Healthcare interventions for consumers/public
The Cochrane Collaboration, is a not for profit organisation which produces systematic reviews on the effects of healthcare interventions. These reviews are published in an online database, The Cochrane Library monthly.
What is a systematic review?
A systematic review asks a specific research question about a particular healthcare intervention in a clearly defined group of people with a health condition or problem. These reviews summarise the results of healthcare studies and provides the evidence on the effectiveness of the interventions. Systematic reviews are complex and depend on what clinical trials have been conducted, the quality of the trials and the health outcomes that were measured. The review authors combine the numerical data about the effects of the treatment and the authors assess the benefits and harms for the specific treatment.1
For more information about what consumers can and cannot get from systematic reviews, please visit the Cochrane Consumer website.
The South African Cochrane Centre which is part of the Cochrane Collaboration, will publish consumer summaries monthly as listed below. Should you require information for a specific health condition please go to http://summaries.cochrane.org/ and search for the information you require or alternatively contact email@example.com
1. Cochrane Consumer Network (www.consumers.cochrane.org). Accessed 17 August 2012
Oral evening primrose oil and borage oil for eczema
Eczema is an itchy and red skin condition, which may affect 20% of people world wide at some time in their life. Though it may improve with age, there is no cure. Many children outgrow this disorder as they reach secondary school age. Constant itch makes life uncomfortable for those with this condition, no matter what age they are.
Conventional medical treatments make life better for people; however, some people who do not see an adequate improvement in their eczema or fear side-effects of conventional medical products, turn to complementary alternatives to conventional medical treatment. This review is of two such products: evening primrose oil (EPO) and borage oil (BO) taken orally (by mouth), which have been thought to have benefits for eczema.
We included 27 studies, with 1596 adults and children from 12 countries. Of these, 19 studies compared EPO with a placebo (dummy) treatment, and 8 used BO compared with placebo. We looked for evidence of overall improvement in eczema and in quality of life. All 27 studies evaluated overall improvement of eczema, but only 2 studies of EPO measured improvement in quality of life. There was no statistically significant advantage demonstrated for either EPO or BO compared to placebo. In summary, we did not find evidence that eczema improved by taking these products any more than it did by taking placebo.
There was some evidence of mild and temporary side-effects for participants with either product or placebo, which were mainly mild, and included temporary headache and upset stomach or diarrhoea. With EPO there is an anticoagulant (blood-thinning) effect when taking these products. There is a warning with the blood thinner warfarin (Coumadin®) that taking EPO can increase bleeding. One report warns that if EPO is taken for a prolonged period of time (more than one year), there is a potential risk of inflammation, thrombosis, and immunosuppression due to slow accumulation of EPO in the tissues. Another reports a single case in which EPO was thought to have produced harms. We found no clinical evidence of such harm in these short-term trials.
This systematic review found no evidence that either BO or EPO are effective in treatment of eczema. Both of these products and the placebos used in the studies had similar mild, temporary side-effects, which were mainly gastrointestinal.
Citation: Bamford JTM, Ray S, Musekiwa A, van Gool C, Humphreys R, Ernst E. Oral evening primrose oil and borage oil for eczema. Cochrane Database of Systematic Reviews 2013, Issue 4. Art. No.: CD004416. DOI: 10.1002/14651858.CD004416.pub2
Mammography followed by ultrasonography compared to mammography alone for breast cancer screening in women at average risk of breast cancer
Worldwide, breast cancer is the most common malignancy in women. Evidence shows that mammography in healthy women 50 to 70 years of age can detect breast cancer early and reduce the risk of dying from breast cancer. Mammography, however, is not a perfect tool to detect breast cancer and misses some tumours in some women, particularly in women who have dense breasts. In women with dense breasts, the normal breast tissue and the tumour are difficult to distinguish from each other on the mammogram. Because of this, some supporters feel that the addition of ultrasonography screening of these women in addition to the mammography screening will detect those tumours that are missed by mammography alone. Others feel that this will increase the rate of false positive tumours and increase the number of biopsies and unnecessary treatment.
