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  • 1
    Online Resource
    Online Resource
    SAGE Publications ; 2021
    In:  Statistical Methods in Medical Research Vol. 30, No. 2 ( 2021-02), p. 357-375
    In: Statistical Methods in Medical Research, SAGE Publications, Vol. 30, No. 2 ( 2021-02), p. 357-375
    Abstract: To estimate the mean of a quantitative variable in a hierarchical population, it is logistically convenient to sample in two stages (two-stage sampling), i.e. selecting first clusters, and then individuals from the sampled clusters. Allowing cluster size to vary in the population and to be related to the mean of the outcome variable of interest (informative cluster size), the following competing sampling designs are considered: sampling clusters with probability proportional to cluster size, and then the same number of individuals per cluster; drawing clusters with equal probability, and then the same percentage of individuals per cluster; and selecting clusters with equal probability, and then the same number of individuals per cluster. For each design, optimal sample sizes are derived under a budget constraint. The three optimal two-stage sampling designs are compared, in terms of efficiency, with each other and with simple random sampling of individuals. Sampling clusters with probability proportional to size is recommended. To overcome the dependency of the optimal design on unknown nuisance parameters, maximin designs are derived. The results are illustrated, assuming probability proportional to size sampling of clusters, with the planning of a hypothetical survey to compare adolescent alcohol consumption between France and Italy.
    Type of Medium: Online Resource
    ISSN: 0962-2802 , 1477-0334
    Language: English
    Publisher: SAGE Publications
    Publication Date: 2021
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  • 2
    In: Tumori Journal, SAGE Publications, Vol. 93, No. 5 ( 2007-09), p. 461-466
    Abstract: Occult/obscure gastrointestinal bleeding is often problematic to diagnose. It often leads to delayed treatment, a particularly dangerous circumstance when tumor origins are involved. This study reports the six-year experience of an Italian Surgery Center in the identification of the nature (tumor versus non tumor) and site of origin (upper, middle, lower gastrointestinal tract) of occult/obscure bleeding requiring hospitalization, as well as in its treatment. Methods Diagnostic instrumental examinations employed were: esophagogastroduodenoscopy, rectocolonoscopy, computerized tomography small bowel follow-through examination, capsule endoscopy, biopsy, angiography, abdominal computerized tomography scans and ultrasound. Therapies included: interventional radiology and surgery. Results Thirty-five cases of obscure and 27 cases of occult bleeding were examined; all received a definite diagnosis during hospitalization. In the cases with obscure bleeding the diagnosis was inflammatory bowel disease (n = 7), angiodysplasia (5 gastric, 2 duodenal, 2 jejunal, 3 ileal, 4 right colon), small bowel tumors (4 non-Hodgkin lymphomas, 1 leiomyoma, 6 adenocarcinomas), and gastric metaplasia of Meckel's diverticulum (n = 1). There were significantly more nontumor lesions than tumors (P 〈 0.005), and a middle tract source was significantly more frequent than upper/lower tract sources (P 〈 0.0001). Intestinal resections were performed for all small bowel tumors (8 laparotomic, 3 laparoscopic), 5 angiodysplasias, all cases of inflammatory bowel disease and gastric metaplasia of Meckel's diverticulum; arterial embolization was performed for 11 angiodysplasias. In the cases with occult bleeding the diagnosis was sigmoid colon polyps in 6 (treatment, endoscopic polypectomy) and right colon cancer in 21 (treatment, right hemicolectomy). There were significantly more tumors than nontumor lesions (P 〈 0.0001); all derived from the lower gastrointestinal tract. In all cases, the interventions resolved the bleeding completely. Conclusions The results show that more than 50% of cases with obscure/occult bleeding requiring hospitalization are motivated by malignant gastrointestinal tumors, 34% of which are located in the small bowel, usually a difficult tract to explore. Thanks to modern technology, however, their diagnosis and treatment can nowadays be promptly and successfully achieved.
