Search PubMed⌕ Search

Biomedical subjects

B Thirion

Publications and source records attributed to B Thirion.

At least 19 recordsLinked to original sources
PubMed2003

Level of evidence as a future gold standard for the content quality of health resources on the internet.

OBJECTIVE: An assessment of the quality of health information on the Internet is an absolute necessity. In this study 'sensitive' information was defined as information found in documents published on the Internet, which could be used in a medical decision. For sensitive information, the main criterion chosen for the quality of the information was an indication of the level of evidence. A survey was conducted using the CISMeF health catalogue to assess how often a score of the level of evidence is mentioned in the information accessible on the Internet in French-language health resources. METHODS: Since 1999, members of the CISMeF team have systematically been searching for all documents containing 'sensitive' information and verifying whether the level of evidence was explicitly indicated as a score at least once in the document. RESULTS: As of June 2001, 10,190 resources were included in CISMeF; including 2964 textual 'sensitive' resources (29.1%). Out of all these resources, only 4.7% (95% confidence interval: 4.0 - 5.5%) indicated the level of evidence. A statistically significant difference in the prevalence of indicating the level of evidence according to resource types (e.g., 18.1% for guidelines compared to 0.0% for teaching material), year of publication (almost three times greater in 1997-2001 compared with 1990-1996) and publishers was observed. CONCLUSION: As the number of people accessing the growing amount of information on the Internet is increasing daily, publishers have an ethical obligation to inform their readers about the validity of 'sensitive' information their sites contain. However, the vast majority of the French language Internet resources that were surveyed do not mention a score of the level of evidence for their sensitive information.

Consensus↗
PubMed2001

Doc'CISMEF: a search tool based on "encapsulated" MeSH thesaurus.

In the year 2000, the Internet became a major source of health information for the health professional and the Netizen. The objective of Doc'CISMeF (D'C) was to create a powerful generic search tool based on an structured information model which â encapsulates' the MeSH thesaurus to index and retrieve quality health resources on the Internet. To index resources, D'C uses four sections in its information model: 'meta-term', keyword, subheading, and resource type. Two search options are available: simple and advanced. The simple search requires the end-user to input a single term or expression. If this term belongs to the D'C information structure model, it will be exploded. If not, a full-text search is performed. In the advanced search, complex searches are possible combining Boolean operators with meta-terms, keywords, subheadings and resource types. D'C uses two standard tools for organising information: the MeSH thesaurus and the Dublin Core metadata format. Resources included in D'C are described according to the following elements: title, author or creator, subject and keywords, description, publisher, date, resource type, format, identifier, and language.

Abstracting and Indexing↗
PubMed2001

Reading factor: a bibliometric tool to manage a virtual library.

UNLABELLED: Among the many bibliometric criteria used to evaluate biomedical journals, the impact factor is the most commonly used. Despite its limitations, it quantifies the influence of a journal on secondary publications. It does not however evaluate the practical usefulness of primary documents. Usefulness is field-related and varies greatly among specialities. We introduce a new bibliographic criterion, the "reading factor", and define it as the ratio between the number of electronic consultations of a particular journal (i.e., number of clicks on a hyper-link) and the mean number of electronic consultations of all the journals studied (itself calculated by dividing the total number of electronic accesses by the number of journals in the database). We describe its observed distribution, relative to that of the impact factor, based on electronic consultation records from our University Hospital medical digital library, where full-text electronic versions of 45 major biomedical journals have been available since December 1997. From this analysis we found no correlation between the 1999 reading factor and the 1998 impact factor of these 45 journals, and we observed a dramatic change in the hierarchy of journals upon using the reading factor as the yardstick rather than the impact factor. Moreover, we describe how using the reading factor has helped in managing the collection of our University Hospital's virtual library. The selection of journals to be discarded from the virtual library for the year 2001 was based on journals' RF values and this process will repeated over the coming years. The reading factor also permits a cost-analysis of a virtual library. CONCLUSION: The measurement of the reading factor is highly automated, practical and efficient. It appears as a new tool for electronic collection management by librarians, well fitting with economical data.

Bibliometrics↗
PubMed2000

How to select publications on occupational health: the usefulness of Medline and the impact factor.

