Alex Nowbar’s weekly journal review—14 February 2020

Alex Nowbar reviews the latest research from the top medical journals.


H pylori and prevention of gastric cancer

I would classify cancer prevention as a medical holy grail. Knowledge of risk factors is a very early stage in that journey. In the case of gastric cancer, Helicobacter pylori infection and a family history of gastric cancer are the main risk factors. The hypothesis tested in this large, double blind, randomised Korean trial was that H pylori eradication would reduce the risk of gastric cancer in people with a family history of an affected first degree relative. And it did over a median follow-up of nine years. The hazard ratio for the protective effect of seven days of triple therapy with lansoprazole, amoxicillin, and clarithromycin was 0.45. This is overwhelming evidence in support of H pylori eradication in people with a family history of gastric cancer in a first degree relative despite higher rates of adverse effects (especially diarrhoea and taste alteration) in the treatment group.

Primary care in the US

The US healthcare system has both much to be admired and leaves much to be desired. In the “to be desired” zone is their relationship with primary care. The premise is that primary care use is good for improving outcomes and reducing costs although even that is not concrete because comparisons are usually against specialist care rather than alternative sources of care. Ganguli et al studied use of primary care in adults aged 18 to 64 with one large US insurer between 2008 and 2016. During this period there was a 24% reduction in the number of primary care visits per person per year while visit rates to specialists remained the same. However, visits to alternative venues such as urgent care increased by 47%. There is no way of knowing exactly why the patterns have changed, but this study assessed a number of possible contributing factors such as a rise in out-of-pocket costs per visit and use of alternative sources of care. The declines in primary care use were greatest in young adults. Have they started to need less care? Of course not, they are just accessing care in other ways.


Risk of suicide with neurological disorders

Erlangsen et al looked at the risk of death by suicide in 7 million people in Denmark between 1980 and 2016. They found that people diagnosed with a neurological disorder had a higher rate of suicide than those who were not diagnosed with one. The neurological disorders with the most strikingly high risk were the ones you might expect: Huntington disease and motor neurone disease (specifically amyotrophic lateral sclerosis). The authors suggest that this is in keeping with other life-threatening conditions being associated with higher risk of suicide such as pancreatic cancer. Stroke, head injury, Parkinson disease, CNS infection, multiple sclerosis and epilepsy (and in fact almost every neurological condition they assessed except Alzheimers and muscular dystrophy which had a lower risk) were all associated with higher suicide risk than not being diagnosed with a neurological disorder, but not to the same extent. Even though the absolute risk increase was small for all the neurological disorders, the findings are worthy of recognition. Neurological disorders may have an impact on mental health pathologically or (more likely given the heterogeneity of the conditions implicated) the suicide rates may merely be a byproduct of having serious, life-altering chronic conditions. Either way, increased focus on mental health in neurological disorders is a good idea.

Bilevel positive airway pressure at home

Home use of bilevel positive airway pressure is common for patients with chronic obstructive pulmonary disease and hypercapnia, but is there any evidence of benefit in randomised controlled trials? Wilson et al’s meta-analysis (of randomised controlled trials and observational studies lumped together unfortunately) finally sheds some light on this. They found that, compared with no device, bilevel positive airway pressure was associated with a lower risk of death and fewer hospital admissions. There was also a lower risk of needing intubation, but let’s ignore this outcome because the decision to intubate isn’t a good marker of anything, particularly in unblinded studies. In fact, even hospital admissions aren’t good markers of benefit when patients and staff are unblinded to whether the patient is receiving the device. The most interesting finding in this analysis is the lack of benefit on quality of life, although, given the prognostic benefit, I suspect this will fade into insignificance.


Lofty goals in cervical cancer

Cervical cancer causes a lot of deaths, especially in lower income countries, so is a priority for the WHO. They developed the 90-70-90 triple intervention strategy for 2030. The first 90% target is for human papillomavirus (HPV) vaccination coverage. The 70% is coverage of twice in a lifetime screening with HPV testing, and the final 90% is for women to have access to precancer and cancer treatment and palliative care services. Canfell et al modelled the impact of this strategy on cervical cancer mortality. They predict a one third reduction in the rate of premature mortality from cervical cancer in low to middle income countries in the next 10 years. They project that cervical cancer could be eliminated by 2130. These results support the 90-70-90 strategy, but how this will be achieved isn’t entirely clear yet.

JAMA Internal Medicine

Thromoboprophylactic swing

Post-operative venous thromboembolism is the bane of knee and hip operations. Anticoagulation is the mainstay of prevention, but could aspirin be enough? Not that aspirin is without risk, but it has several advantages over anticoagulation. Matharu’s meta-analysis of 13 randomised controlled trials encompassing over 6000 patients set out to answer this important question. They found no difference in rates of deep veoin thrombosis, pulmonary embolism, major bleeding, or wound haematoma between aspirin and anticoagulants (including low molecular weight heparin and rivaroxaban). So we’ve swung from no prophylaxis to aggressive prophylaxis and now to the middle ground of aspirin. One downside of this study is the quality and content of the trials included in the meta-analysis such as selective adverse event reporting and drug dosage and duration.

Dietary dalliances

Zhong et al’s large US cohort study looked at the association between consumption of red meat, poultry, and fish and cardiovascular disease and all-cause death in nearly 30 000 US adults. If this sounds familiar, that’s because it is. But this analysis takes a look at processed versus unprocessed red meat. They found an increase in cardiovascular disease and deaths in both people with a high intake of unprocessed red meat and in people with high intake of processed red meat (a strong association statistically but without a hugely elevated risk). This calls into question the prevailing belief that processed red meat is the worst kind of meat one can consume. Fish intake was not associated with cardiovascular disease or death. Interestingly poultry was associated with cardiovascular disease incidence but not all-cause death. A strength of this analysis is the length of follow-up, which was a median of 19 years. 

Alex Nowbar is a clinical research fellow at Imperial College London

Competing interests: None declared