May 2009 – Helen Jaques

Cancer survivor detained by US immigration because treatment eradicated fingerprints

May 27, 2009 No Comments

A 62-year-old cancer survivor was recently temporarily denied entry into the US because the treatment he had been receiving had wiped out his fingerprints.

The patient, Mr S, had been taking the chemotherapy drug capecitabine for three years to prevent recurrence of his nasopharyngeal cancer following successful treatment of the disease with another chemotherapy regimen.

Capecitabine can cause inflammation, peeling, bleeding and blistering of the palms of the hands and soles of the feet, a side effect known as plantar-palmar syndrome. Interestingly, survival is significantly better in patients on capecitabine who experience this severe plantar-palmar syndrome.

The case report of Mr S, published in Annals of Oncology, states that the patient had grade 2 plantar-palmar syndrome that did not affect his daily activities and function. He was not aware that he had lost his fingerprints when he set off from Singapore to visit relatives in the US.

According to the case report, Mr S “was detained at the airport customs for four hours because the immigration officers could not detect his fingerprints. He was allowed to enter after the custom officers were satisfied that he was not a security threat”.

The patient’s oncologist Dr Eng-Huat Tan, senior consultant at Singapore’s National Cancer Center, advises that all patients who are receiving capecitabine carry a doctor’s letter with them when they travel, as doctors are not sure which patients on the drug will lose their fingerprints or when in the course of treatment this will occur.

“Patients taking long-term capecitabine may have problems with regards to fingerprint identification when they enter United States’ ports or other countries that require fingerprint identification and should be warned about this”, writes Dr Tan. “There may be a growing number of such patients as Mr S who may benefit from maintenance capecitabine for disseminated malignancy. These patients should prepare adequately before travelling to avert the inconvenience that Mr S was put through.”

International airports in the US have been fingerprinting foreign visitors since 2004 under the US-Visit (US Visitor and Immigrant Status Indicator Technology) security system. At least two index fingerprint images are taken from all foreign visitors, including those from countries in the visa waiver scheme such as the UK, which are matched with millions of records to detect whether the visitor is attempting to use fradulent identification. These fingerprints are also matched to a list of known or suspected terrorists, criminals and immigration violators.

Public health, Technology

A new way of visualising health data

May 20, 2009 No Comments

Are smokers more likely to be obese? Is stroke more common in people with hypertension? Are old people more likely to have diabetes than young people?

The prospect of trawling through the scientific literature to get the answers to these questions isn’t terribly appealing – reams of tables and risk ratios aren’t helpful if you just want the information at a glance. Technology and health care company GE have developed a new way to present complex epidemiology data in graphic form.

Taking a New Look at Health allows you to compare various demographics, risk factors and diseases in a random sample of 100,000 patient records from GE’s proprietary database. Once you’ve picked the two variables you want to look at, legions of tiny men shoot across the graphic and align to show what proportion of people with variable also have variable y.

In this example, I have looked at smoking and BMI to see whether smokers are more likely to be obese than are non-smokers:

smoking-vs-obesity

Given that the figures are presented as an image rather than a table of numbers, it’s much easier to get a handle on the proportions and what they really mean. I can now see at a glance that actually more non-smokers and ex-smokers than smokers are obese (28%, 29% and 27%, respectively); that is, smokers are less likely to be obese.

Here are a couple more examples:

Is stroke more common in people with hypertension?

hypertension-vs-stroke

As well as showing that people with hypertension are considerably more likely to experience a stroke than those without hypertension (5% vs 1%), this particular graphic also allows us to see roughly what the incidence of hypertension is in the GE sample – not huge judging by the slim column on the right hand side.

Are old people more likely to have diabetes than young people?

age-vs-diabetes

Yup, look how many little orange people there are in the 65-74 column and the 75+ column!

Why not have a play with the visualisation yourself? Is the link between heart disease and hypertension what you expect? And what was the male:female ratio in this sample anyway? If you like epidemiology you’ll probably have a lot of fun!

Arts, Physiology

Every-body loves anatomy

May 4, 2009 No Comments

I thought it was finally about time I wrote a post about the fantastic Street Anatomy blog. Billing itself as ‘obsessively covering the use of human anatomy in medicine, art and design’, the site highlights tons of interesting uses of human anatomy in everything from fashion to advertising.

Although a lot of the art the blog features is amazing – photography, jewelery and album covers to name a few examples – I’m most intrigued by all the wacky products they pick out, the perfect present for any medically minded friend!

Med student cousin sweating about an anatomy exam? Give him a sneaky solution by getting him the answers on a t-shirt!

Girlfriend stamped all over your heart? You can do the same to her, albeit a bit more literally, with these trainers.

Does your little sister want to be a doctor when she grows up? A anatomical My Little Pony will give her a headstart!

If it’s my birthday you’re shopping for though, I want some anatomical bed sheets. Or one of these please.

Surgery, Transplantation

What makes relatives agree to organ donation?

May 1, 2009 No Comments

donor-card The BMJ has just published an interesting paper on the factors that determine whether family agree to donate the organs of a brain dead relative.

According to the meta-analysis by researchers at the University of Oxford, careful timing and having a transplant coordinator make the request are key factors in whether relatives consent to organ donation.

This time last year, more than 7,500 people in the UK were listed as actively waiting for a transplant. The biggest barrier to living organ donation is refusal of consent by the relatives of the donor. A 2006 audit of all deaths in nearly 350 intensive care units around the UK found that as many as 41% of relatives refused to allow organ donation.

The authors of the BMJ study analysed 20 observational studies and audits, and identified the following six categories of modifiable factors that apparently influence relatives’ decisions to allow organ donation:

Information discussed during the request
Perceived quality of care of the donor
Understanding of brain stem death
Specific timing of the request
Setting in which the request is made
Approach and expertise of the individual making the request

The most important factor, quite understandably, was whether the request for donation occurred at the same time as the notification of death or testing for brain stem death. In addition, medical professionals are involved with the request process had a considerable effect on consent rates – a combined approach by hospital staff and coordinators from an organ procurement organisation improved consent, as did the use of race-specific requestors and a dose of common courtesy.

Unsurprisingly, there was a correlation between staff training in organ donation request and donation rates. In fact, the consent rate differed throughout the year in accordance with the training programmes of medical residents.

The fact that the authors of this study were looking at modifiable factors is important – it’s no good looking at whether factors like religion influence the likelihood of relatives consenting to donation as doctors can’t influence such beliefs. In order to increase the number of people agreeing to donation researchers need to identify elements of the decision making that they can have an effect on.

Targeting these modifiable factors could have a huge effect donation rates and could save lives. The authors point out that “organ donation may be of sufficient benefit to society generally, and to organ recipients specifically, to justify the study and modification of organ donation requests to maximize consent”.

Let’s hope that doctors and hospitals take this information on board and start to approach the families of potential donors with a renewed appreciation of the delicacy of the task.

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Simpkin A et al. (2009) Modifiable factors influencing relatives’ decision to offer organ donation: systematic review. BMJ 21 April 2009 DOI: 10.1136/bmj.b991