Latest research findings

New research findings from the NIHR Dissemination Center

The NIHR Dissemination Centre puts good research evidence at the heart of decision making in the NHS, public health and social care. The centre critically appraises the latest health research to identify the most reliable, relevant and significant findings. It then disseminates these findings as:

NIHR Signals - The latest important research, summarised
NIHR Highlights - Conditions, treatments and issues explored using NIHR evidence
Themed Reviews - Bringing together NIHR research on a particular theme

To keep up to date with the latest important research, sign up to their mailing list or follow @NIHR_DC on twitter. Visit the Discover Portal for a complete, searchable selection of NIHR Signals, or see the latest on clinical trials below.

Alternative sedative reduces the risk of acute kidney injury following cardiac surgery
The sedative drug dexmedetomidine can reduce the risk of acute kidney injury when given during non-emergency cardiac surgery. Trial participants who received dexmedetomidine were a third less likely to develop acute kidney injury than those receiving placebo or other treatments. There was no difference in mortality or length of hospital stay. This systematic review identified 10 studies of 1,575 participants. Surgical procedures included coronary artery bypass grafting with or without valve surgery and aortic vascular surgery. Dexmedetomidine was given before or shortly after surgery. Most participants were followed up for the duration of their hospital stay, or for 12 to 30 days. Many strategies are currently used to reduce the risk of kidney injury following cardiac surgery. This study provides some evidence that dexmedetomidine may help reduce this risk, but larger trials are needed before it can be routinely recommended.
10 July 2018

One week of steroids may be as effective as two weeks in managing severe COPD
A shorter course of steroids lasting 3 to 7 days appears as effective as the recommended 7 to 14-day standard treatment for managing a flare-up of severe chronic obstructive pulmonary disease. This update to an earlier Cochrane review looked at randomised clinical trials comparing a short course (7 days or fewer) with a longer course (7 to 14 days) of steroids given by mouth or injection. All participants had been admitted to hospital, but none required mechanical ventilation. The evidence suggests that shorter courses of steroids could be given to people with severe chronic obstructive pulmonary disease where there are concerns about side effects. However, the research was limited by small study sizes and including only 582 people in total. Further research is needed to determine the optimum duration of steroid treatment in flare-ups of mild or moderate chronic obstructive pulmonary disease.
10 July 2018

Fish oil supplements are ineffective for treating dry eyes
Omega-3 fatty acids or ‘fish oil’ supplements are no more effective than inactive olive oil capsules for relieving dry eye disease. Some patients take fish oil supplements for this common problem, but this new evidence suggests that they consider alternatives. Dry eye disease is a common long-term inflammatory condition causing discomfort, and disturbances including blurred vision. Treatment of symptoms includes using artificial tears. Although guidelines recognise the lack of existing evidence for fish oil supplements, people continue to use them on the advice of health professionals. This US-based trial did not find a difference on several measures compared with placebo over one year of follow up. The trial was based on community patients, so is likely to apply to people visiting their GP for help with dry eye disease, or who buy supplements over the counter. Practitioners can now confidently tell their patients that new evidence suggests this widely available supplement is no better than taking olive oil for relieving dry eye symptoms.
03 July 2018

Cartoons are promising for reducing dental anxiety in children
Cartoons delivered on laptops, projectors or 3D goggles with sound can help distract anxious children who fear dental procedures. Dental anxiety can prevent children from attending the dentist for care, and this type of distraction could offer a useful tool to help them. This review looked at a range of audiovisual approaches tested in trials of healthy children receiving dental treatment under local anaesthetic. The children were assessed for physiological measures related to emotional state (such as pulse rate), anxiety and observed behaviour. Childhood dental anxiety is a common problem, and these distraction approaches sound promising, safe and relatively easy to implement.
03 July 2018

Yoga-based exercise can improve well-being for older people
Yoga-based exercise offers a safe and accessible way to improve health-related quality of life and mental well-being for people over 60. Evidence for a moderate benefit of yoga in later life now extends beyond improved balance and flexibility. Yoga includes stretches, poses, breathing routines and meditation. This review focused on the physical exercise/activity components. Most of the 12 included trials took place in Western countries and classes were all run by qualified yoga instructors as in the UK. Class attendance was high for eight weeks or more (50 to 96%). However, women outnumbered men by three to one, implying that yoga classes may need adapting to appeal to older men. Yoga classes are widely available and could offer an accessible way to improve older people’s activity levels and well-being. The research was moderate to high quality, but it cannot yet show exactly how much yoga or which kind works best for particular groups of people. However, the good news is that these approaches seem effective.
26 June 2018

