality of Life in Rheumatology Group.
OBJECTIVE: To develop a short form of the Arthritis Impact Measurement Scales 2 (AIMS2) questionnaire, preserving content validity as the priority criterion. METHODS: A 2-step reduction procedure was used: 1) Delphi technique, with 1 panel of patients and 1 panel of experts each selecting 1 set of items independently; and 2) nominal group technique, where members of both panels reached consensus on the final selection of items, using information derived from item analysis. Psychometric properties of the AIMS2-Short Form (AIMS2-SF) and AIMS2 were compared using data from a cohort of 127 rheumatoid arthritis patients who completed the AIMS2 twice prior to the initiation of methotrexate (MTX) treatment and 3 months post-initiation of MTX treatment. RESULTS: The 2 panels reached consensus on a 26-item AIMS2-SF (54.4% reduction from the AIMS2). Factor analysis showed preservation of the 5-component structure. Convergent validity (Physical and Symptom components with clinical variables: r = 0.24-0.59), test-retest reproducibility (intraclass correlation coefficient >0.7), and sensitivity to change at 3 months (standardized response mean 0.36-0.8, except Social Interaction component [0.08]) were very close to the values for the original AIMS2. CONCLUSION: The AIMS2-SF is a shorter version of the AIMS2 (i.e., available in 2-page format) and has psychometric properties similar to those of the AIMS2.
Activities of Daily Living↗
Anterior cruciate ligament reconstruction by mini-arthrotomy.
We present 50 consecutive patients with chronic anterior cruciate deficiency treated by reconstruction of the ligament through a limited arthrotomy using the middle third of the patellar tendon as a graft. The patients were all men with a mean age of 26 years (range 17 to 36 years) with an average follow up of 24 months. There were good or excellent results as measured by the Lysholm score in 41, and in 27 with the ARPEGE score. Movements were full in 46 and retropatellar pain was experienced by 4.
Adolescent↗
Methodological approaches to shortening composite measurement scales.
Composite measurement scales (CMSs) have contributed to improving the measurement of complex medical phenomena such as physical and psychological functioning or health-related quality of life. However, their use in patient care and research is often limited by their length and excessive respondent burden. In such situations, short instruments should be made available. Efforts to develop short instruments have largely focused on shortening existing instruments. To investigate the methodology currently used in the shortening of CMS, we assessed 42 studies reported in medical, psychological, and educational journals between 1984 and 1994. A number of methodological and statistical considerations important in the CMS shortening procedure were found to have been ignored or neglected by authors developing short forms from existing CMS. Serious flaws appear mainly to result from inadequate conceptualization of the shortening process, and inappropriate use and excess credit given to statistical techniques used to select items to be retained in short forms. When performed, the assessment of measurement properties of the short form was often inappropriate, and cross validation studies were seldom conducted. We propose recommendations for shortening existing CMS, to help authors and investigators develop and choose, respectively, shortened measurement instruments. These recommendations address the preliminary choice of the original CMS to be shortened, and the two successive phases to be considered in the development of short forms: the shortening process itself, where items are selected, and the validation of the shortened CMS, which should be conducted independently using independent subject samples.
Data Collection↗
Prognostic value of thoracic recurrent nerve nodal involvement in esophageal squamous cell carcinoma.
BACKGROUND: The determination of a simple and reliable prognostic factor that allows identification of patients at high risk of early cancer recurrence and subsequent death after resection of esophageal carcinoma should contribute to more accurate management of patients suffering from this disease. STUDY DESIGN: The aim of this study was to assess the prognostic value of thoracic recurrent nerve nodal involvement after curative resection of esophageal squamous cell carcinoma. The prognostic importance of gender, age, tumor penetration, and extent of lymph node involvement was evaluated in 55 patients after curative resection of esophageal squamous cell carcinoma. RESULTS: Thirty-four of 55 patients (62%) had nodal metastases and 10 of 55 (18%) had thoracic recurrent nerve nodes involved. The median overall survival was 28 months. By univariate analysis, survival was higher in association with the absence of adventitial invasion (p = 0.04), of nodal involvement (p = 0.03), and of thoracic recurrent nerve nodal involvement (p = 0.0001). In a Cox proportional hazards regression model, thoracic recurrent nerve nodal involvement appeared the strongest predictive factor (adjusted hazard ratio 8.4 (3.0-23.7)). CONCLUSIONS: Assessment of thoracic recurrent nerve nodes is appropriate to identify patients who are at high risk of disease-related death after surgical resection.
