Tag Archives: Peter Chilton

Education Before Surgery

Within developed countries the most frequently performed major surgery is of the upper abdomen. However, research has shown that between 10-50% of patients suffer a postoperative pulmonary complication (PPC), which is strongly associated with an increase in mortality and morbidity, as well as healthcare costs. Some studies have suggested that education and training in breathing exercises prior to the surgery could reduce the risk of developing PPC (75% reduction in relative risk, 20% reduction in absolute risk), but these studies may have been subject to methodological biases. Now researchers in Australia have conducted an international, multicentre, blinded, parallel group RCT to assess the efficacy of preoperative physiotherapy in reducing PPCs.[1] They enrolled 441 patients to receive an information booklet alone (control), or with an additional 30-minute physiotherapy education and breathing exercise training session. The intervention group saw a significant reduction in the incidence of PPC (including hospital-acquired pneumonia) within 14 days of the operation (adjusted hazard ratio 0.48, 95% CI 0.30-0.75). This amounted to an absolute risk reduction of 15% (95% CI 7-22%).

— Peter Chilton, CLAHRC WM Research Fellow

Reference:

  1. Boden I, Skinner EH, Browning L, Reeve J, Anderson L, Hill C, Robertson IK, Story D, Denehy L. Preoperative physiotherapy for the prevention of respiratory complications after upper abdominal surgery: pragmatic, double blinded, multicentre randomised controlled trial. 2018; 360: j5916.
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Involving Families in Neonatal Care

It is an unfortunate fact that some children need to be admitted into a neonatal intensive care unit (NICU) soon after birth, and this physical separation can often impact on the physical, psychological and emotional health of both the parents and the babies. In many NICUs the parents are expected to take a step back, with NICU staff providing the great majority of day-to-day care of the baby. An alternative approach, that is not widely used, is the Family Integrated Care (FICare) programme, which facilitates collaboration between parents and the NICU staff. Parents become involved in all aspects of their baby’s care, such as feeding, changing, bathing, as well as decision-making and taking part in medical rounds. A recent paper in the Lancet Child and Adolescent Health looked at the effectiveness of an FICare programme in 26 NICUs in Canada, Australia and New Zealand.[1] Premature babies (born at 33 weeks or earlier) were randomly assigned to receive standard NICU care (n=891), or be provided with FICare (n=895). Parents in the FICare group had to commit to be present for at least six hours each day, attend educational sessions, and provide active care for their baby. At 21 day follow-up the babies in the FICare group had significantly greater weight gain and an average daily weight gain of 26.7g (vs. 24.8g) (both p<0.0001). Mothers in the FICare group also had significantly higher rates of exclusive breastmilk feeding (p=0.016).  Further, parents had significantly lower scores on mean levels of stress (p<0.00043) and anxiety (p=0.0045). There were no significant differences in mortality, major morbidity, oxygen therapy duration, or length of hospital stay.

— Peter Chilton, Research Fellow

Reference:

  1. O’Brien K, Robson K, Bracht M, et al. Effectiveness of Family Integrated Care in neonatal intensive care units on infant and parent outcomes: a multicentre, multinational, cluster-randomised controlled trial. Lancet Child & Adol Health. 2018.

How Accurate are Computer Algorithms Really?

The use of computers to replace tasks previously done by hand continues to become more prevalent, from using machine learning to analyse database studies,[1] to algorithms that recommend whether someone should receive a bank loan or be shortlisted for a job interview. Another area that uses such predictive algorithms is in the criminal justice system, where they are often used to predict criminal behaviour, such as locations of crime ‘hotspots’, the likelihood of whether defendants will attend their court hearing, and/or whether someone will reoffend. However, there is concern as to the accuracy and fairness of these systems.[2]

In an article in Science Advances,[3] Dressel and Faris compared a commercially available criminal risk assessment tool against assessment by untrained participants on accuracy of deciding whether a defendant would reoffend within two years. These participants were recruited via an online system and paid $1, with a bonus of $5 if the accuracy of their predictions was high (to incentivise them to treat the task seriously). The computer algorithm assessed 137 features of 1000 defendants and their past criminal record, while the volunteers were given a statement containing seven features (sex, age, criminal history) of a subset of 50 defendants. Comparing the results showed no significant difference (p=0.045) between the accuracy of the algorithm (65.2%) and the participants (62.8%). Pooling the participant responses (‘wisdom of the crowd’) showed similar accuracy (67.0%) (p=0.85). Further analysis showed that participants’ prediction accuracy were slightly more sensitive and less biased than that of the algorithm; while they were similar in terms of fairness regarding race of the defendant. Perhaps with participants who are well versed in criminal justice, or who are well trained, their accuracy could be higher than that of the computer?

