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BACKGROUND Stepped wedge randomised trial designs involve sequential roll-out of an intervention to participants (individuals or clusters) over a number of time periods. By the end of the study, all participants will have received the intervention, although the order in which participants receive the intervention is determined at random. The design is(More)
BACKGROUND A possible therapeutic effect of diagnostic tubal patency testing has been debated in the literature for half a century. Further debate surrounds whether oil-soluble or water-soluble contrast media might have the bigger fertility-enhancing effect. OBJECTIVES To evaluate the effect of flushing a woman's fallopian tubes with oil- or water-soluble(More)
Surgery and other invasive therapies are complex interventions, the assessment of which is challenged by factors that depend on operator, team, and setting, such as learning curves, quality variations, and perception of equipoise. We propose recommendations for the assessment of surgery based on a five-stage description of the surgical development process.(More)
BACKGROUND Cluster randomised controlled trials (CRCTs) are frequently used in health service evaluation. Assuming an average cluster size, required sample sizes are readily computed for both binary and continuous outcomes, by estimating a design effect or inflation factor. However, where the number of clusters are fixed in advance, but where it is possible(More)
The history of monitoring the outcomes of health care by external agencies can be traced to ancient times. However, the danger, now as then, is that in the search for improvement, comparative measures of mortality and morbidity are often overinterpreted, resulting in judgments about the underlying quality of care. Such judgments can translate into(More)
OBJECTIVE To compare the effects of laparoscopic hysterectomy and abdominal hysterectomy in the abdominal trial, and laparoscopic hysterectomy and vaginal hysterectomy in the vaginal trial. DESIGN Two parallel, multicentre, randomised trials. SETTING 28 UK centres and two South African centres. PARTICIPANTS 1380 women were recruited; 1346 had surgery;(More)
BACKGROUND Problems in inducing ovulation in women with polycystic ovary syndrome (PCOS) and anovulation (failure to ovulate) are well recognised. Surgical ovarian wedge resection was the first established treatment for anovulatory PCOS patients but was largely abandoned due to the risk of post-surgical adhesions and the introduction of medical ovulation(More)
OBJECTIVE To compare maternal mortalities attributable to vaginal delivery, elective caesarean section (CS) and intrapartum CS. DESIGN The number of deaths associated with each method of delivery was ascertained among unselected and among low-risk women by detailed retrospective review of the case-notes of women who died after delivery. The frequency of(More)
Fifteen patients with various developmental and acquired abnormalities of the vagina were treated by the application of human amnion over a mold after surgical dissection of a space for the new vagina or enlargement of an existing but strictured one. Excellent results were achieved in cases of complete and partial vaginal agenesis, and there was improvement(More)
This is the second in a four-part series of articles detailing the epistemology of patient safety research. This article concentrates on issues of study design. It first considers the range of designs that may be used in the evaluation of patient safety interventions, highlighting the circumstances in which each is appropriate. The paper then provides(More)