Adult↗
GEMHEP multicenter quality control study of PCR detection of GB virus C/hepatitis G virus RNA in serum.
PCR is, to date, the only available tool for the detection of GB virus C (GBV-C) and hepatitis G virus (HGV) RNAs. Twenty-two French laboratories participated in a quality control study to assess the sensitivity and specificity of their procedures. The panel included 13 positive controls and 7 negative controls. The laboratories used either in-house PCR techniques adapted from the literature or partly standardized commercial tests. Three laboratories performed faultlessly with the entire panel. Most laboratories had excellent specificity (100% in 20 of 22 laboratories). Sensitivity was acceptable (85 to 100%) in 15 centers and insufficient (38 to 77%) in 7. As with nonstandardized in-house PCR, the commercial assays gave discrepant performances in different laboratories. These results suggest that laboratories willing to use PCR for detection of GBV-C/HGV RNA for research or diagnostic purposes should participate in multicenter quality control trials.
Flaviviridae↗
Growth hormone testing for the diagnosis of growth hormone deficiency in childhood: a population register-based study.
Evaluation of GH secretion using pharmacological GH stimulation tests (GHST) remains a current practice, although the reliability of GHST has been questioned, and many pitfalls have been pointed out. We have analyzed all of the 6373 GH stimulation tests that led to the initiation of GH therapy in 3233 children treated in France from 1973-1989. Tests and GH measurements were performed by individual centers and collected by the Association France-Hypophyse. GH deficiency (GHD) was due to craniospinal irradiation (11%), was due to organic causes or associated with multiple deficiencies (22%), or was considered idiopathic (65%); 2% of the patients were considered non-GHD. Eleven different pharmacological tests were used, and 62 of the 66 theoretical pairs of tests were used at least once. The most frequent combination of tests (ornithine in one instance and insulin in another) was used in 12.7% of patients. The reliability of the GH peak measured by comparing the results of 2 tests in the same patient was poor, as measured by intraclass correlation coefficients below 0.8. Multivariate analysis identified several parameters positively or negatively associated with peak plasma GH: calendar year of initiation of treatment, etiology of GHD, height SD score, bone age SD score, puberty, weight SD score, genetic target height SD score, and the nature of the pharmacological agent used. We believe that several of these factors (weight SD score, genetic target height SD score, and nature of the agent) identify biases in the diagnosis of GHD. We conclude that GHST should be performed with a very limited number of agents, interpreted after the establishment of reference values in age-matched normal children, and associated with other clinical and biochemical parameters for establishing the diagnosis of GHD.
Adolescent↗
Prediction of articular destruction in rheumatoid arthritis: disease activity markers revisited.
OBJECTIVE: To assess the predictive value for joint damage progression of commonly used disease activity or process measures in rheumatoid arthritis (RA). METHODS: Seventy-two patients fulfilling the American Rheumatism Association criteria for RA were assessed twice yearly for 2 years. Primary outcome variables were progression of articular destruction, evaluated by Sharp's method, for 6, 12, 18, and 24 month periods. RESULTS: Regression analysis, using random effects linear models, showed that only C-reactive protein, alpha 1-acid glycoprotein, iron, and erythrocyte sedimentation rate were significantly, but not independently, associated with 6 month radiographic progression. Traditional clinical measures were not predictive. No assessed marker was able to predict longer term outcome (12 or 18 month joint damage progression). Recent onset disease and older age were also associated with more severe radiographic progression. CONCLUSION: The lack of association between clinical measures and laboratory markers as predictors of the progression of articular destruction is further evidence of the need to reconsider processes and outcomes in RA. This study also suggests that clinical measures and laboratory markers probably do not reflect the same underlying process, arguing against gathering these measures under the same heading of "disease activity measures".
