29 Oct, 10 | by BMJ Group
“Research highlights” is a weekly round-up of research papers appearing in the print BMJ. We start off with this week’s research questions, before providing more detail on some individual research papers and accompanying articles.
- Does offering antenatal screening for sickle cell disease and thalassaemia in primary care facilitate earlier uptake of screening?
- How does high flow oxygen affect mortality in people with acute exacerbation of chronic obstructive pulmonary disease, compared with titrated oxygen?
- In people receiving opioid substitution treatment, does drug related mortality vary according to duration of treatment?
- Is China’s new cooperative medical scheme for rural citizens associated with changes in operation and use of village health clinics?
Antenatal screening for haemoglobinopathies
Pregnant women in England should be offered screening for haemoglobinopathies like sickle cell disease and thalassaemia early in gestation so that those with a positive result have the time to make an informed decision about their options, which might include termination. However, only 4.4% of women receive antenatal screening by 10 weeks’ gestation, the crucial cut off to enable prenatal diagnostic testing by 13 weeks.
Elizabeth Dormandy and colleagues have found that offering screening when women present to their general practitioner for confirmation of their pregnancy does help improve this rate, but not by much. Women offered screening by their GP were 17-28% more likely to have been tested by 10 weeks’ gestation than women offered screening by a midwife, but the absolute rates of uptake were only 24-28% in the GP groups and 2% in the midwife group.
Writing in an editorial about the research, general practitioner Judy Shakespeare suggests that by not offering screening early in gestation she and her peers “are failing women with affected pregnancies, who cannot make reproductive choices if professionals ‘miss the boat,’” and calls on her colleagues to “take responsibility for testing.”
High flow oxygen in COPD
Whether or not to give patients with acute exacerbations of chronic obstructive pulmonary disease (COPD) high flow oxygen is controversial. Although some paramedics call concern about this practice “fear mongering,” British Thoracic Society guidelines recommend controlled rather than high flow oxygen in this situation (Thorax 2008;63(suppl 6):vi1-68).
Michael Austin and colleagues’ study on this approach in 405 patients with presumed acute exacerbation of COPD treated by paramedics in Tasmania, Australia, provides more evidence for the “against” side. Patients on high flow oxygen had higher mortality than those on titrated oxygen, both overall and in the group with confirmed COPD.
Editorialists B Ronan O’Driscoll and Richard Beasley write that this study “provides robust evidence that the routine administration of high concentration oxygen in acute exacerbations of COPD is associated with increased mortality.” On the other hand, American blogger and retired paramedic Michael Coston points to the shortcomings in the study and suggests it doesn’t resolve the issue of which approach to use. He argues: “It is, after all, counterintuitive to deprive someone who is in serious respiratory distress abundant oxygen.” Perhaps this controversy is set to simmer for a while longer yet.
Earlier this year we published an observational study by Jo Kimber and colleagues showing that longer duration of opioid substitution treatment was associated with reduced mortality, but also with a lower likelihood of long term injection cessation. An online rapid response praised the analysis for “highlighting that opioid addiction is well known to be a chronic disorder, for which most of our information is only short term.” The study had limitations, however, including that it was based on data from a single primary care facility in Edinburgh.
Now a group including some of the same authors extends its research nationwide in an analysis of data from the UK General Practice Research Database, to investigate changes in risk of death over the duration of substitution treatment. Rosie Cornish and colleagues found that mortality was increased at the start of treatment and immediately after treatment stopped, indicating that a potential reduction in drug related mortality occurs at treatment durations around or above a year.
In an editorial accompanying the earlier paper Evan Wood called for evidence based policy surrounding illicit drugs. But shortly afterwards, addiction specialists warned that a recommendation from England’s National Treatment Agency for Substance Misuse to limit the length of time that methadone can be prescribed in the community was not based on evidence and would do more harm than good (doi:10.1136/bmj.c3998). In this politically controversial field, the more evidence the better. On the practice level, UK doctors who are cautious about recommending substitution treatment may be reassured to hear that the evidence for such therapy holds true in their particular setting.
Research online: For these and other new research articles see www.bmj.com/research
Medical care in rural China
A podcast accompanies the publication of Kimberly Singer Babiarz and colleagues’ research on China’s New Rural Cooperative Medical Scheme—which aims to provide health insurance to 800 million rural citizens and to correct distortions in rural primary care—and its effect on the operation and use of village health clinics. We speak to Scott Rozelle from Stanford University and Qingyue Meng, professor and executive director of the China Center for Health Development Studies at Peking University, who explain the background to the formation of the new scheme and its place in the wider Chinese medical system.