OBJECTIVES: Publications in the field of occupational health appear in various journals, including those of other medical specialties. This complicates the follow up of literature for specialists in this field. On the basis of Medline and the impact factor, this diversity was assessed, and a cost effective method for selecting the most pertinent journals in the practice of occupational health was proposed. METHODS: A Medline search identified all the articles published in 1998 with occupational diseases or occupational exposures as the main topic. These articles were classified based on the journals in which they appeared. The journals were then compared according to their subject area, the number of articles that were published in the fields studied, and their impact factor. RESULTS: The search retrieved 2247 articles, published in 577 different journals in 1998. Each journal published between one and 105 articles during this period (mean 3.89). However, only 1.4% of the journals accounted for more than 25% of the total articles published. More than half of the articles were published in journals dealing with general practice or medical specialties other than occupational health. Only 66% of retrieved journals had an impact factor, and more than 80% of the articles were published in journals with an impact factor <2. CONCLUSION: Simply following up occupational health journals is not sufficient to meet the requirements of the occupational health professional. Moreover, the use of the impact factor cannot be considered as a reliable research tool to assess follow up. Two lists of eight and 38 journals were thus set up. They permit a literature coverage of 27% and 52% respectively in the specific fields studied, and this seems to be the optimal compromise between time and literature covered. Lastly, practical procedures are suggested to follow up literature and obtain abstracts from selected journals on the internet.

Bibliometrics↗
PubMed2000

A study comparing centralized CD-ROM and decentralized intranet access to MEDLINE.

OBJECTIVE: The purpose of this study was to evaluate the efficacy of a decentralized intranet access in each medical department as opposed to centralized unique MEDLINE access in the medical library. DESIGN: A two-phase questionnaire to evaluate MEDLINE use was given to junior and senior physicians at Rouen University Hospital (RUH). Phase I (August-October 1996) corresponded to a time period when centralized access was the only means of access available and phase II (August-October 1997) to a time period following the introduction of decentralized intranet access. RESULTS: A total of 168 physicians filled out at least one phase of the questionnaire, among whom 123 (73%) filled out both phases. Use of MEDLINE significantly increased in 1997 (average of 10.2+/-1.1 searches in three months) versus 1996 (average of 4.9+/-0.7 searches in three months, P<0.0001). The aim of searches changed, becoming significantly more care oriented in phase II (P<0.0001). The number of searches performed by the physicians alone increased (P<0.0001) and searches performed by the librarian decreased (P<0.0001) in phase II. The method of searches also changed, as searches by author (P< 0.0001), by journal (P = 0.0042), and by free word (P = 0.0027) increased in phase II. Knowledge of the following concepts of MEDLINE significantly increased: explosion (P<0.0001), scope note (P<0.0001), Abridged Index Medicus (AIM) journals (P<0.0001), Medical Subject Headings (MeSH) qualifier (P<0.0001), and focus (P<0.0001). CONCLUSION: A decentralized intranet access to MEDLINE increased the number of searches and knowledge of this bibliographic database. MEDLINE intranet access modified the purpose and the methods of searching.

CD-ROM↗
PubMed2000

CISMeF: a structured health resource guide.

In 1999, the Internet has become a major source of health information. The objective of CISMeF is to catalogue and index the main French-speaking health resources. In September 1999, the number of indexed resources totaled over 7,100 with a mean of 75 new sites per week. CISMeF uses two standard tools for organizing information: the Medline bibliographic database MeSH thesaurus and the Dublin Core metadata format. Resources included in CISMeF are described by the following: title, author or creator, subject and keywords, description, publisher, date, resource type, format, identifier, and language. To index resources, CISMeF uses five levels of hierarchy: "meta-term", category, keyword, subheading, and resource type. CISMeF contains a thematic index, including medical specialities and an alphabetic index. CISMeF respects the Net Scoring, criteria to assess the quality of health information on the Internet. The CISMeF project offers a valuable tool for the French-speaking health community: 2,500 computer users visit the Web site each working day.

Abstracting and Indexing↗
PubMed1999

A new approach for clinical biological assay comparison and standardization: application of principal component analysis to a multicenter study of twenty-one carcinoembryonic antigen immunoassay kits.

