Cochrane Db Syst Rev
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Cochrane Db Syst Rev · Nov 2015
Review Meta AnalysisAndrogens (dehydroepiandrosterone or testosterone) for women undergoing assisted reproduction.
Infertility is a condition affecting 10% to 15% of couples of reproductive age. It is generally defined as "the failure to achieve a clinical pregnancy after 12 months or more of regular unprotected sexual intercourse". The treatment of infertility may involve manipulation of gametes or of the embryos themselves. These techniques are together known as assisted reproductive technology (ART). Practitioners are constantly seeking alternative or adjunct treatments, or both, in the hope that they may improve the outcome of assisted reproductive techniques. This Cochrane review focusses on the adjunct use of synthetic versions of two naturally-produced hormones, dehydroepiandrosterone (DHEA) and testosterone (T), in assisted reproduction.DHEA and its derivative testosterone are steroid hormones proposed to increase conception rates by positively affecting follicular response to gonadotrophin stimulation, leading to greater oocyte yields and, in turn, increased chance of pregnancy. ⋯ In women identified as poor responders undergoing ART, pre-treatment with DHEA or testosterone may be associated with improved live birth rates. The overall quality of the evidence is moderate. There is insufficient evidence to draw any conclusions about the safety of either androgen. Definitive conclusions regarding the clinical role of either androgen awaits evidence from further well-designed studies.
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Cochrane Db Syst Rev · Nov 2015
Review Meta AnalysisUse of biochemical tests of placental function for improving pregnancy outcome.
The placenta has an essential role in determining the outcome of pregnancy. Consequently, biochemical measurement of placentally-derived factors has been suggested as a means to improve fetal and maternal outcome of pregnancy. ⋯ There is insufficient evidence to support the use of biochemical tests of placental function to reduce perinatal mortality or increase identification of small-for-gestational-age infants. However, we were only able to include data from two studies that measured oestrogens and hPL. The quality of the evidence was low or very low.Two of the trials were performed in the 1970s on women with a variety of antenatal complications and this evidence cannot be generalised to women at low-risk of complications or groups of women with specific pregnancy complications (e.g. fetal growth restriction). Furthermore, outcomes described in the 1970s may not reflect what would be expected at present. For example, neonatal mortality rates have fallen substantially, such that an infant delivered at 28 weeks would have a greater chance of survival were those studies repeated; this may affect the primary outcome of the meta-analysis.With data from just two studies (740 women), this review is underpowered to detect a difference in the incidence of death of a baby or the frequency of a small-for-gestational-age infant as these have a background incidence of approximately 0.75% and 10% of pregnancies respectively. Similarly, this review is underpowered to detect differences between serious and/or rare adverse events such as severe neonatal morbidity. Two of the three included studies were quasi-randomised, with significant risk of bias from group allocation. Additionally, there may be performance bias as in one of the two studies contributing data, participants receiving standard care did not have venepuncture, so clinicians treating participants could identify which arm of the study they were in. Future studies should consider more robust randomisation methods and concealment of group allocation and should be adequately powered to detect differences in rare adverse events.The studies identified in this review examined two different analytes: oestrogens and hPL. There are many other placental products that could be employed as surrogates of placental function, including: placental growth factor (PlGF), human chorionic gonadotrophin (hCG), plasma protein A (PAPP-A), placental protein 13 (PP-13), pregnancy-specific glycoproteins and progesterone metabolites and further studies should be encouraged to investigate these other placental products. Future randomised controlled trials should test analytes identified as having the best predictive reliability for placental dysfunction leading to small-for-gestational-age infants and perinatal mortality.
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Cochrane Db Syst Rev · Nov 2015
Review Meta AnalysisMethylphenidate for children and adolescents with attention deficit hyperactivity disorder (ADHD).
