Vasectomy by ligation and excision, with or without fascial interposition: a randomized controlled trial [ISRCTN77781689]

BACKGROUND: Randomized controlled trials comparing different vasectomy occlusion techniques are lacking. Thus, this multicenter randomized trial was conducted to compare the probability of the success of ligation and excision vasectomy with, versus without, fascial interposition (i.e. placing a layer of the vas sheath between two cut ends of the vas). METHODS: The trial was conducted between December 1999 and June 2002 with a single planned interim analysis. Men requesting vasectomies at eight outpatient clinics in seven countries in North America, Latin America, and Asia were included in the study. The men were randomized to receive vasectomy with versus without fascial interposition. All surgeons performed the vasectomies using the no-scalpel approach to the vas. Participants had a semen analysis two weeks after vasectomy and then every four weeks up to 34 weeks. The primary outcome measure was time to azoospermia. Additional outcome measures were time to severe oligozoospermia (<100 000 sperm/mL) and vasectomy failure based on semen analyses. RESULTS: We halted recruitment after the planned interim analysis, when 841 men had been enrolled. Fascial interposition decreased time to azoospermia (hazard ratio [HR], 1.35; P < 0.0001) and time to severe oligozoospermia (HR, 1.32; P < 0.0001) and reduced failures based on semen analysis by about half, from 12.7% (95% confidence interval [CI], 9.7 to 16.3) to 5.9% (95% CI, 3.8 to 8.6) (P < 0.0001). Older men benefited less from fascial interposition than younger men in terms of the speed of achieving azoospermia. However, the number of vasectomy failures was reduced to a similar degree in all age groups. Slightly more adverse events occurred in the fascial interposition group, but the difference was not significant. These failure rates may appear high to practitioners in countries such as the USA, but they are similar to results from other careful studies of ligation and excision techniques. CONCLUSION: Fascial interposition significantly improves vasectomy success when ligation and excision is the method of vas occlusion. A limitation of this study is that the correlation between postvasectomy sperm concentrations and risk of pregnancy is not well quantified

Methodologies used to estimate tobacco-attributable mortality: a review

<p>Abstract</p> <p>Background</p> <p>One of the most important measures for ascertaining the impact of tobacco on a population is the estimation of the mortality attributable to its use. To measure this, a number of indirect methods of quantification are available, yet there is no consensus as to which furnishes the best information. This study sought to provide a critical overview of the different methods of attribution of mortality due to tobacco consumption.</p> <p>Method</p> <p>A search was made in the Medline database until March 2005 in order to obtain papers that addressed the methodology employed for attributing mortality to tobacco use.</p> <p>Results</p> <p>Of the total of 7 methods obtained, the most widely used were the prevalence methods, followed by the approach proposed by Peto et al, with the remainder being used in a minority of studies.</p> <p>Conclusion</p> <p>Different methodologies are used to estimate tobacco attributable mortality, but their methodological foundations are quite similar in all. Mainly, they are based on the calculation of proportional attributable fractions. All methods show limitations of one type or another, sometimes common to all methods and sometimes specific.</p

New contraceptive eligibility checklists for provision of combined oral contraceptives and depot-medroxyprogesterone acetate in community-based programmes.

Community-based services (CBS) have long used checklists to determine eligibility for contraceptive method use, in particular for combined oral contraceptives (COCs) and the 3-month injectable contraceptive depot-medroxyprogesterone acetate (DMPA). As safety information changes, however, checklists can quickly become outdated. Inconsistent checklists and eligibility criteria often cause uneven access to contraceptives. In 1996, WHO produced updated eligibility criteria for the use of all contraceptive methods. Based on these criteria, new checklists for COCs and DMPA were developed. This article describes the new checklists and their development. Several rounds of expert review produced checklists that were correct, comprehensible and consistent with the eligibility requirements. Nevertheless, field-testing of the checklists revealed that approximately half (48%) of the respondents felt that one or more questions still needed greater comprehensibility. These findings indicated the need for a checklist guide. In March 2000, WHO convened a meeting of experts to review the medical eligibility criteria for contraceptive use. The article reflects also the resulting updated checklist