BACKGROUND: Principal component analysis (PCA) is a powerful mathematical method able to analyze data sets containing a large number of variables. To our knowledge, this method is applied here for the first time in the field of medical laboratory analysis. METHODS: PCA was used to evaluate the results of a blind comparative study of 21 carcinoembryonic antigen (CEA) reagent kits used to determine CEA concentration in a panel of sera from 80 patients. RESULTS: The mathematical technique first eliminated the variations attributable to the use of different calibrators. The PCA representation then gave a global view of the dispersion of the kits and allowed the identification of a main homogeneous group and of some discrepant kits. CONCLUSIONS: PCA applied to the in vitro diagnostic reagent field could contribute to the standardization process and improve the quality of medical laboratory analyses. A standardization method using a panel of patient sera is proposed.

Biomarkers, Tumor↗
PubMed1999

CISMeF: cataloque and index of French speaking health resources.

In 1999, the Internet has become a major source of health information. The objective of CISMeF is to catalogue and index the main French-speaking sites and documents concerning health. Currently, the number of resources already totalled over 6,100 with a mean of 75 new sites each week. CISMeF contains a thematic index, including medical specialities and an alphabetic index. CISMeF uses two standard tools for organising information: the MeSH (Medical Subject Heading) thesaurus from the Medline bibliographic database (National Library of Medicine) and the Dublin Core metadata format. A brief description of the site is systematically added. CISMeF respects the Net Scoring, criteria to assess the quality of health information on the Internet. The CISMeF project fulfils a valuable tool for the French-speaking health community: 2,500 machines visit the Web site each working day.

Abstracting and Indexing↗
PubMed1998

Assessment of bibliographic databases performance in information retrieval for occupational and environmental toxicology.

OBJECTIVE: To determine the efficiency of the major bibliographic databases by assessing the percentage of references among the total literature available that can be retrieved from each database. We also evaluated the best database combinations to carry out an exhaustive search. METHODS: BIOSIS, EMBASE, MEDLINE, NIOSH-TIC, and TOXLINE were searched on two topics: allergy to latex and asbestos and mesothelioma, in the title, abstract, or keywords (textwords). This search was performed for the years 1994 and 1995. All the records were classified by journal and author's name and were verified for each record whether or not it was indexed in each database. Statistical analysis was performed with chi 2 test. RESULTS: 777 articles in 510 issues were found. The efficiency of each database (percentage of articles recovered) and of combinations varied between 11% and 63% for one database and between 42% and 86% for a combination of two databases. The reasons why these differences exist between databases, and within a database, between two different subjects or two different years are reported. CONCLUSION: Firstly, it is not advisable to assert that a bibliography is complete when only one database is searched. Secondly, the efficiency of the databases may be quite different. Finally, it is suggested that the best way to be as exhaustive as possible is to search two or more databases-for example, in EMBASE and TOXLINE, or to a lesser extent EMBASE and MEDLINE. This seems to be the best compromise solution between time consumed for searching and efficiency.

Asbestos↗
PubMed1994

CYFRA 21-1, a sensitive and specific new tumour marker for squamous cell lung cancer. Report of the first European multicentre evaluation. CYFRA 21-1 Multicentre Study Group.

The present study was designed to determine whether CYFRA 21-1, measuring cytokeratin 19, could be a specific and sensitive tumour marker for non-small cell lung cancer (NSCLC). Serum measurements were made at diagnosis in 2250 patient samples by an immunoradiometric "sandwich type" assay, using two cytokeratin 19 specific monoclonal antibodies. Among healthy individuals (n = 711) and patients with benign lung disease (n = 546), 95 percentiles were 1.2 and 2.95 ng/ml, respectively. Cumulative distribution analysis curves were established. From these data, 3.3 ng/ml gave 96% specificity. Using this cutoff, the sensitivity for small cell lung cancer was 16% (n = 74) compared to 41% for NSCLC (n = 547). In histological sub-groups, sensitivity was 57% for squamous cell lung cancer, 34% for undifferentiated large cell carcinoma and 27% for adenocarcinoma, the level of CYFRA 21-1 was correlated with tumour size and UICC stage. In squamous cell lung cancer, the sensitivity of the squamous cell carcinoma marker was 30%, 25% for carcinoembryonic antigen and 46% for tissue polypeptide antigen, using the same series of samples and cutoffs defined at 96% specificity. In conclusion, CYFRA 21-1 is a sensitive tumour marker for NSCLC, especially squamous cell lung cancer.

