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.
Powered/electric toothbrushes compared to manual toothbrushes for maintaining oral health
This review has been conducted to assess the effects of using a powered (or 'electric') toothbrush compared with using a manual toothbrush for maintaining oral health.
Good oral hygiene, through the removal of plaque (a sticky film containing bacteria) by effective toothbrushing has an important role in the prevention of gum disease and tooth decay. Dental plaque is the primary cause of gingivitis (gum inflammation) and is implicated in the progression to periodontitis, a more serious form of gum disease that affects the tissues that support the teeth. The build up of plaque can also lead to tooth decay. Both gum disease and tooth decay are the primary reasons for tooth loss.
There are numerous different types of powered toothbrushes available to the public, ranging in price and mode of action. Different powered toothbrushes work in different ways (such as moving from side to side or in a circular motion). Powered toothbrushes also vary drastically in price. It is important to know whether powered toothbrushes are more effective at removing plaque than manual toothbrushes, and whether their use reduces the inflammation of the gums (gingivitis) and prevents or slows the progression of periodontitis.
Authors from the Cochrane Oral Health Group carried out this review of existing studies and the evidence is current up to 23 January 2014. It includes 56 studies published from 1964 to 2011 in which 5068 participants were randomised to receive either a powered toothbrush or a manual toothbrush. Majority of the studies included adults, and over 50% of the studies used a type of powered toothbrush that had a rotation oscillation mode of action (where the brush head rotates in one direction and then the other).
The evidence produced shows benefits in using a powered toothbrush when compared with a manual toothbrush. There was an 11% reduction in plaque at one to three months of use, and a 21% reduction in plaque when assessed after three months of use. For gingivitis, there was a 6% reduction at one to three months of use and an 11% reduction when assessed after three months of use. The benefits of this for long-term dental health are unclear.
Few studies reported on side effects; any reported side effects were localised and only temporary.
Quality of the evidence
The evidence relating to plaque and gingivitis was considered to be of moderate quality.
Citation: Yaacob M, Worthington HV, Deacon SA, Deery C, Walmsley AD, Robinson PG, Glenny AM. Powered versus manual toothbrushing for oral health. Cochrane Database of Systematic Reviews 2014, Issue 6. Art. No.: CD002281. DOI: 10.1002/14651858.CD002281.pub3
Zinc supplementation for preventing death and disease, and for growth, in children aged six months to 12 years of age
This review investigated the effectiveness of zinc supplementation for preventing illness and mortality, and for promoting growth, in children between six months and 12 years of age.
Zinc is an essential micronutrient and zinc deficiency is an important public health problem in low- and middle-income countries. Zinc deficiency impairs growth and contributes to numerous child deaths per year due to diarrhoea, pneumonia, and malaria. This review aimed to determine if giving children zinc supplements would help prevent child death, disease, and growth deficits.
We searched a wide range of electronic databases for studies that randomly assigned children aged six months to 12 years to either zinc supplementation or a control group that did not receive zinc. Eighty randomised studies with 205,401 eligible participants were included in this review. The evidence is current to December 2012.
Key results and the quality of the evidence
Giving children zinc supplements might reduce their risk of death in general, and their risk of death due to diarrhoea, lower respiratory tract infection (LRTI), or malaria. The quality of evidence for overall mortality was high, though evidence for other critical outcomes was only moderate. Children given zinc experience less diarrhoeal disease than children not given zinc; however, zinc does not seem to reduce children's risk of respiratory infection or malaria. Zinc supplementation may have a very small effect on growth, but eating more calories would probably have a larger effect for many malnourished children. Children who take zinc supplements may experience vomiting as a side effect.
Citation: Mayo-Wilson E, Junior JA, Imdad A, Dean S, Chan XHS, Chan ES, Jaswal A, Bhutta ZA. Zinc supplementation for preventing mortality, morbidity, and growth failure in children aged 6 months to 12 years of age. Cochrane Database of Systematic Reviews 2014, Issue 5. Art. No.: CD009384. DOI: 10.1002/14651858.CD009384.pub2
Yoga to prevent cardiovascular disease
Cardiovascular disease (CVD) is a global health burden. Nevertheless, it is thought that the risk of CVD can be lowered by changing a number of risk factors, such as by increasing physical activity and using relaxation to reduce stress, both of which are components of yoga. This review assessed the effectiveness of any type of yoga in healthy adults and those at high risk of CVD.
We searched scientific databases for randomised controlled trials (clinical trials where people are allocated at random to one of two or more treatments) looking at the effects of tai chi on adults at high risk of developing CVD. We did not included people who had already had CVD (e.g. heart attacks and strokes). The evidence is current to December 2013.
We found 11 trials (800 participants), none of them were large enough or of long enough duration to examine the effects of yoga on decreasing death or non-fatal endpoints.There were variations in the style and duration of yoga and the follow-up of the interventions ranged from three to eight months.The results showed that yoga has favourable effects on diastolic blood pressure, high-density lipoprotein (HDL) cholesterol and triglycerides (a blood lipid), and uncertain effects on low-density lipoprotein (LDL) cholesterol. None of the included trials reported adverse events, the occurrence of type 2 diabetes or costs. Longer-term, high-quality trials are needed in order to determine the effectiveness of yoga for CVD prevention.
Quality of the Evidence
These results should be considered as exploratory and interpreted with caution. This is because the included studies were of short duration, small and at risk of bias (where there was a risk of arriving at the wrong conclusions because of favouritism by the participants or researchers).
