Infertility Treatments for Women A Review of the Bio-medical ...

More documents

Recommendations

Info

The Women’s Health Council researchers know which group the participants were allocated to. A “placebo-controlled” trial includes a control group of participants who were given a placebo (“dummy pill or treatment”) designed to appear the same, but have no physiological effect (Bowling, 2000). Sometimes an improvement is seen in participants receiving a placebo treatment. This is known as the “placebo affect”, a known phenomenon, where by study participants receiving a placebo still show a clinical improvement, because of a belief that they are being given a drug treatment. When this is evident in the treatment group, it means that the treatment is no more affective than the placebo. The methodological factors described above aim to reduce the risk of bias and improve the quality of the research. RCTs, if well conducted, can indicate what treatment is better, although they often cannot identify for whom it is better. This is because RCTs are often carried out on specific types of patients for a relatively short period of time, whereas in practice the treatment would be carried out on a much greater variety of patients. Observational studies are studies where the subjects are observed in their natural state. Observational studies include cohort studies, case-control studies and cross-sectional surveys. These studies are generally more prone to bias and therefore provide weaker evidence on the effectiveness of interventions compared with RCTs (Guyatt et al., 1995). Literature reviews, if well conducted, can provide a good summary of evidence. Systematic reviews differ from traditional literature reviews as they use a replicable, scientific and transparent approach that seeks to minimise bias (NHS CRD, 2001). Cochrane systematic reviews, produced by The Cochrane Collaboration (The Cochrane Collaboration, 2005), generally focus on evidence from RCTs because of the common acceptance that RCTs will lead to the most reliable estimates of effectiveness (Higgins & Green, 2006). Cochrane reviews are therefore considered to be very good quality reviews. Finally, a meta-analysis is a study that uses statistical methods to combine the findings from several studies which all address the same question. A hierarchy of study designs is shown in Figure 1. 24
Infertility Treatments for Women A Review of the Bio-medical Evidence Figure 1: Hierarchy of study design Less risk of bias Study Design Literature reviews Meta-analysis Cochrane systematic reviews Systematic reviews Experimental studies Randomised controlled trials Observational studies Cohort studies Case-control studies Cross-sectional surveys Case reports (Adapted from: Guyatt et al., 1995) In this review good quality evidence from guidelines relating to the menopause were initially sought. Evidence from Cochrane reviews, other systematic reviews, and RCTs was also sought. Where evidence was extremely limited or unavailable from these sources, evidence from observational studies was sought. 3.4 Reporting of infertility treatment outcomes The most relevant outcome to couples is live birth rate. As this outcome adds to the time and effort required in order to collect such data, studies may report other outcomes such as ongoing pregnancy rate instead. The definition of ongoing pregnancy rate is often not consistent between studies, but in general is it used to describe a pregnancy that is less likely to miscarry (Daya, 2003). From a clinical perspective the clinical pregnancy rate is the most important outcome to consider. The clinical pregnancy rate is defined as a pregnancy where a foetal heartbeat is detected with an ultrasound. Outcomes such as ovarian hyperstimulation syndrome (OHSS) [see section 7.9.2], ectopic pregnancies, fetal abnormalities, or miscarriage are important to examine when looking at treatment effectiveness. Multiple births are considered an undesirable consequence of fertility treatment, and therefore the multiple birth rates, or singleton live birth rates are important outcomes to examine (Daya, 2003). Other outcomes of importance are cycle cancellation, low birth weight and perinatal mortality (NCC WCH, 2004). 25
Page 1 and 2: Infertility Treatments for Women A
Page 25: Infertility Treatments for Women A
Page 77 and 78:
Infertility Treatments for Women A
Page 79 and 80:
Page 81 and 82:
Page 83 and 84:
Page 85 and 86:
Page 87 and 88:
Page 89 and 90:
Page 91 and 92:
Page 93 and 94:
Page 95 and 96:
Page 97 and 98:
Page 99 and 100:
Page 101 and 102:
Page 103 and 104:
Page 105 and 106:
Page 107 and 108:
Page 109 and 110:
Page 111 and 112:
Page 113 and 114:
Page 115 and 116:
Page 117 and 118:
Page 120:
The physical and psychological burd
show all

Infertility Treatments for Women A Review of the Bio-medical ...

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?