Adult↗
Meta-analysis--"does one bad apple spoil the barrel?".
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Female↗
The continuing challenge of predictive factors in rheumatoid arthritis.
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Arthritis, Rheumatoid↗
[Ectopic pregnancy recurrence: role of gynecologic, obstetric, contraceptive and smoking history].
The purpose of this study, based on data from the register of ectopic pregnancy in Auvergne (centre of France), is to identify risk factors of recurrence of ectopic pregnancy (EP). The social characteristics, gynaecological, surgical and reproductive history and conditions of the conception of 96 women with a previous EP were compared to those for 566 women without previous EP. Risk factors associated with the management of the first EP could not be analysed with the data available. Several factors increased the risk of recurrence: previous proved or suspected salpingitis (OR = 3.6), maternal smoking (OR = 1.7 to 2.0 according to the consumption level), maternal age greater than 30 (OR = 2.0), and previous recurrent spontaneous abortions (SA) among childless women (OR = 3.4 to 11.9 according to the number of SA). The last of these factors may reflect another unknown risk factors common to recurrent SA and recurrent EP (for example hormonal or karyotype factors). Previous use of intra uterine device is associated with a decrease in the risk of recurrence of EP (OR = 0.27), but this contraceptive method should be considered as an indicator of good fertility rather than as a protective factor for EP recurrence.
Abortion, Spontaneous↗
Comparative evaluation of three assays for the quantitation of human immunodeficiency virus type 1 RNA in plasma.
Reverse transcriptase-coupled polymerase chain reaction (Amplicor HIV-1 Monitor), the branched DNA (bDNA) method (Quantiplex HIV-1 RNA) and the nucleic acid sequence-based assay (NASBA HIV-1 RNA QT) were comparatively evaluated for the quantitation of human immunodeficiency virus type 1 (HIV-1) RNA in plasma. Among 60 plasma specimens from HIV-1 infected patients, HIV-1 RNA was detected in 56 by Amplicor (sensitivity, 93.3%), in 41 by bDNA (sensitivity, 68.3%), and in 60 by NASBA (sensitivity, 100%). HIV-1 RNA was not detected by any of these methods in 34/34 plasma specimens from HIV-1-seronegative blood donors (specificity, 100%). The HIV-1 RNA levels as determined by the different methods were correlated significantly. The frequency of concordant results (log difference < 0.50) was 80.4% between Amplicor and NASBA, 77.5% between Amplicor and bDNA, and 58.6% between bDNA and NASBA. After initiation of antiviral therapy, HIV-1 RNA level variations observed with the three methods were similar. HIV-1 RNA levels were inversely correlated with the CD4+ T cell counts, whereas no correlation was found with HIV-1 p24-antigen levels. When the methods were evaluated for reproducibility, coefficients of variation ranged from 11% to 40% for Amplicor, from 6% to 35% for bDNA, and from 13% to 62% for NASBA. Quantitation of HIV-1 RNA in culture supernatants from HIV-1 subtype A to H strains showed that bDNA can be used to quantitate RNA from all HIV-1 subtypes, whereas Amplicor failed to detect RNA from subtype A strains and NASBA subtype G strains.
CD4 Lymphocyte Count↗
Sicca syndrome associated with hepatitis C virus infection.
