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.

The benefits of commonly used blood pressure and cholesterol lowering treatment can last 16 years
Fewer deaths from stroke had occurred in people who had high blood pressure treated with amlodipine, a calcium-channel blocker, compared to atenolol, 10 years after the end of a large trial. People with high blood pressure who took statins were less likely to die from cardiovascular diseases, such as heart disease or stroke than those taking a placebo. This study followed over 7,000 UK patients who had taken part in a clinical trial of blood pressure and cholesterol-lowering treatments between 1998 and 2005. It compared those who had been allocated to amlodipine with those who took atenolol. Those in either blood pressure group who had not already received a statin were also randomised to either atorvastatin (a cholesterol-lowering drug) or placebo. Some caution is needed in interpreting these findings because no details were available on what treatments were taken after the trial ended. Both arms of the original trial were stopped early because of the superiority of amlodipine-based treatment over atenolol-based treatment and atorvastatin over placebo. But it is likely that all groups received similar post-trial management according to best practice at the time. The results add important information for clinicians and patients considering the long-term implications of taking these medications.
15 January 2019

Home-based cardiac rehabilitation for heart failure has high rates of participation
Home-based cardiac rehabilitation for people with heart failure improves quality of life at 12 months compared with usual care. Among those allocated to rehabilitation, 90% remained in the programme – more than double average attendance rate for hospital-based rehabilitation. The average cost was estimated at £418 per participant which is within the National Health Service tariff for cardiac rehabilitation in England of £477 per patient. This NIHR-funded trial included 216 participants from four primary and secondary care centres across the UK. The home-based programme was facilitated by a trained cardiac nurse or physiotherapist via face-to-face and telephone sessions and included a choice of two home-based exercise programmes, a patient progress tracker and a caregiver resource. Despite the proven effectiveness of cardiac rehabilitation programmes in reducing readmissions and risk of death from heart disease, attendance varies widely across the UK and is generally poor.This home-based programme appears acceptable, affordable and safe, with higher levels of participation than have been seen previously in hospital-based programmes.
08 January 2019

Antidepressants do not help treat depression in people living with dementia
Antidepressants do not reduce symptoms of depression in people with dementia compared with placebo (dummy pills). Measured 6 to 13 weeks after starting the treatment, there is little or no difference in participants’ symptoms, but an increased chance of unwanted side effects. The review did not identify enough data to determine if antidepressants have an effect in the longer-term. This Cochrane review included randomised controlled trials of any antidepressant drugs compared to placebo. Participants were aged 75 years on average, with mild or moderate dementia. The quality of the included trials was mixed, with not enough information reported to fully assess the risk of bias, though the main result is reliable. This review supports the NICE guideline, which recommends that antidepressants are not routinely offered to people with dementia and depression, but that psychological treatments are considered instead.
08 January 2019

Thyroid hormone treatment does not help adults with mildly abnormal thyroid tests
There appears to be no benefit from treating adults with subclinical hypothyroidism. Treatment has no effect on quality of life or symptoms compared with placebo or no treatment. Thyroid function tests are commonly performed in general practice for patients who present with a range of symptoms, including fatigue or tiredness. When subclinical hypothyroidism is detected, there is uncertainty whether treatment is worthwhile or how to best monitor success. A recent large study found that hormone levels remain remarkably stable over five years, with few people developing overt hypothyroidism without treatment, suggesting monitoring could be reduced. This review of 21 trials provides moderate to high-quality evidence that hormone treatment of subclinical hypothyroidism, gives no measurable benefit either. This may help inform practice, spare patients unnecessary treatment, and save NHS resources.
08 January 2019

Pelvic floor muscle training can improve symptoms of urinary incontinence
Two-thirds of women with any type of urinary incontinence who have pelvic floor muscle training see improvement or cure compared with only a third of women who receive no treatment or inactive treatments. It is even more effective for women with stress incontinence, with three-quarters of women reporting improvement or resolution of symptoms, such as episodes of leakage. This systematic review included 31 trials and 1,817 women with any type of incontinence; stress, urgency or mixed urinary incontinence. Findings support current guidelines to offer pelvic floor exercises as first-line conservative management in women with urinary incontinence. Long-term effectiveness and cost-effectiveness require further evaluation.
02 January 2019

