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
Wearing stockings to provide compression for the treatment of varicose veins
Evidence from randomised controlled trials is not sufficient to determine if compression stockings as the only and initial treatment are effective in managing and treating varicose veins in the early stages. Varicose veins are widened veins that twist and turn and are visible under the skin of the leg. They generally do not cause medical problems although many sufferers seek medical advice. Symptoms that may occur include pain, ankle swelling, tired legs, restless legs, night cramps, heaviness, itching and distress from their cosmetic appearance. Complications such as oedema, pigmentation, inflammation and ulceration can also develop. Compression stockings are often the first line of treatment and come in a variety of lengths, knee length to full tights, and apply different pressures to support the flow of blood in the veins.
Seven studies involving 356 participants with varicose veins and who had not experienced venous ulceration were included in this review. One study assessed compression hosiery versus no compression hosiery. The other six compared different types or pressures of stockings, ranging from 10 to 50 mmHg. The methodological quality of the included trials was unclear and not all studies assessed the same outcomes. One study included only pregnant women whilst other studies included participants who were on surgical waiting lists, that is, people who had sought medical intervention for their varicose veins.
The participants' subjective symptoms, and foot swelling and blood flow (physiological measures) improved in all of the studies that assessed these outcomes when stockings were worn, but these assessments were not made by comparing one randomised arm of the trial with a control arm in the same study. Conclusions from the individual studies regarding the optimum pressure provided by stockings were conflicting, although the results of one study suggested that lower pressured stockings (20 mmHg) may be as effective as higher pressured stockings (30 to 40 mmHg) for relieving symptoms. Conclusions regarding the optimum length of the stockings were inconclusive. No severe or long lasting side effects were noted.
Citation: Shingler S, Robertson L, Boghossian S, Stewart M. Compression stockings for the initial treatment of varicose veins in patients without venous ulceration. Cochrane Database of Systematic Reviews 2013, Issue 12. Art. No.: CD008819. DOI: 10.1002/14651858.CD008819.pub3
Vitamin A for preventing blindness in children with measles
Annually 500,000 children become blind worldwide, 75% of them living in low-income countries. The major causes of blindness in children vary widely from region to region and are related to the standard of living of the community. Corneal scarring from measles, vitamin A deficiency, use of harmful traditional eye remedies and ophthalmia neonatorium (newborn conjunctivitis) are the major causes in low-income countries. Vitamin A is an important nutrient in the body and is required for the normal functioning of the eye. Its deficiency results in poor vision.
Measles infection in children has been associated with vitamin A deficiency and blindness. The control of blindness in children is considered a high priority within the World Health Organization's VISION 2020 The Right to Sight Program. Studies have reported the beneficial effect of vitamin A in reducing morbidity and mortality in children with measles. This review examined vitamin A use in preventing blindness in children infected with measles without features of vitamin A deficiency. We included two randomised controlled trials of moderate quality, including 260 children with measles comparing vitamin A with placebo. Two doses of vitamin A given on two consecutive days to hospitalised children with measles significantly increased the blood concentration of vitamin A after one week.
However, there is a limitation in that neither of the two included studies reported blindness or other ocular morbidities as end points in children infected with measles. The sample size of the included studies was also relatively small which could affect the precision of the estimates given. Also no adverse event was reported in the included studies. We do not have sufficient evidence to demonstrate the benefit or otherwise of vitamin A in the prevention of blindness in children infected with measles.
The evidence is current to March 2013.
Citation: Bello S, Meremikwu MM, Ejemot-Nwadiaro RI, Oduwole O. Routine vitamin A supplementation for the prevention of blindness due to measles infection in children. Cochrane Database of Systematic Reviews 2014, Issue 1. Art. No.: CD007719. DOI: 10.1002/14651858.CD007719.pub3
Treadmill training and body weight support for walking after stroke
Question: We wanted to assess whether treadmill training and body weight support, individually or in combination, could improve walking when compared with other gait training methods, placebo or no treatment.
Background: About 60% of people who have had a stroke have difficulties with walking, and improving walking is one of the main goals of rehabilitation. Treadmill training, with or without body weight support, uses specialist equipment to assist walking practice.
Study characteristics: We identified 44 relevant trials, involving 2658 participants, up to June 2013. Twenty-two studies (1588 participants) compared treadmill training with body weight support to another physiotherapy intervention; 16 studies (823 participants) compared treadmill training without body weight support to other physiotherapy intervention, no intervention or sham; two studies (100 participants) compared treadmill training with body weight support to treadmill training without body weight support; and four studies (147 participants) did not state whether they used body weight support or not. The average age of the participants ranged from 50 to 75 years, and the studies were carried out in both inpatient and outpatient settings.
Key results and quality of the evidence: The results of this review were partly conclusive. People after stroke who receive treadmill training with or without body weight support are not more likely to improve their ability to walk independently. The quality of this evidence was low. However, treadmill training with or without body weight support may improve walking speed and walking capacity compared with people not receiving treadmill training. The quality of this evidence was moderate. More specifically, people after stroke who are able to walk at the start of therapy appear to benefit most from this type of intervention, but people who are not able to walk independently at therapy onset do not benefit. This review found that improvements in walking speed and endurance in people who can walk may have persisting beneficial effects. However, our review suggests that stroke patients who are not able to walk independently at the start of treatment may not benefit from treadmill training with or without body weight support. Adverse events and drop outs did not occur more frequently in people receiving treadmill training. Subgroup analysis showed that treadmill training in the first three months after stroke produces statistically and clinically relevant improvements in walking speeds and endurance. For people treated in the chronic phase (i.e. more than six months post-stroke) the effects were lower. Treadmill training at higher frequencies may produce greater effects on walking speed and endurance; however, this was not significant.