Citation: Hartley L, Dyakova M, Holmes J, Clarke A, Lee MS, Ernst E, Rees K. Yoga for the primary prevention of cardiovascular disease. Cochrane Database of Systematic Reviews 2014, Issue 5. Art. No.: CD010072. DOI: 10.1002/14651858.CD010072.pub2
Early (up to seven days) postnatal corticosteroids for preventing chronic lung disease in preterm infants
Corticosteroids can reduce lung inflammation in newborns with chronic lung disease, but there are major adverse effects of the drugs. Chronic lung disease is a major problem for newborn babies in neonatal intensive care units. Persistent inflammation of the lungs is the most likely cause. Corticosteroid drugs have been used to either prevent or treat chronic lung disease because of their strong anti-inflammatory effects. This review of trials found that the benefits of giving corticosteroids to infants up to seven days of age may not outweigh the known adverse effects. The beneficial effects were a shorter time on the ventilator and less chronic lung disease, but the adverse effects included high blood pressure, bleeding from the stomach or bowel, perforation of the bowel, an excess of glucose in the bloodstream and an increased risk of cerebral palsy at follow-up. Use of early corticosteroids, especially dexamethasone, to treat or prevent chronic lung disease should be curtailed until more research has been performed.
Citation: Doyle LW, Ehrenkranz RA, Halliday HL. Early (< 8 days) postnatal corticosteroids for preventing chronic lung disease in preterm infants. Cochrane Database of Systematic Reviews 2014, Issue 5. Art. No.: CD001146. DOI: 10.1002/14651858.CD001146.pub4
Kangaroo mother care to reduce morbidity and mortality in low birthweight infants
Kangaroo mother care (KMC) is an effective and safe alternative to conventional neonatal care in low birthweight (LBW) infants mainly in resource-limited countries.
Low birthweight (LBW) (less than 2500 g) is associated with an increased risk of neonatal morbidity and mortality, neurodevelopmental disabilities, and cardiovascular disease at adulthood. Conventional neonatal care of LBW infants is expensive and needs both highly skilled personnel and permanent logistic support. The major component of KMC is skin-to-skin contact (SSC) between a mother and her newborn. The other two components of KMC are frequent and exclusive or nearly exclusive breastfeeding and attempt of early discharge from hospital. Compared with conventional neonatal care, KMC was found to reduce mortality at discharge or 40-41 weeks' postmenstrual age and at latest follow up, severe infection/sepsis, nosocomial infection/sepsis, hypothermia, severe illness, lower respiratory tract disease, and length of hospital stay. Moreover, KMC increased weight, head circumference, and length gain, breastfeeding, mother satisfaction with method of infant care, some measures of maternal-infant attachment, and home environment. There were no differences in neurodevelopmental and neurosensory outcomes at one year of corrected age.
Citation: Conde-Agudelo A, Díaz-Rossello JL. Kangaroo mother care to reduce morbidity and mortality in low birthweight infants. Cochrane Database of Systematic Reviews 2014, Issue 4. Art. No.: CD002771. DOI: 10.1002/14651858.CD002771.pub3
Exercise-based rehabilitation for heart failure
People with heart failure experience marked reductions in their exercise capacity, which has detrimental effects on their activities of daily living, health-related quality of life and ultimately their hospital admission rate and mortality.
We searched the scientific literature for randomised controlled trials (experiments in which two or more interventions, possibly including a control intervention or no intervention, are compared by being randomly allocated to participants) looking at the effectiveness of exercise-based treatments compared with no exercise on heart failure in adults over 18 years of age. The inclusion criteria of this updated review were extended to consider not only HF due to reduced ejection fraction (HFREF or 'systolic HF') (ejection fraction is a measure of how well your heart is pumping), but also HF due to preserved ejection fraction (HFPEF or 'diastolic HF'). The search is current to January 2013.
We found 33 RCTs that included 4740 participants. The findings of this update are consistent with the previous (2010) version of this Cochrane review and show important benefits of exercise-based rehabilitation that include a reduction in the risk of hospital admissions due to HF and improvements in health-related quality of life compared with not undertaking exercise. There was a high level of variation across studies in health-related quality of life outcome. While the majority of evidence was for exercise-based rehabilitation in people with HFREF, this update did identify a broader evidence base that included higher risk (New York Heart Association class IV) and older people, people with HFPEF and more programmes conducted in a home-based setting. We found no evidence to suggest that exercise training programmes cause harm in terms of an increase in the risk of death in either the short or longer term. A small body of economic evidence was identified indicating exercise-based rehabilitation to be cost-effective. Further evidence is needed to understand the effect of exercise training in people with HFPEF better and the costs and effects of exclusively home-based exercise rehabilitation programmes.
Quality of evidence
The general lack of reporting of methods in the included trial reports made it difficult to assess their methodological quality and thereby judge their risk of possible bias.
Citation: Taylor RS, Sagar VA, Davies EJ, Briscoe S, Coats AJS, Dalal H, Lough F, Rees K, Singh S. Exercise-based rehabilitation for heart failure. Cochrane Database of Systematic Reviews 2014, Issue 4. Art. No.: CD003331. DOI: 10.1002/14651858.CD003331.pub4
For more information, contact the South African Cochrane Centre on (021) 938 0834 or email Joy.Oliver@mrc.ac.za.