Cannabis derivative may reduce seizures in some severe drug-resistant epilepsies, but adverse events increase
In people with some types of severe, drug-resistant epilepsy, adding cannabidiol to their treatment may reduce seizure frequency and improve quality of life compared with a placebo. The likelihood of being free from seizures for more than a year was still low, about 8%. However, an additional 12% of people had serious adverse effects with cannabidiol. These findings come from a systematic review, which included six trials in 555 patients. Most were children and adolescents with rare forms of epilepsy, and findings may not apply to other forms of the condition. The included trials were poorly reported and show some bias. Further, more reliable research is needed and may produce different results. Cannabidiol does not currently have approval for medicinal use in the UK for this purpose and will require more independent research before it is used with any confidence.
26 June 2018

Group-based diet and exercise programmes can lead to weight loss
The evidence is growing that group-based weight loss programmes can offer effective and acceptable options for overweight people, particularly men. On average, people in group dietary advice and exercise programmes lose 3.5kg more than non-participants by six months – a modest 4% weight loss overall but less than the 5% that is often regarded as clinically important. In this systematic review on the group weight loss approach, participants in the 47 trials were adults from the general population, taking part in groups of at least three people, led by a facilitator. The interventions varied considerably in setting, contact time, group size, facilitators’ background and intervention content. This wide variation and reporting limitations mean that it is difficult to determine exactly what works and how. The group approach seems generally effective, more so for men than women, and is more effective in those programmes that target weight loss rather than maintenance.
26 June 2018

Balanced electrolyte solutions give marginal benefit over saline for very ill patients
About 14% of critically ill patients receiving electrolyte-balanced crystalloids either developed kidney failure, needed kidney-replacement therapy or died compared with 15% receiving normal saline. This small but statistically significant benefit was only apparent when combining outcomes; there was no difference between fluids for the three individual outcomes analysed separately. A solution of 0.9% sodium chloride (normal saline) is the most commonly used intravenous (IV) fluid, but it can cause biochemical imbalance. Alternative crystalloids like Ringer's lactate or Hartmann’s solution contain an electrolyte composition closer to normal blood fluid and are often seen as preferable. This US trial compared 30-day outcomes for over 15,000 critical patients randomised to either fluid type. The difference in outcomes between fluid types was very small, but there is a difference in cost. The small benefit perhaps argues against routine use of balanced crystalloids in all patients. Though what is most important is that the fluid and electrolyte needs of the individual are recognised and met.
19 June 2018

Fewer side-effects and similar benefits from shorter chemotherapy after bowel cancer surgery
A three-month course of chemotherapy after surgery for bowel cancer seems no less effective than the standard six-month course, and half as many people suffered from nerve damage as a side-effect. Three-quarters of people survived to three years without disease progression on either treatment. This international trial, part funded by the NIHR, included over 6,000 people with high-risk stage II or III bowel cancer that had spread through the bowel wall or to nearby lymph nodes. Standard treatment after surgery is usually six months of an oxaliplatin-containing regimen. This study evaluated a shorter course. Oxaliplatin is known to damage nerves, causing numbness, tingling and pain in feet and hands, which tends to get worse with prolonged use. Shorter chemotherapy reduced the frequency and severity of such side effects. Shorter course chemotherapy could become an option to discuss with patients when balancing the benefits and risks of treatment.
12 June 2018

Single routine offer of a blood test for prostate cancer did not save lives
Offering all men aged 50 to 69 a single, screening prostate-specific antigen (PSA) blood test did not prevent deaths from prostate cancer. This large trial included 573 UK general practices and over 400,000 men. It found that men who were invited to have a PSA test were 19% more likely to be diagnosed with prostate cancer, but no less likely to die from the condition, over an average 10 years of follow up. Forty per cent of men took up the offer. Controversy over PSA testing has persisted for many years. Two previous trials have had conflicting findings about whether repeated PSA testing reduces prostate cancer deaths. In addition, concerns about test accuracy, over-diagnosis and over-treatment have meant that PSA testing is not routinely offered on the NHS to men with no symptoms. The current study supports the idea that one-off PSA screening in this age group is not likely to be of benefit.
12 June 2018

More findings are available on the NIHR Dissemination Centre website.