What’s being served up in the Cochrane Library?

The reviews are flying into the Cochrane Library quicker than balls off Murray’s racquet this week and several aces have been served! Here’s my pick of the past fortnight.

It’s all strawberries and Pimms in SW19 but in WC1 the good folk of the Cochrane Heart Group are concentrating on garlic sandwiches and tea. Now I like a nice cuppa but a garlic sandwich? Even Jamie Oliver might balk at that, but the suggestion crops up in a new review on preventing cardiovascular disease (CVD) through providing fruit and vegetables to encourage people to eat more of them, or just advising them to do so. I asked heart doctor Harry Boardman to take a look.  He didn’t buy into the garlic idea either and pointed out that the interventions, which often included a single fruit or vegetable, weren’t realistic for widespread adoption by the general public. He also noted that the included trials were generally small and with short follow-up periods. He’d like to see a more varied intervention

fruit and veg in heart shape

Promoting heart health with fruit and veg

trialed soon, especially as there seemed to be some benefit in terms of risk factors for CVD such as blood pressure and LDL-cholesterol. Incidentally, a Cochrane review published last year looked at garlic to reduce the risk of cardiac events and death in people with high blood pressure and found just one trial; too little evidence to be able to say if it’s effective.

How about drinking green or black tea to lower your risk of cardiovascular disease? This was the subject of another new review from the Heart Group. Eleven trials with 821 people were included and the evidence suggests that both types of tea have favourable effects on the aforementioned risk factors, such as LDL-cholesterol and blood pressure. So what did Harry think of this one? He commented: “unfortunately the trials were small with relatively short follow-up and several used tea extract tablets, which are less applicable to a general population drinking tea. However it gives some encouraging data that tea might benefit surrogate cardiovascular endpoints in a palatable form. A larger trial with hard endpoints showing benefit could persuade that tea could join the Mediterranean menu on the dinner table. Anyone for a cuppa?”

While we’re on the subject of food and drink, there’s an excellent new round-up of evidence on so-called ‘superfoods’ from NHS Choices, with lots of lovely Cochrane evidence cited. You can find that here.

pills

Which drugs work best for pain after surgery?

Now, when you have surgery you generally have pain afterwards, right? The Cochrane Pain, Palliative and Supportive Care Group has taken pity on us all in doing a series of reviews looking at which medicines work best and at what dose. The latest one looks at single dose ibuprofen plus paracetomol (acetominophen) and found three suitable trials with 1647 people with moderate or severe pain after having wisdom teeth taken out. The combination of ibuprofen and paracetomol gave better pain relief and for longer than either drug alone (at the same dose) and with fewer side effects. It’s a shame there weren’t more and bigger studies, but on the plus side the included studies were judged to be good quality and generally at low risk of bias. A sister review has also just been published, which showed that the combination of ibuprofen 400 mg + oxycodone 5 mg is better for acute postoperative pain than either drug alone and gave pain relief for longer. The results of the 35 reviews on painkillers for post-operative pain have been brought together in an overview here.

Earlier in the week I blogged about a new Cochrane review on interferon for high-risk melanoma (you can find that here). At the other end of the disease spectrum, Bowen’s disease is a precancerous skin lesion which tends to grow slowly and respond well to treatment. The Cochrane Skin Group has just published a new review which aimed to identify the most effective interventions for cutaneous Bowen’s disease with the fewest side-effects. There was limited evidence (nine studies with 363 people) and most related to photodynamic therapy (PDT), while surgery is the most common treatment and creams are cheaper and more widely used than PDT. This review is less helpful than we’d wish, then, for the general practitioner or dermatologist without access to PDT, as the reviewers point out. Photodynamic therapy appears to be an effective and safe non-scarring treatment. Limited data suggest that 5-fluorouracil is as effective as PDT, that cryotherapy is possibly less effective than PDT, and that imiquimod is also effective.

A review on dehumidifiers for chronic asthma has been updated and it’s a pity that the evidence remains very scanty, with just one trial to add to the only suitable trial found when the review was first published. The trials, both conducted in the UK, investigated the effectiveness of dehumidifiers in the homes of people with asthma who were sensitive to house dust mites. Neither showed  any difference in morning peak flow, which was the main outcome of interest. The only improvement found in the new trial was in evening peak flow. The reviewers note that the results from this one, high-quality trial “leave considerable uncertainty about dehumidifiers in the UK. The results cannot be generalised to hot climatic conditions where similar trials may be needed.”