Adolescent↗
PubMed1994

Relationship of PS2 with response to tamoxifen therapy in patients with recurrent breast cancer.

PS2, an oestrogen-inducible protein, was measured in the cytosol of 230 primary tumours from patients who were subjected to first-line tamoxifen therapy for advanced disease without prior adjuvant therapy with tamoxifen. PS2 correlated positively with oestrogen receptor (ER, P < 0.01) and progesterone receptor content (PgR, P < 0.001), and with the length of progression-free survival (PFS, P = 0.05). Although not statistically significant, higher levels of PS2 (> or = 10 ng mg-1 protein) were also associated with increased probability of response to tamoxifen treatment and a longer total post-relapse survival (PRS). ER, PgR, menopausal status, site of disease and prior adjuvant chemotherapy were all associated with response to tamoxifen therapy and with PFS. In multivariate analysis for PFS, low levels of ER and PgR, visceral metastasis, a disease-free interval of less than 1 year and prior adjuvant chemotherapy were all significantly associated with an increased probability of a rapid disease progression after start of tamoxifen therapy. In the subset of 83 tumours with intermediate levels of ER and PgR (both > or = 10, but not both > or = 75 fmol mg-1 protein), PS2 was positively related with the length of PFS (P < 0.01) and PRS (P < 0.05). PS2 remained the strongest factor in multivariate analysis for PFS (P < 0.01) in this ER/PgR intermediate subgroup, but was not of predictive value in univariate or multivariate analysis for both PFS and PRS in tumours classified as ER/PgR low or high (> or = 75 fmol mg-1 protein). It is concluded that PS2 status may be used as a parameter, additional to ER and PgR, for better refinement of prediction of response to tamoxifen treatment in advanced breast cancer patients especially with intermediate ER/PgR levels in their primary tumour.

Adult↗
PubMed1993

Prognostic value of PS2 and cathepsin D in 710 human primary breast tumors: multivariate analysis.

PURPOSE: Evaluation of the prognostic value of cytosolic PS2 (pS2 protein) and cathepsin D in a large series of breast cancer patients by multivariate analysis taking into account steroid receptors and conventional prognostic factors. PATIENTS AND METHODS: Prognostic factors were analyzed in 710 primary breast cancers (median follow-up, 4 years). PS2 and cathepsin D were measured by radiometric immunoassays. Estrogen receptor (ER) and progesterone receptor (PgR) status were assessed by radioligand binding assays and multiple-point Scatchard analysis. RESULTS: The best cutoff point for PS2 to discriminate between positive (61% of the tumors) and negative was 2 ng/mg protein (univariate P value in 5-year relapse-free survival = .003). For cathepsin D, no sensible cutoff point could be chosen, since there was a continuous association between the level of cathepsin D and relapse rate (P = .001). In Cox multivariate analysis, relapse rate decreased with age of premenopausal/perimenopausal patients and with PS2 or steroid receptor positivity, and increased with the size of the tumor, the number of positive lymph nodes, and increasing levels of cathepsin D. In analysis for overall survival, age of both premenopausal/perimenopausal and postmenopausal patients, tumor size, the number of positive lymph nodes, ER/PgR, and PS2 were all independently associated with the rate of death. The level of cathepsin D was positively correlated with the rate of death, but this trend was not statistically significant. Separate Cox multivariate analyses for relapse-free survival in subgroups of patients as defined by nodal status showed that the contribution of PS2 and cathepsin D was the strongest in the node-negative subgroup. Node-negative patients with tumors containing PS2 values < or = 2 ng/mg protein and cathepsin D values more than 70 pmol/mg protein experienced a 4.5-fold increase in relapse rate as compared with those with PS2 levels greater than 2 ng/mg protein and cathepsin D levels < or = 30 pmol/mg protein. CONCLUSION: PS2 and cathepsin D are independent prognostic factors in primary breast cancer and lymph node-negative patients.

Adult↗