    Type of Medium: Online Resource
    ISSN: 0300-8916 , 2038-2529
    Language: English
    Publisher: SAGE Publications
    Publication Date: 2007
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  • 3
    In: International Journal of Immunopathology and Pharmacology, SAGE Publications, Vol. 28, No. 3 ( 2015-09), p. 421-425
    Abstract: Few studies of long-term outcome of hypospadias treatment in terms of voiding, surgical complications, sexual functioning, intimate relationships and cosmetic results have been investigated and contrasting results have been obtained so far. The aim of our study is to investigate the long-term outcome of urinary and sexual function, cosmesis and the quality of intimate relationships in a series of hypospadias. In this study, 42 patients who underwent surgery for hypospadias were prospectively followed for 15 years. Medical records provided the hypospadias data, the number of reconstructive operations and the reconstruction technique that was used. Patients underwent physical examination, including penile length measurement and completed International Prostatic Symptoms Score (I-PSS), International Index Of Erectile Function (IIEF 15) and the Penile Perception Score questionnaire (PPPS). Twenty patients agreed to participate in the study. At the enrolment, the median value of HOSE was 13, as regards PPPS, 18/20 (90%) were satisfied, while in 1998 only 80% were satisfied. No significant statistical difference has been reported from the results obtained at enrolment and those obtained at follow-up, in terms of PPPS (P = 0.81), IPSS and IIEF-15. Penile length was 6.5 cm flaccid and 10.5 cm stretched. Our data show how cosmesis, function and psychosexual development for these patients are highly connected to surgical outcome, which is understood to be a decrease in penile size.
    Type of Medium: Online Resource
    ISSN: 0394-6320 , 2058-7384
    Language: English
    Publisher: SAGE Publications
    Publication Date: 2015
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  • 4
    In: Journal of Cerebral Blood Flow & Metabolism, SAGE Publications, Vol. 37, No. 9 ( 2017-09), p. 3253-3261
    Abstract: Inflammatory mediators and metalloproteinases are altered in acute ischemic stroke (AIS) and play a detrimental effect on clinical severity and hemorrhagic transformation of the ischemic brain lesion. Using data from the Italian multicenter observational MAGIC (MArker bioloGici nell’Ictus Cerebrale) Study, we evaluated the effect of inflammatory and metalloproteinases profiles on three-month functional outcome, hemorrhagic transformation and mortality in 327 patients with AIS treated with intravenous thrombolys in according to SITS-MOST (Safe Implementation of Thrombolysis in Stroke-MOnitoring STudy) criteria. Circulating biomarkers were assessed at baseline and 24 h after thrombolysis. Adjusting for age, sex, baseline glycemia and National Institute of Health Stroke Scale, history of atrial fibrillation or congestive heart failure, and of inflammatory diseases or infections, baseline alpha-2macroglobulin (A2M), baseline serum amyloid protein (SAP) and pre-post tissue-plasminogen activator (tPA) variations (Δ) of metalloproteinase 9, remained significantly and independently associated with three-month death [OR (95% CI):A2M:2.99 (1.19–7.53); SAP:5.46 (1.64–18.74); Δmetalloproteinase 9:1.60 (1.12–2.27)]. The addition of baseline A2M and Δmetalloproteinase 9 or baseline SAP and Δmetalloproteinase 9 (model-2 or model-3) to clinical variables (model-1) significantly improved the area under curve for prediction of death [model-2 with A2M: p = 0.0205; model-3 with SAP: p = 0.001] . In conclusion, among AIS patients treated with thrombolysis, circulating A2M, SAP and Δmetalloproteinase 9 are independent markers of poor outcome. These results may prompt controlled clinical research about agents antagonizing their effect.
    Type of Medium: Online Resource
    ISSN: 0271-678X , 1559-7016
    Language: English
    Publisher: SAGE Publications
    Publication Date: 2017
    detail.hit.zdb_id: 2039456-1
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