Attention deficit hyperactivity disorder (ADHD) is one of the most commonly diagnosed and treated psychiatric disorders in childhood. Typically, children with ADHD find it difficult to pay attention, they are hyperactive and impulsive.Methylphenidate is the drug most often prescribed to treat children and adolescents with ADHD but, despite its widespread use, this is the first comprehensive systematic review of its benefits and harms. ⋯ The results of meta-analyses suggest that methylphenidate may improve teacher-reported ADHD symptoms, teacher-reported general behaviour, and parent-reported quality of life among children and adolescents diagnosed with ADHD. However, the low quality of the underpinning evidence means that we cannot be certain of the magnitude of the effects. Within the short follow-up periods typical of the included trials, there is some evidence that methylphenidate is associated with increased risk of non-serious adverse events, such as sleep problems and decreased appetite, but no evidence that it increases risk of serious adverse events.Better designed trials are needed to assess the benefits of methylphenidate. Given the frequency of non-serious adverse events associated with methylphenidate, the particular difficulties for blinding of participants and outcome assessors point to the advantage of large, 'nocebo tablet' controlled trials. These use a placebo-like substance that causes adverse events in the control arm that are comparable to those associated with methylphenidate. However, for ethical reasons, such trials should first be conducted with adults, who can give their informed consent.Future trials should publish depersonalised individual participant data and report all outcomes, including adverse events. This will enable researchers conducting systematic reviews to assess differences between intervention effects according to age, sex, comorbidity, type of ADHD and dose. Finally, the findings highlight the urgent need for large RCTs of non-pharmacological treatments.
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Cochrane Db Syst Rev · Nov 2015
Review Meta AnalysisFornix-based versus limbal-based conjunctival trabeculectomy flaps for glaucoma.
Glaucoma is one of the leading largely preventable causes of blindness in the world. It usually is addressed first medically with topical intraocular pressure-lowering drops or by laser trabeculoplasty. In cases where such treatment fails, glaucoma-filtering surgery is considered, most commonly trabeculectomy surgery with variations in technique, for example, the type of conjunctival flap (fornix- or limbal-based). In a fornix-based flap, the surgical wound is performed at the corneal limbus; while in a limbal-based flap, the incision is further away. Many studies in the literature compare fornix- and limbal-based trabeculectomy with respect to outcomes and complications. ⋯ The main result of this review was that there was uncertainty as to the difference between fornix- and limbal-based trabeculectomy surgeries due to the small number of events and confidence intervals that cross the null. This also applied to postoperative complications, but without any impact on long-term failure rate between the two surgical techniques.
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Cochrane Db Syst Rev · Nov 2015
Review Meta AnalysisThyroid surgery for Graves' disease and Graves' ophthalmopathy.
Graves' disease is an autoimmune disease caused by the production of auto-antibodies against the thyroid-stimulating hormone receptor, which stimulates follicular cell production of thyroid hormone. It is the commonest cause of hyperthyroidism and may cause considerable morbidity with increased risk of cardiovascular and respiratory adverse events. Five per cent of people with Graves' disease develop moderate to severe Graves' ophthalmopathy. Thyroid surgery for Graves' disease commonly falls into one of three categories: 1) total thyroidectomy, which aims to achieve complete macroscopic removal of thyroid tissue; 2) bilateral subtotal thyroidectomy, in which bilateral thyroid remnants are left; and 3) unilateral total and contralateral subtotal thyroidectomy, or the Dunhill procedure. Recent American Thyroid Association guidelines on treatment of Graves' hyperthyroidism emphasised the role of surgery as one of the first-line treatments. Total thyroidectomy removes target tissue for the thyroid-stimulating hormone receptor antibody. It controls hyperthyroidism at the cost of lifelong thyroxine replacement. Subtotal thyroidectomy leaves a thyroid remnant and may be less likely to lead to complications, however a higher rate of recurrent hyperthyroidism is expected and revision surgery would be challenging. The choice of the thyroidectomy technique is currently largely a matter of surgeon preference, and a systematic review of the evidence base is required to determine which option offers the best outcomes for patients. ⋯ Total thyroidectomy is more effective than subtotal thyroidectomy (both bilateral subtotal thyroidectomy and the Dunhill procedure) at preventing recurrent hyperthyroidism in Graves' disease. The type of surgery performed does not affect regression of Graves' ophthalmopathy. There was some evidence that total thyroidectomy compared with subtotal thyroidectomy conferred a greater risk of permanent hypocalcaemia/hypoparathyroidism, which however, was not seen in comparison with bilateral subtotal thyroidectomy. Permanent recurrent laryngeal nerve palsy did not seem to be affected by type of thyroidectomy. Health-related quality of life as a patient-important outcome measure should form a core determinant of any future trial on the effects of thyroid surgery for Graves' disease.