The benefit of ultrasound as an additional examination for women who do not have especially dense breasts and who have normal mammographies is uncertain. This review sought to examine the evidence for and against adding ultrasonography screening to mammograms for women at average risk for breast cancer. It is important to weigh positive and negative sides of screening because the detection of more tumours by screening does not necessarily mean that more women will have their lives saved. We need to assess whether the few additional cancers that may be detected by ultrasonography lead to a real decrease in mortality from breast cancer and then balance any benefit against the harm caused by many women being incorrectly alarmed or diagnosed.
We did not find any trials that addressed our review question. One randomised controlled trial is currently underway in Japan (called J-START). Because it is unclear whether ultrasonography in women with normal mammographies can reduce the risk of dying from breast cancer, they should not be used on a routine basis. If screening with ultrasonography is performed it should be as part of a clinical trial designed to test the effect of additional screening on mortality and the harms experienced by women who have a positive ultrasonography screening test.
Citation: Gartlehner G, Thaler K, Chapman A, Kaminski-Hartenthaler A, Berzaczy D, Van Noord MG, Helbich TH. Mammography in combination with breast ultrasonography versus mammography for breast cancer screening in women at average risk. Cochrane Database of Systematic Reviews 2013, Issue 4. Art. No.: CD009632. DOI: 10.1002/14651858.CD009632.pub2.
Antiretroviral therapy for prevention of HIV transmission in HIV-discordant couples
Antiretroviral drugs can prevent transmission of HIV from an infected sexual partner to an uninfected one, by suppressing viral replication. We found one randomised controlled trial and nine observational studies that examined this question. Overall we found that in couples in which the infected partner was being treated with antiretroviral drugs the uninfected partners had, at worst, more than 40% lower risk of being infected than in couples where the infected partner was not receiving treatment. Since the World Health Organization (WHO) already recommends antiretroviral treatment for all persons with ≤350 CD4 cells/µL, we also examined studies that had studied couples in which the infected partners had CD4 counts higher than this level. We found that there is strong evidence from the randomised controlled trial that in this group HIV was less likely to be transmitted to uninfected partners from treated infected partners than from untreated infected partners.
Citation: Anglemyer A, Rutherford GW, Horvath T, Baggaley RC, Egger M, Siegfried N. Antiretroviral therapy for prevention of HIV transmission in HIV-discordant couples. Cochrane Database of Systematic Reviews 2013, Issue 4. Art. No.: CD009153. DOI: 10.1002/14651858.CD009153.pub3
Hormone therapy for preventing cardiovascular disease in both healthy post-menopausal women and those with pre-existing cardiovascular disease
Hormone therapy (HT) is used for controlling menopausal symptoms. It has also been used for the management and prevention of cardiovascular disease (CVD) in older post-menopausal women. The present review assessed the clinical effects of using HT for six-months or more. Thirteen randomised controlled trials (involving 38171 women aged 42 - 91) compared oral HT (oestrogen, with or without progestogen) with placebo. Most participants were post-menopausal American women, and the mean age in most studies was over 60 years. The length of time women were on treatment varied across the trials from 11.9 months to 7.1 years.
Overall, results showed no evidence that HT provides any protective effects against the development of CVD, either in healthy women or women with pre-existing heart disease. Rather, in relatively healthy post-menopausal women both single (oestrogen alone) and combination HT (oestrogen plus progestogen) significantly increased the risk of stroke and obstruction of a vein by a blood clot (venous thrombo-embolism). Combination HT, additionally, significantly increased the risk of suffering from a non-fatal heart attack or blood clots on the lungs (pulmonary embolism). Among women with existing CVD, combination HT significantly increased the risk of both venous thrombo-embolism and pulmonary embolism, but not stroke.
Citation: Main C, Knight B, Moxham T, Gabriel Sanchez R, Sanchez Gomez LM, Roqué i Figuls M, Bonfill Cosp X. Hormone therapy for preventing cardiovascular disease in post-menopausal women. Cochrane Database of Systematic Reviews 2013, Issue 4. Art. No.: CD002229. DOI: 10.1002/14651858.CD002229.pub3
|For more information, contact the South African Cochrane Centre on (021) 938 0834 or email Joy.Oliver@mrc.ac.za.