The authors then went on to recreate the accuracy of the commercial computer algorithm using a simpler standard linear predictor, and found that inputting only two features (age and total number of previous convictions) gave results as accurate as the algorithm using 137 features.

— Peter Chilton, Research Fellow

References:

  1. Lilford RJ. Machine Learning and the Demise of the Standard Clinical Trial! NIHR CLAHRC West Midlands News Blog. 10 November 2017.
  2. Lilford RJ. Machine Learning. NIHR CLAHRC West Midlands News Blog. 11 November 2016.
  3. Dressel J & Farid H. The accuracy, fairness, and limits of predicting recidivism. Sci Adv. 2018; 4(1): eeao5580.

Intraperitoneal Chemotherapy for Ovarian Cancer

The CLAHRC WM Director hates ovarian cancer – it spreads throughout the abdominal cavity and is horrible to behold it at surgery. He has often wondered if topical chemotherapy could help control this dreaded disease. In the UK one in 52 women will be diagnosed with ovarian cancer within their lifetime, with around 7,400 new cases and around 4,100 deaths in 2014.[1] Standard treatment is surgery to excise the tumour, followed by intravenously administered chemotherapy, or vice-versa. Can topical (intraperitoneal) chemotherapy improve outcomes compared to the standard intravenous method? Previous research of combined intravenous and intraperitoneal chemotherapy has shown an increase in overall survival in patients with ovarian cancer, but there are a number of limitations that have affected widespread adoption. Researchers in the Netherlands conducted a study to see if delivering the intraperitoneal chemotherapy immediately after surgery could show similar effectiveness, while overcoming these limitations.[2]

This was a randomised trial of 245 patients with ovarian cancer who had already undergone three cycles of chemotherapy. Patients underwent surgery with hyperthermic intraperitoneal chemotherapy (HIPEC) administered at the end of the procedure or not, followed by another three cycles of chemotherapy. HIPEC is where the abdomen is heated prior to applying the chemotherapy drugs. This hyperthermia results in a number of cellular reactions, including increasing the penetration of chemotherapy drugs into the tissue, impairing the ability of cancer cells to repair DNA, thus increasing their sensitivity, and inducing apoptosis.

Results showed significantly fewer deaths and disease recurrence in those patients who underwent HIPEC immediately during surgery, than in those who did not (hazard ratio 0.66, 95% CI 0.50-0.87; p=0.003). Further the patients in the HIPEC group had a median recurrence-free survival of 14.2 months, compared to 10.7 months. At follow-up (median of 4.7 years), 62% of patients who had undergone surgery without HIPEC had died, compared to 50% of patients who had received HIPEC (p=0.02). Median survival was 45.7 months compared to 33.9 months. Adverse events were similar in both groups.

— Peter Chilton, Research Fellow

References:

  1. Cancer Research UK. Ovarian Cancer Statistics. 2018.
  2. van Driel WJ, Koole SN, Sikorska K, et al. Hyperthermic Intraperitoneal Chemotherapy in Ovarian Cancer. New Engl J Med. 2018; 378: 230-40.

A Calming Scent

In a previous News Blog we looked at a study investigating associations between body odour and attractiveness to strangers.[1] But what about the smell of someone we already love? A recent study randomly assigned 96 women to smell the scent of either their partner, a stranger, or a neutral unworn shirt, before exposing them to stress through a standardised mock job interview and an unanticipated mental arithmetic task.[2] The results found that women exposed to their partner’s scent perceived lower levels of stress both before and after the stressor task (though not during). Further women exposed to a stranger’s scent had higher levels of cortisol throughout the study, which is released in response to stress.

Perhaps providing worn clothing from a loved one could be a useful coping strategy for people who have been separated, for example, in elderly patients in care homes.

— Peter Chilton, Research Fellow

References:

  1. Lilford RJ. The Scent of a Woman – Not as Important as Once Thought. NIHR CLAHRC West Midlands News Blog. 24 November 2017.
  2. Hofer MK, Collins HK, Whillans AV, Chen FS. Olfactory Cues From Romantic Partners and Strangers Influence Women’s Responses to Stress. J Person Soc Psychol. 2018; 114(1): 1-9.

