Impact of severity of illness bias and control group misclassification bias in case-control studies of antimicrobial-resistant organisms.

BACKGROUND: Case-control studies often analyze risk factors for antibiotic resistance. Recently published articles have illustrated that randomly selected control-patients may be preferable to those with the susceptible phenotype of the organism. A possible methodologic problem with randomly selected control-patients is potential bias due to control group misclassification. This occurs if some control-patients did not have clinical cultures performed and thus might have been unidentified case-patients. If this bias exists, these studies might be expected to report lower odds ratios (ORs) because control-patients would be more like case-patients. OBJECTIVE: To analyze potential biases that might arise due to control group misclassification and potentially larger selection biases that may be introduced if control-patients are required to have at least one clinical culture. PATIENTS: One hundred twenty case-patients, 770 control-patients in group 1, and 510 control-patients in group 2. METHODS: Two case-control studies. Case-patients had clinical cultures positive for imipenem-resistant Pseudomonas aeruginosa. The first group of control-patients were random. The second group of control-patients were identical to those in group 1 except being required to have at least one clinical culture. RESULTS: Univariate analyses showed higher ORs for case-patients versus control-patients in group 1 (imipenem [OR, 12.5], piperacillin-tazobactam [OR, 3.7], and vancomycin [OR, 4.7]) as compared with case-patients versus control-patients in group 2 (imipenem [OR, 8.0], piperacillin-tazobactam [OR, 2.5], and vancomycin [OR, 3.0]). CONCLUSION: Requiring control-patients to have at least one clinical culture introduces a selection bias likely because it eliminates patients with less severe illness.     

The case-case-control study design: addressing the limitations of risk factor studies for antimicrobial resistance.

OBJECTIVE: There are significant limitations of the standard case-control study design for identifying risk factors for resistant organisms. The objective of this study was to develop a study design to overcome these limitations. DESIGN: Theoretical analysis of different types of study designs that can be used in risk factor studies for resistant organisms. RESULTS: We developed the case-case-control study design, which uses two separate case-control analyses within a single study. The first analysis compares patients infected with resistant bacteria (resistant cases) with control-patients without infection caused by the target organism, who are therefore representative of the source population; and the second analysis compares patients infected with the susceptible phenotype of the target organism (susceptible cases) with the same control-patients without infection caused by the target organism. These two analyses provide risk models for (1) isolation of the resistant phenotype of the target organism as compared with the source population and (2) isolation of the susceptible phenotype of the organism as compared with the source population. When these two risk models are compared and contrasted, risk factors specifically associated with isolation of the resistant phenotype can be identified. CONCLUSIONS: The case-case-control study design is an effective method for identifying risk factors for antimicrobial-resistant pathogens. Although the case-case-control study design has limitations, it is, in our opinion, more informative and less flawed than the standard case-control study design.     

Randomized trial of two intravenous schedules of the topoisomerase I inhibitor liposomal lurtotecan in women with relapsed epithelial ovarian cancer: a trial of the national cancer institute of Canada clinical trials group.

PURPOSE: Liposomal lurtotecan (OSI-211) is a liposomal formulation of the water-soluble topoisomerase I inhibitor lurtotecan (GI147211), which demonstrated superior levels of activity compared with topotecan in preclinical models. We studied two schedules of OSI-211 in a randomized design in relapsed ovarian cancer to identify the more promising of the two schedules for further study. PATIENTS AND METHODS: Eligible patients had measurable epithelial ovarian, fallopian, or primary peritoneal cancer that was recurrent after one or two prior regimens of chemotherapy. Patients were randomly assigned to receive either arm A (OSI-211 1.8 mg/m(2)/d administered by 30-minute intravenous infusion on days 1, 2, and 3 every 3 weeks) or arm B (OSI-211 2.4 mg/m(2)/d administered by 30-minute intravenous infusion on days 1 and 8 every 3 weeks). The primary outcome measure was objective response, which was confirmed by independent radiologic review, and a pick the winner statistical design was used to identify the schedule most likely to be superior. RESULTS: Eighty-one patients were randomized between October 2000 and September 2001. The hematologic toxic effects were greater on arm A than on arm B (grade 4 neutropenia, 51% v 22%, respectively), as was febrile neutropenia (26% v 2.4%, respectively). Of the 80 eligible patients, eight patients (10%) had objective responses; six responders (15.4%; 95% CI, 6% to 30%) were in arm A and two responders (4.9%; 95% CI, 1% to 17%) were in arm B. CONCLUSION: The OSI-211 daily for 3 days intravenous schedule met the statistical criteria to be declared the winner in terms of objective response. This schedule was also associated with more myelosuppression than the schedule of OSI-211 administered in arm B.     