In practice, treadmill training should be used when stroke patients can walk independently. Therapists should be aware that treadmill training may be used as an option but not as a stand-alone treatment to improve walking speed and endurance in people who are able to walk independently. It appears that people who can walk after stroke, but not those who cannot, may profit from treadmill training (with and without body weight support) to improve their walking abilities. Further research should specifically investigate the effects of different frequencies, durations or intensities (in terms of speed increments and inclination) of treadmill training, as well as the use of handrails. Future trials should include people who can already walk, but not dependent walkers who are unable to walk unaided.
Citation: Mehrholz J, Pohl M, Elsner B. Treadmill training and body weight support for walking after stroke. Cochrane Database of Systematic Reviews 2014, Issue 1. Art. No.: CD002840. DOI: 10.1002/14651858.CD002840.pub3.
Decision aids for people facing health treatment or screening decisions
Identifying and making a decision about the best health treatment or screening option can be difficult for patients. Decision aids can be used when there is more than one reasonable option, when no option has a clear advantage in terms of health outcomes, and when each option has benefits and harms that patients may value differently. Decision aids may be pamphlets, videos, or web-based tools. They make the decision explicit, describe the options available, and help people to understand these options as well as their possible benefits and harms. This helps patients to consider the options from a personal view (e.g., how important the possible benefits and harms are to them) and helps them to participate with their health practitioner in making a decision.
The updated review, with searches updated in June 2012, includes 115 studies involving 34,444 participants. Findings show that when patients use decision aids they: a) improve their knowledge of the options (high-quality evidence); b) feel more informed and more clear about what matters most to them (high-quality evidence); c) have more accurate expectations of possible benefits and harms of their options (moderate-quality evidence); and d) participate more in decision making (moderate-quality evidence). Patients who used decision aids that included an exercise to help them clarify what matters most to them, were more likely to reach decisions that were consistent with their values. However, the quality of the evidence was moderate for this outcome, meaning that further research may change these findings. Decision aids reduce the number of patients choosing prostate specific antigen testing and elective surgery when patients consider other options. They have a variable effect on most other actual choices. Decision aids improve communication between patients and their health practitioner. More detailed decision aids are better than simple decision aids for improving people's knowledge and lowering decisional conflict related to feeling uninformed and unclear about their personal values. Decision aids do not worsen health outcomes and people using them are not less satisfied. More research is needed to evaluate adherence with the chosen option, the associated costs, use with patients who have more limited reading skills, and the level of detail needed in a decision aid.
Citation: Stacey D, Légaré F, Col NF, Bennett CL, Barry MJ, Eden KB, Holmes-Rovner M, Llewellyn-Thomas H, Lyddiatt A, Thomson R, Trevena L, Wu JHC. Decision aids for people facing health treatment or screening decisions. Cochrane Database of Systematic Reviews 2014, Issue 1. Art. No.: CD001431. DOI: 10.1002/14651858.CD001431.pub4
Vitamin D supplementation for prevention of mortality in adults
To assess the beneficial and harmful effects of vitamin D for prevention of mortality in healthy adults and adults in a stable phase of disease.
Numerous observational studies suggest that optimal vitamin D status may be associated with fewer occurrences of cancer and cardiovascular disease (such as heart attack or stroke). Vitamin D is synthesised in the skin as vitamin D3 (cholecalciferol) or is obtained from dietary sources or supplements as vitamin D3 or vitamin D2 (ergocalciferol). Our Cochrane systematic review from 2011, which analysed the influence of different forms of vitamin D on mortality, showed that vitamin D3 (cholecalciferol) decreased mortality. This systematic review is now updated, and all included trials have been reassessed in accordance with improved Cochrane methodology, developed to enhance the validity of the conclusions.
In the 56 trials that provided data for the analyses, a total of 95,286 participants were randomly assigned to vitamin D versus no treatment or placebo. More than half of the trials were considered to have low risk of bias. All trials were conducted in high-income countries. The age of participants ranged from 18 to 107 years. The mean proportion of women was 77%. Vitamin D was administered for an average of 4.4 years.
This plain language summary is as current as of February 2012.
This review suggests that vitamin D3 may reduce mortality, showing that about 150 participants need to be treated over five years for one additional life to be saved. We found comparable effects of vitamin D3 in studies that included only women compared with studies including both women and men. Vitamin D3 also seemed to decrease cancer mortality, showing a reduction in mortality of 4 per 1000 persons treated for five to seven years. We also observed adverse effects to vitamin D such as renal stone formation (seen for vitamin D3 combined with calcium) and elevated blood levels of calcium (seen for both alfacalcidol and calcitriol). In conclusion, we found some evidence that vitamin D3 seems to decrease mortality in elderly people not dependent on help or living in institutional care.
Quality of the evidence
A large number of study participants left the trial before completion, and this raises concerns regarding the validity of the results. More randomised clinical trials are needed on the effects of vitamin D3 on mortality in younger, healthy persons, as well as in elderly community-dwelling and institutionalised persons without apparent vitamin D deficiency.
Citation: Bjelakovic G, Gluud LL, Nikolova D, Whitfield K, Wetterslev J, Simonetti RG, Bjelakovic M, Gluud C. Vitamin D supplementation for prevention of mortality in adults. Cochrane Database of Systematic Reviews 2014, Issue 1. Art. No.: CD007470. DOI: 10.1002/14651858.CD007470.pub3.
|For more information, contact the South African Cochrane Centre on (021) 938 0834 or email Joy.Oliver@mrc.ac.za.