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 joy.oliver@mrc.ac.za

References

1. Cochrane Consumer Network (www.consumers.cochrane.org). Accessed 17 August 2012

December 2012

Is taking inhaled corticosteroids only when asthma symptoms get worse as safe and effective as taking inhaled corticosteroids every day?
Chronic asthma is a disease caused by underlying inflammation in the airways (the small tubes in the lungs) and asthma attacks occur when the airways contract making it difficult for the person to breath. In people with mild asthma, inhaled corticosteroids are often recommended to be taken every day to control the underlying inflammation. However, many people with asthma take inhaled corticosteroids only when symptoms appear. We wanted to look for the available evidence from randomised controlled trials comparing the use of inhaled corticosteroids everyday with use of these drugs only at the time of worsening of symptoms in children and adults with persistent asthma (six trials representing 1211 patients).

This review of randomised controlled trials found no significant difference in the number of asthma attacks of moderate severity between people taking inhaled corticosteroids every day and those taking them 'as needed'. However, there was not enough information to conclude to that the two approaches were equivalent. However, we found that people taking inhaled corticosteroids everyday had slightly better asthma control with better lung function, less use of reliever medication and more symptom-free days than those taking inhaled corticosteroids intermittently.

We also observed that compared to intermittent inhaled corticosteroids, children grew slightly less with daily inhaled budesonide and beclomethasone (inhaled corticosteroids are known to affect growth), underlying the importance of using the safest and lowest effective dose of inhaled corticosteroids. We did not observe any significant group difference in the rate of withdrawals or adverse effects. These results do not provide firm conclusions, although the improvement in asthma control, lung function and airway inflammation would provide slightly greater support for the use of inhaled corticosteroids every day as compared to taking them only when symptoms get worse. Physicians and patients are advised to weigh the risks and benefits of each treatment option carefully and monitor the response of individual patients to adjust therapy as needed.

Citation: Chauhan BF, Chartrand C, Ducharme FM. Intermittent versus daily inhaled corticosteroids for persistent asthma in children and adults. Cochrane Database of Systematic Reviews 2012, Issue 12. Art. No.: CD009611. DOI: 10.1002/14651858.CD009611.pub2

Effects and safety of preventive oral iron or iron + folic acid supplementation for women during pregnancy
During pregnancy, women need iron and folate to meet both their own needs and those of the developing baby. The concern is that if pregnant women become deficient in these nutrients they are unable to supply them in sufficient quantities to their baby. Low folate before conceiving increases the risk of the baby having neural tube defects. Low iron and folate levels in women can cause anaemia, which can make women tired, faint, and at increased risk of infection.

We included 60 randomised trials in the review with 43 trials involving more than 27,402 pregnant women contributing to the analyses. The use of iron or iron and folic acid supplements was associated with a reduced risk of anaemia and iron deficiency during pregnancy and of giving birth to low birthweight babies. Daily iron supplementation was, however, associated with the women having side effects such as constipation and other gastrointestinal effects including nausea, vomiting and diarrhoea and an increased risk of high haemoglobin (Hb) concentrations at term. This may be harmful to mothers and babies and is associated with late pregnancy hypertension, pre-eclampsia and pregnancy complications. There is no evidence that iron supplementation increases placental malaria.

Citation: Peña-Rosas JP, De-Regil LM, Dowswell T, Viteri FE. Daily oral iron supplementation during pregnancy. Cochrane Database of Systematic Reviews 2012, Issue 12. Art. No.: CD004736. DOI: 10.1002/14651858.CD004736.pub4

The effect of atorvastatin on blood lipids
Atorvastatin is one of the most widely consumed drugs and the most widely consumed drug in the statin class in the  world. It is therefore important to know the magnitude of effect that atorvastatin has on blood lipids. We searched for all the trial evidence from 3- to 12-week trials reporting the effect of atorvastatin on blood lipids. We found 254 trials in 33,505 participants. Atorvastatin had a consistent effect to lower blood total cholesterol, low-density lipoprotein (LDL)-cholesterol and triglycerides over the dose range of 2.5 to 80 mg daily. The effect was greater with higher doses than with lower doses. Manufacturer-recommended atorvastatin doses of 10 to 80 mg/day resulted in 36% to 53% decreases of LDL-cholesterol. Adverse effects of atorvastatin were not evident in these short-term trials but adverse effects were not reported in 37% of the trials.

Citation: Adams SP, Tsang M, Wright JM. Lipid lowering efficacy of atorvastatin. Cochrane Database of Systematic Reviews 2012, Issue 12. Art. No.: CD008226. DOI: 10.1002/14651858.CD008226.pub2

Green tea for weight loss and weight maintenance in overweight or obese adults
Green tea has a long history of many uses, one of which is helping overweight people to lose weight and to maintain weight loss. Believed to be able to increase a person's energy output, green tea weight loss preparations are extracts of green tea that contain a higher concentration of ingredients (catechins and caffeine) than the typical green tea beverage prepared from a tea bag and boiling water. This review looked at 15 weight loss studies and three studies measuring weight maintenance where some form of a green tea preparation was given to one group and results compared to a group receiving a control. Neither group knew whether they were receiving the green tea preparation or the control. A total of 1945 participants completed the studies, ranging in length from 12 to 13 weeks. In summary, the loss in weight in adults who had taken a green tea preparation was statistically not significant, was very small and is not likely to be clinically important. Similar results were found in studies that used other ways to measure loss in weight (body mass index, waist circumference). Studies examining the effect of green tea preparations on weight maintenance did not show any benefit compared to the use of a control preparation.

Most adverse effects, such as nausea, constipation, abdominal discomfort and increased blood pressure, were judged to be mild to moderate and to be unrelated to the green tea or control intervention. No deaths were reported, although adverse events required hospitalisation. One study attempted to look at health-related quality of life by asking participants about their attitudes towards eating. Nine studies tracked participants' compliance with green tea preparations. Studies did not include any information about the effects of green tea preparations on morbidity, costs or patient satisfaction.

Citation: Jurgens TM, Whelan AM, Killian L, Doucette S, Kirk S, Foy E. Green tea for weight loss and weight maintenance in overweight or obese adults. Cochrane Database of Systematic Reviews 2012, Issue 12. Art. No.: CD008650. DOI: 10.1002/14651858.CD008650.pub2