Multi-impulsivity among bulimic patients in Japan

OBJECTIVE: Studies in Western world patients suggest the possible existence of a subgroup of patients with bulimia nervosa (BN) who display multiple problems with impulsivity, such as suicidal attempts. We assessed impulsive behaviors among BN patients in Japan to discuss them crossculturally. METHOD: Impulsive behaviors in 64 BN patients were assessed and multi-impulsivity (MI) was defined according to the definition proposed by Fichter, Quadflieg, and Rief (Psychological Medicine, 24, 591-604,1994). RESULTS: Nineteen patients (30%) met the definition of MI. BN patients with MI had more severe clinical features, such as concurrent depressive and anxious symptoms, global functioning, and higher prevalence of borderline personality disorder than BN patients without MI. DISCUSSION: These results showed the similarities between BN patients with MI in Japan and those patients in the Western world in clinical and psychopathological characteristics and a life-time incidence of each impulsive behavior. These findings may suggest culturally free bases for linkage between BN and MI.     

前列腺癌近距离放疗41例疗效回顾

目的 :观察早期局限性前列腺癌12 5I近距离放疗的临床效果。　方法 :对 4 1例确诊的局限性前列腺癌患者进行前列腺内12 5I植入。采用两步法 ,即治疗前进行前列腺体积研究 ,确定前列腺各部位放射量 ,处方剂量 16 0Gy;治疗中直肠超声波探头和C臂X线协助定位 ,专职护士长期随访。　结果 :获得长期随访 (3～ 4年 ) 33例(80 % ) ,其中 2例 (6 % )前列腺特异抗原 (PSA)升高者经穿刺确诊肿瘤局部复发 ,无死亡病例。早期并发症主要为尿路刺激症状 ,6个月内症状严重 ,1年以后症状消失。　结论 :前列腺近距离放疗生存率高 ,有短期尿路刺激症状 ,长期并发症少。     

Die vierte Naht im MACS-Lift

The main drawback of the classic MACS-lift is the poor lifting effect in the medial neck and submandibular area, which results in a suboptimal aesthetic outcome in cases of severe excesses of neck skin, as well as poor outcome in cases of severe platysmal banding. To overcome these limitations, we describe a modification of the original technique, which maximizes the rejuvenation effect on the neck while keeping the proven advantage of short and less visible scars. Modifying the technique by introducing a 4^th SMAS suture to perform lateral platysma plication through a caudally extended dissection 3?C4?cm below the mandibular arch/jaw line creates a more accentuated submandibular angle resulting in a sharper, more defined jaw line. Combined with extensive submandibular liposuction/lipectomy and in some cases closed platysma myotomy, this technique creates a concave submandibular space which enables redraping of a large volume of midneck skin, often eliminating the need for additional posterior or anterior cervicoplasty (??convex becomes concave??).     

The role of ambiguity in sexual encounters between young people in England

This paper explores the role of ambiguity in sexual encounters between young people. It is based on a qualitative study of young peoples' communication about sexual matters whilst on a date. Focus groups (4) and semi-structured interviews ( n = 29) were conducted with young people (aged 16-29) in three areas of England. The results suggest that ambiguity may serve a useful function in the management of ambivalence during sexual encounters; may protect the self and others from the pain of rejection; and may guard against the possibility of making a false assumption. In such contexts, ambiguity may constitute a reasoned or rational response to a given set of circumstances. This rationality needs to be acknowledged by health professionals. Ambiguity is also sometimes construed as an appropriate mode of communication for a passive female role. Given the complex motivations behind the adoption of ambiguous cues, discussion-based teaching and peer group formats may be more appropriate than didactic teaching methods when helping young people to adopt more direct communication strategies.