Risks of Children Using Technology Before Bed

We live in an increasingly technologically connected society, which even extends to children – for example, 74% of children (9-16 years old) in the UK use a mobile phone, with most receiving their first phone at the age of 10 years old;[1] while around half have a television in their bedroom at age 7.[2] For many it can be difficult to switch off at the end of the day – the allure of one more video, or another scan of social media can be strong. As such, many children use technology at bedtime, which may impact on their sleep as the light emitted by these devices has a higher concentration of ‘blue light’, which affects the levels of melatonin, a sleep-inducing hormone.[3] Previous research has shown the importance of sleep on children’s health and behaviour, and so Fuller and colleagues conducted a study looking at use of technology at bedtime and its effects on various health outcomes.[4] They surveyed 207 parents of 8-17 year olds and found that children who watched television at bedtime were significantly more likely to be overweight or obese than those who did not (odds ratio 2.4, 95% CI 1.35-4.18). Similar results were found for children who used a phone at bedtime (OR=2.3, 95% CI 1.31-4.05). There were no significant differences seen with computer or video game use. The authors also looked at sleeping behaviour and found a significant relationship between average hours of sleep and bedtime use of television (P=0.025), phone (P<0.001), computer (P<0.001), and video games (P=0.02). Further analysis showed that children who used various technologies were also more likely to be tired in the morning, less likely to eat breakfast, and more likely to text during the middle of the night. The authors recommend setting up ‘tech-free’ zones and making sure that devices are charged outside of the child’s bedroom.

Of course, this study only shows an association – it may be that some children have difficulty getting to sleep and so turn to technology in order to help them drift off. Meanwhile, the study is subject to reporting bias from the self-reported surveys of the parents, and so further studies are needed.

— Peter Chilton, Research Fellow

References:

  1. GSMA report. https://www.gsma.com/publicpolicy/wp-content/uploads/2012/03/GSMA_Childrens_use_of_mobile_phones_2014.pdf. 2014.
  2. Heilmann A, Rouxel P, Fitzsimons E, Kelly Y, Watt RG. Longitudinal associations between television in the bedroom and body fatness in a UK cohort study. Int J Obes. 2017; 41: 1503-9.
  3. Fuller C, Lehman E, Hicks S, Novick MB. Bedtime Use of Technology and Associated Sleep Problems in Children. Glob Pediatr Health. 2017.
  4. Schmerler J. Q&A: Why Is Blue Light before Bedtime Bad for Sleep? Scientific American. 01 September 2015.

Reducing Radiation Risk from Hospital Scans

Even though it is something carried out in hospitals hundreds of times a day, X-rays and CT (computed topography) scans are procedures that expose the patient to radiation. Yes, the radiation dosage for the majority of scans carried out is very little when compared to every day exposure; for example an X-ray of the arm is 0.001 mSv (millisievert), a dental X-ray is 0.005 mSv, a chest X-ray is 0.020 mSv – in comparison the average background radiation received over one day is 0.010 mSV, while someone flying across the continental USA would receive 0.040 mSV. However, other scans are higher, a mammogram is 0.400 mSv (equivalent of 40 days worth of exposure in one dose), while a head CT scan gives a dose of 2 mSv (equivalent to ~7 months) and a chest CT scan 7 mSv (equivalent to ~20 months) (see the below image from Randall Munroe for more examples).

Although the cells in our body are able to repair and restore DNA damage resulting from radiation, the greater the dose received in one go, and the greater received in the long-term, the more likely it is that damage won’t be repaired correctly. Thus, we should aim to reduce patients’ exposure to radiation where possible. A recent paper by Kitchen and colleagues may have an answer by using phase-contrast x-ray imaging.[1] Because soft tissue has similar X-ray absorption properties to bone, which results in poor image contrast the radiation dosage has to be increased in standard scans. This new technique combines CT scans with phase retrieval and an algorithm to define edges, densities, etc. and results in a reduction in dosage by a factor of 300 fold (with the potential for a reduction factor in the tens of thousands), while still retaining equivalent image quality. Although the study only tested this in an animal model it is an important first step.

092 DCvi - radiation

— Peter Chilton, Research Fellow

Reference:

  1. Kitchen MJ, Buckley GA, Gureyev TE, et al. CT dose reduction factors in the thousands using X-ray phase contrast. Sci Rep. 2017; 7: 15953.

Antioxidants and Age-Related Macular Degeneration

It is estimated that around 5% of the general population suffer from age-related macular degeneration (AMD),[1] where extracellular material known as drusen accumulate under the retina at the back of the eye and which can eventually lead to blurred or a loss of vision. It has been suggested that antioxidants may help prevent or delay development of AMD in people who do not suffer the condition by protecting the retina against oxidative stress, but it is unclear as to whether this is the case.