IV drip attached to woman's hand

No good evidence to support routine use of IV fluids in labour

Finally, I was interested to see a new review on intravenous fluids for reducing the duration of labour in women having a first baby and rather struck by the opening sentence of the accompanying Cochrane Summary, which says “Labour may be considered to be a prolonged period of exercise.” I’ve never thought about it like that! It goes on to point out that women may become dehydrated as a result of their exertions and that in many places they are allowed only a little or no fluid by mouth during labour and are given fluid though a drip (intravenously). This review has a lengthy discussion section to which I’d direct those of you interested in the detail. Despite the inclusion of nine trials with over 1600 women, each outcome drew on results from very few studies (often only one or two), the quality was variable and results often difficult to interpret. In women who were not freely drinking fluids, giving intravenous fluids shortened labour, but this review does not provide robust evidence to support routine administration of intravenous fluids. The safety for mother and baby of giving different types of intravenous fluid has not been rigorously evaluated and none of the trials reported on outcomes such as the women’s comfort or satisfaction associated with being attached to a drip during labour nor even an assessment of their thrist. The reviewers suggest that a policy of restricting drinking needs to be urgently reviewed.

Check back in a fortnight for another round-up; I know there’s some good stuff coming any day now!

Links:

Hartley L, Igbinedion E, Holmes J, Flowers N, Thorogood M, Clarke A, Stranges S, Hooper L, Rees K. Increased consumption of fruit and vegetables for the primary prevention of cardiovascular diseases. Cochrane Database of Systematic Reviews 2013, Issue 6. Art. No.: CD009874. DOI: 10.1002/14651858.CD009874.pub2.

Cochrane summary http://summaries.cochrane.org/CD009874/increased-fruit-and-vegetable-intake-to-prevent-cardiovascular-disease

Stabler SN, Tejani AM, Huynh F, Fowkes C. Garlic for the prevention of cardiovascular morbidity and mortality in hypertensive patients. Cochrane Database of Systematic Reviews 2012, Issue 8. Art. No.: CD007653. DOI: 10.1002/14651858.CD007653.pub2.

Cochrane summary and podcast http://summaries.cochrane.org/CD007653/garlic-for-hypertension

Hartley L, Flowers N, Holmes J, Clarke A, Stranges S, Hooper L, Rees K. Green and black tea for the primary prevention of cardiovascular disease. Cochrane Database of Systematic Reviews 2013, Issue 6. Art. No.: CD009934. DOI: 10.1002/14651858.CD009934.pub2.

Cochrane summary http://summaries.cochrane.org/CD009934/green-and-black-tea-to-prevent-cardiovascular-disease

NHS Choices. Superfoods: the evidence. 

Derry CJ, Derry S, Moore RA. Single dose oral ibuprofen plus paracetamol (acetaminophen) for acute postoperative pain. Cochrane Database of Systematic Reviews 2013, Issue 6. Art. No.: CD010210. DOI: 10.1002/14651858.CD010210.pub2.

Cochrane summary http://summaries.cochrane.org/CD010210/single-dose-oral-ibuprofen-plus-paracetamol-acetaminophen-for-acute-postoperative-pain

Moore RA, Derry S, McQuay HJ, Wiffen PJ. Single dose oral analgesics for acute postoperative pain in adults. Cochrane Database of Systematic Reviews 2011, Issue 9. Art. No.: CD008659. DOI: 10.1002/14651858.CD008659.pub2.

Derry S, Derry CJ, Moore RA. Single dose oral ibuprofen plus oxycodone for acute postoperative pain in adults. Cochrane Database of Systematic Reviews 2013, Issue 6. Art. No.: CD010289. DOI: 10.1002/14651858.CD010289.pub2.

Cochrane summary http://summaries.cochrane.org/CD010289/single-dose-oral-ibuprofen-plus-oxycodone-for-acute-postoperative-pain

Bath-Hextall FJ, Matin RN, Wilkinson D, Leonardi-Bee J. Interventions for cutaneous Bowen’s disease. Cochrane Database of Systematic Reviews 2013, Issue 6. Art. No.: CD007281. DOI: 10.1002/14651858.CD007281.pub2.

Cochrane summary http://summaries.cochrane.org/CD007281/treatments-for-cutaneous-bowens-disease

Singh M, Jaiswal N. Dehumidifiers for chronic asthma. Cochrane Database of Systematic Reviews 2013, Issue 6. Art. No.: CD003563. DOI: 10.1002/14651858.CD003563.pub2.

Dawood F, Dowswell T, Quenby S. Intravenous fluids for reducing the duration of labour in low risk nulliparous women. Cochrane Database of Systematic Reviews 2013, Issue 6. Art. No.: CD007715. DOI: 10.1002/14651858.CD007715.pub2.

Cochrane summary http://summaries.cochrane.org/CD007715/intravenous-fluids-for-preventing-prolonged-labour-in-women-giving-birth-to-their-first-baby

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