OBJECTIVE: To determine the prevalence of hepatitis C virus (HCV) infection in patients with sicca syndrome, and to determine the clinical, immunologic, and genetic characteristics of sicca syndrome associated with HCV. METHODS: We conducted a prospective study in a university hospital immunology-rheumatology department. Sixty-two consecutive patients with sicca syndrome according to the European criteria for Sjögren's syndrome were included. HCV infection was diagnosed in patients with positive recombinant immunoblot assay findings and the presence of viral RNA in serum and saliva. Rheumatoid factor (RF), cryoglobulins, antinuclear antibodies, and anti-SS-A/SS-B antibodies were sought. HLA typing was performed on all patients. RESULTS: The prevalence of HCV infection in patients with sicca syndrome was 19%. The incidence of neurologic involvement was significantly increased in patients with sicca syndrome associated with HCV infection (24% versus 4%; P < 0.03), as was elevations in transaminase levels (87.5% versus 16%; P < 0.0001). RF and cryoglobulins were more frequent in HCV-positive sicca syndrome patients (62% versus 30%; P < 0.03, and 56% versus 10%; P < 0.001, respectively). In contrast, anti-SS-A/SS-B antibodies were present in 38% of HCV-negative sicca syndrome patients, but in only 1 HCV-positive sicca syndrome patient (P < 0.01). No significant difference in HLA type was observed. Viral RNA was present in the saliva of 83% of HCV-positive sicca syndrome patients, but in none of the HCV-negative sicca syndrome patients. CONCLUSION: We observed a high prevalence of HCV infection in our patients with sicca syndrome. HCV-positive sicca syndrome patients had specific clinical characteristics and were seronegative for SS-A/SS-B antibodies. Moreover, HCV RNA was present in the saliva of patients with HCV-associated sicca syndrome.
Antibodies↗
[Preoperative hemodilution by erythrocytapheresis with homologous blood saving in total hip arthroplasty].
OBJECTIVES: To compare three techniques for decreasing homologous blood requirements in total hip arthroplasty (THA), including preoperative autologous donation (PAD), preoperative acute normovolaemic haemodilution with erythrocytapheresis (erythro) and intraoperative normovolaemic haemodilution (haemo). STUDY DESIGN: Prospective clinical trial. PATIENTS: The study included 45 patients scheduled for THA, under general anaesthesia and operated on by the same surgeon. The patients were allocated into three groups of 15 each. METHODS: Blood loss was assessed, during surgical procedure, by the weight of sponges and, the amount of blood collected in the suction bottles during and after surgery. The haemoglobin concentration was measured at the time of preoperative assessement (d-30), just prior to surgery (d-1), in the recovery room (d+3h), and 1, 3, and 8 days later (d8). The transfusion end-point in the three groups was to obtain a haemoglobin concentration of 100 g.L-1 from d+3h until d8. Every pack of red blood cells transfused was weighed and its haematocrit assessed to determine the accurate volume of red blood cells. RESULTS: In the three groups haemoglobin concentration was similar from d+3h until d8. In the PAD group, no patient required homologous blood transfusion. There was no significant difference between the two other groups in the mean volume of homologous red blood cells required (308 +/- 197 mL in erythro group and 331 +/- 202 mL in the haemo group, respectively). The intraoperative blood loss was significantly higher (P = 0.001) in the erythro group: 914 +/- 305 mL vs 665 +/- 263 in the PAD group and 512 +/- 146 mL in the haemo group, respectively. There was an inverse correlation between haematocrit at d-1 and intraoperative bleeding (r = -0.7) (P = 0.0001). The distribution of the points was fitted as an exponential curve. CONCLUSIONS: In THA, PAD is obviously the best technique to avoid homologous blood transfusion. However, when PAD is not feasible, removal of blood prior to surgery does not decrease requirements of homologous blood, as intraoperative blood loss is higher. Our results strongly question the use of major haemodilution during a surgical procedure exposing a major blood loss.
Aged↗
Predicting mortality in adult burned patients: methodological aspects of the construction and validation of a composite ratio scale.
This article describes the methodology of construction and validation of a composite measurement scale (CMS) to predict the risk of death for burned patients, with severity of burn considered as a continuous phenomenon. Three large data sets of burned patients hospitalized in France were analyzed. Logistic regression was used to construct a prognostic model, based on age and initial evaluation of total body surface area burned. The resulting model appears to be a valid clinical tool for predicting the risk of death. In addition, the devised CMS has satisfactory content and construct validity and reliability, and provides a high measurement level (logistic ratio level). Moreover, its simplicity of use (the score is integer based) is appropriate for the daily activities of burn unit physicians, emergency medical technicians, and public health professionals.
Adult↗