Severity of Clostridium difficile-associated diarrhea in solid organ transplant patients.

Clostridium difficile-associated diarrhea (CDAD) has a wide spectrum of disease severity. Studies have implicated immunosuppressants as a risk factor for severe disease. We hypothesized that solid organ transplant (SOT) patients with CDAD would be at greater risk for severe disease because of their profound immunosuppression. Adult SOT patients with CDAD seen at Duke University Medical Center between 1999 and 2003 were compared with a reference group of non-transplant patients with CDAD. The primary outcome was the development of complicated colitis defined as death, intensive care unit admission, or urgent colectomy within 30 days of diagnosis. A secondary outcome was relapse within 60 days. Eighty transplant and 86 non-transplant cases were reviewed. There was no significant difference in the development of complicated colitis (13.8% vs. 7.0%) or relapse rates (6.2% vs. 7.0%) between the 2 groups. In the entire sample, 18.5% of patients receiving corticosteroids unrelated to transplantation relapsed as compared with 4.5% not receiving corticosteroids (risk ratio 4.3, P=0.02). In conclusion, no significant difference was found in severity of CDAD between SOT patients and non-transplant patients. Exposure to corticosteroids was significantly associated with an increased risk of relapse and may warrant a longer treatment course.

Monograph support provided by the National Library of Medicine and its regional medical libraries in the medical behavioral sciences.

The National Library of Medicine's (NLM) monographic resources in the medical behavioral sciences (MBS) were examined to assess NLM's ability to support the needs of researchers writing in this area. A sample of 239 representative monographs derived from citations in MBS-related articles published in 61 journals in 1981 were evaluated. These monographs were limited to works published between 1978 and 1981, inclusive. The subject distribution of the sample included fourteen of the twenty-one main classes in the LC classification, although BF (psychology), H (social sciences), and R (medicine) constituted 80.3% of the sample. The study revealed that NLM held 48.5% of the sample. The holdings of ten research medical libraries, including six of the seven regional medical libraries, were also evaluated in order to gauge NLM's ability to support that element of the medical library network. The holding rates of these libraries ranged widely (9.6% to 36%), although NLM was found to have far more extensive holdings overall, and when assessed against classes BF, H, and R. Overall, NLM could have supplied from 28.8% to 44.5% of the monographs not held by the medical libraries. In only a few cases were the ten medical libraries able to provide access to monographs not held by NLM. The findings of the study indicate that, regardless of NLM's indication of support to the MBS area, the holdings of more general research and academic libraries are essential to support the monograph needs of MBS researchers.

Tests of methods for evaluating bibliographic databases: an analysis of the National Library of Medicine's handling of literatures in the medical behavioral sciences.

This article reports on five separate studies designed for the National Library of Medicine (NLM) to develop and test methodologies for evaluating the products of large databases. The methodologies were tested on literatures of the medical behavioral sciences (MBS). One of these studies examined how well NLM covered MBS monographic literature using CATLINE and OCLC. Another examined MBS journal and serial literature coverage in MEDLINE and other MBS-related databases available through DIALOG. These two studies used 1010 items derived from the reference lists of sixty-one journals, and tested for gaps and overlaps in coverage in the various databases. A third study examined the quality of the indexing NLM provides to MBS literatures and developed a measure of indexing as a system component. The final two studies explored how well MEDLINE retrieved documents on topics submitted by MBS professionals and how online searchers viewed MEDLINE (and other systems and databases) in handling MBS topics. The five studies yielded both broad research outcomes and specific recommendations to NLM.

Informal contacts in science: a probabilistic model for communication processes.

Significant contacts among scientists within research specialties are generally infrequent and are distributed as an essentially random process, the pattern of most contacts conforming to a Poisson distribution. Extremely productive persons in a specialty, however, seem to form a separate distribution; they have a considerably higher number of contacts.