The best dose of aspirin for cardiovascular protection may depend on body weight
Low dose aspirin only appears to be effective at preventing stroke or heart attack for people weighing less than 70kg, while higher doses are better for people who weigh over 70kg. Researchers analysed data from 13 trials of aspirin for primary or secondary prevention of cardiovascular events, totalling over 115,000 participants. They found that 75 to 100mg aspirin only benefitted people who weighed less than 70kg, while only those who weighed 70kg or more benefited from doses of 325mg or above. This NIHR-funded trial suggests that prescribing the same dose to people of all weights is unlikely to be ideal and, if aspirin is indicated, dose adjustments by weight are required. UK guidelines do not recommend routine treatment with aspirin for people who do not have cardiovascular disease because of the increased risk of bleeding. However, for people at high risk of heart attack or stroke, the benefits may outweigh this increased risk. This study suggests that the dose may also need to be adjusted according to a person’s weight.
18 December 2018

Diet and exercise can reduce the risk of developing diabetes during pregnancy
Diet and exercise are effective ways of preventing the development of diabetes during pregnancy, known as gestational diabetes. Gestational diabetes is becoming more common and is associated with poorer outcomes for mother and baby. Diet, physical activity and weight are modifiable risk factors, but trials published to date have shown inconsistent results. This systematic review pooled 47 trials and found that any form of lifestyle intervention reduced the risk of gestational diabetes by 23%, with similar effects for diet, exercise or both. Interventions were most successful when targeted at high-risk populations, though body mass index alone was not associated with an effect. As the authors suggest, comprehensive risk assessments that consider body mass index alongside other risk factors may help to identify women who could benefit most from structured lifestyle interventions during pregnancy.
18 December 2018

A total diet replacement programme helped obese people lose weight and keep weight off
A programme of weekly behavioural support with total diet replacement led to over 7kg greater weight loss than usual care in primary care. This weight loss was maintained for a year after starting the 8-12 week low calorie programme. This trial, funded by NIHR and a commercial sponsor, was carried out in ten primary care practices in Oxfordshire. Participants had BMI over 30. It referred half of the 278 participants to a commercial weight loss programme, free of charge for six months. The rest of the participants received usual care from their practice for 12 weeks. Participants initially replaced all food with four formula food products daily (soups, shakes, and bars) containing 810 kcal per day. After eight weeks of this low calorie diet, conventional meals were gradually reintroduced. This trial provides evidence that the rapid weight loss from these replacement diets can be maintained for a reasonable time and so could be considered as a treatment option for anyone who is obese and needs support to lose weight.
18 December 2018

Benzodiazepines may increase length of stay and chance of delirium in intensive care
Benzodiazepines given during mechanical ventilation in intensive care could increase the risk of a longer hospital stay and delirium compared to other sedatives. A range of sedatives are used to reduce psychological distress in critically ill patients, but prior to this study, it was not clear which drugs are most effective. This systematic review looked at all the evidence from randomised controlled trials for the effectiveness of six different types of sedative used in people given mechanical ventilation. It then compared each drug type with each other, and placebo. There was no difference between type of sedation in the number of patients who survived and were discharged from intensive care. Results suggest benzodiazepines prolong the length of stay in intensive care compared with propofol and increase the risk of delirium compared with dexmedetomidine.
18 December 2018

Aspirin did not prevent deaths or disability in healthy older adults
In the ASPREE trial, older adults with no apparent cardiovascular disease who took daily aspirin saw no benefit in terms of reducing the chance of dying or having dementia or disability. Instead, it slightly increased their mortality and bleeding risk - aspirin was associated with an excess of 1.6 deaths per 1,000 people per year. Half of these deaths were due to cancer. Aspirin is an established ‘secondary’ preventative treatment for people who have known cardiovascular disease. However, the risk-benefit balance of aspirin for ‘primary’ prevention in people without known cardiovascular disease is debated. This large trial enrolled over 19,000 community-dwelling adults aged over 70 years and assigned them to aspirin – at the dose of 100mg – or matching placebo. The cancer association is unexpected and is at odds with most other research suggesting aspirin might decrease cancer risk, or be neutral. So, with only five years follow-up, this finding needs cautious interpretation at this stage. Nevertheless, this research supports guideline recommendations which do not include aspirin as part of primary prevention in older people.
18 December 2018

More findings are available on the NIHR Dissemination Centre website.