A systematic review in the Cochrane Database by Evans and Lawrenson looked at the effectiveness of antioxidant supplements as treatment in people who already had AMD,[2] and found that taking a multivitamin antioxidant vitamin may delay the progression of AMD when compared to a placebo or no treatment (odds ratio 0.72, 95% CI 0.58-0.90). The authors also conducted a systematic review looking at whether there was an association between taking antioxidant vitamins (carotenoids, vitamin C, vitamin E) or minerals (selenium, zinc) and the development of AMD in people without AMD.[3] Five RCTs were included, with a total of 76,756 individuals without AMD. These studies all looked at the use of various supplements against placebo. Generally, the various studies found that there was no effect of supplements on development of AMD, while in some cases there was evidence of an increased risk (see table below).

Comparison No. of studies Disease Risk Ratio (95% Confidence Interval)
Vitamin E vs. placebo 4 AMD 0.97 (0.90-1.06)
Late-stage AMD 1.22 (0.89-1.67)
Beta-carotene vs. placebo 2 AMD 1.00 (0.88-1.14)
Late-stage AMD 0.90 (0.65-1.24)
Vitamin C vs. placebo 1 AMD 0.96 (0.79-1.18)
Late-stage AMD 0.94 (0.61-1.46)
Multivitamin vs. placebo 1 AMD 1.21 (1.02-1.43)
Late-stage AMD 1.22 (0.88-1.69)

— Peter Chilton, Research Fellow

References:

  1. Owen CG, Jarrar Z, Wormald R, Cook DG, Fletcher AE, Rudnicka AR. The estimated prevalence and incidence of late stage age related macular degeneration in the UK. Br J Ophthalmol. 2012; 96(5): 752-6.
  2. Evans JR, Lawrenson JG. Antioxidant vitamin and mineral supplements for slowing the progression of age-related macular degeneration. Cochrane Database Sys Rev. 2017; 7: CD000254.
  3. Evans JR, Lawrenson JG. Antioxidant vitamin and mineral supplements for preventing age-related macular degeneration. Cochrane Database Sys Rev. 2017; 7: CD000253.

Diagnosing CTE in Living Patients

Earlier this year our News Blog included a study looking at the brains of former American footballers, which found chronic traumatic encephalopathy (CTE) was present in 110 of 111 footballers who had played in the National Football League (NFL).[1] [2] However, this can only be seen during autopsy, and, at present, we are only able to make a presumptive diagnosis of CTE while the patient is alive. Now a study published in Neurosurgery [3] has found that it may be possible to diagnose CTE in living patients. PET imaging was conducted on the brain of a footballer 52 months prior to this death, and after autopsy, it was found that data from the PET scan (showing the level of binding of a molecular imaging probe) correlated significantly with deposition of tau proteins in the brain (P=0.02). Although this is only a single patient, further investigation is warranted, which could confirm whether PET scanning is a useful diagnostic tool in patients at high-risk of CTE – not only American footballers, but also military personnel.

— Peter Chilton, Research Fellow

References:

  1. Lilford RJ. Two Hundred and Two Ex-(American) Footballers’ Brains Analysed After Death – This You Must Read. NIHR CLAHRC West Midlands News Blog. 15 September 2017.
  2. Mez J, Daneshvar DH, Kiernan PT, et al. Clinopathological Evaluation of Chronic Traumatic Encephalopathy in Players of American Football. JAMA. 2017; 318(4): 360-70.
  3. Omalu B, Small GW, Bailes J, et al. Postmortem Autopsy-Confirmation of Antemortem [F-18]FDDNP-PET Scans in a Football Player With Chronic Traumatic Encephalopathy. 2017.

CBT for OCD

We have spoken before about the merits of cognitive behavioural therapy (CBT) in managing mental health,[1] and a recent study by Højgaard and colleagues looked at its long-term effectiveness for children with obsessive-compulsive disorder (OCD).[2] While previous research has been shown it to be effective, it was not known for how long this effect lasted. In this study of children who responded positively to initial therapy, 121 out of 155 children (78%) were in remission one year after the initial therapy, with an average decrease in CY-BOCS score (an obsessive-compulsive scale specifically for children) of 1.72 points (p=0.001). Although the benefits can be expected to be maintained for at least one year there is still a need to remain aware of OCD symptoms before they re-develop.

— Peter Chilton, Research Fellow

References:

  1. Lilford RJ. Cognitive Behavioural Therapy vs. Mindfulness Therapy. NIHR CLAHRC West Midlands News Blog. 21 July 2017.
  2. Højgaard DRMA, Hybel KA, Ivarsson T, et al. One-Year Outcome for Responders of Cognitive-Behavioral Therapy for Pediatric Obsessive-Compulsive Disorder. J Am Acad Child Adolesc Psychiatr. 2017; 56(11): 940-7.