Mobile phones and healthcare improvement
I remember as a medical student how averse to mobile phones the hospital environment was, particularly around patients on cardiac monitors, and even in hospital corridors. Thankfully, most hospitals are more sensible in their approach these days; allowing relatives and patients to use their phones in most hospital areas at a time when communication is very important to them.
Most of the fear around health risks posed by mobile phones has focussed on cancer. A major review of existing studies showed that mobile phone use led to “no increased risk within approximately 10 years of use for any tumor of the brain or any other head tumor”. This data is particularly strong for fast-growing tumors (e.g. malignant glioma). On the other hand, for slow-growing tumors (e.g. meningioma and acoustic neuroma), the observation periods of mobile phone use within studies have been too short. Similarly, a case-control study published this year in the BMJ showed no association between risk of early childhood cancers and maternal exposure to mobile phone base stations during pregnancy.
It turns out that mobile phones are of great interest to medical researchers: 2602 hits in Pubmed to-date with 160 review articles. For over 10 years, the potential of telemedicine and mobile phones as a force for good in healthcare has been explored. The benefits of mobile phone usage in disease management programmes have been found across many diseases, from reducing frequency and duration of heart failure hospitalisations and self-monitoring of glucose in diabetes to obesity and hypertension.
A systematic review titled, “Healthcare via cell phones identified 25 studies that evaluated cell phone voice and text messaging interventions, with 20 randomized controlled trials and 5 controlled studies. “Frequency of message delivery ranged from 5 times per day for diabetes and smoking cessation support to once a week for advice on how to overcome barriers and maintain regular physical activity. Significant improvements were noted in compliance with medicine taking, asthma symptoms, HbA1C, stress levels, smoking quit rates, and self-efficacy, …….with implications for both patients and providers.”
As bluetooth technology improves to allow remote assessment of patients, particularly in blood pressure monitoring, it seems that mobile phones may represent one of those rare technological advances that can also be useful in low resource settings. The Lancet Online published the results of a randomised controlled trial from Kenya today showing that mobile phone communication between health-care workers and patients starting antiretroviral therapy improves adherence to therapy. 538 clinic patients starting antiretrovirals were randomised to either receive weekly SMS messages from a clinic nurse or to standard care with impressive NNTs. To achieve greater than 95% adherence, only 9 patients needed to receive SMS messages, and to achieve suppression of the viral load of HIV only 11 patients needed to get SMS reminders. The (SMS) message is very clear. Health professionals have to stay afloat of technology and use all available tools to improve healthcare outcomes, maybe even more so in resource-poor settings.
The evidence-base suggests mobile phone masts don't cause childhood cancer
In the BMJ this week is a case control study on Mobile phone base stations and early childhood cancers. A case control study is an epidemiological study design in which persons with and without a disease, in this case cancer, are studied to identify factors (mobile phone masts) associated with the disease. The gold standard would be a prospective study (not a trial as this would be unethical); however, when the disease is rare it is too difficult, costly and would involve following millions of children to detect the cases.
Concerns has been raised due to there being a few clusters of cancers in people living nearby to mobile masts. Participants in a survey were concerned about or attributed adverse health effects to mobile phone base stations and those living within 500 m reported slightly more health complaints than others.
In the present study for two years (1999 to 2001) researchers obtained data on all registered cases of cancer in children aged 0 to 4 in Great Britain. From 1,926 cases, 1,397 (73%) were included. Four controls per case were obtained and matched by sex and date of birth.
Further to this mobile phone operators provided data on antennas to an accuracy of about 10m and the researchers estimated exposure in relation to the distance and the total power output across base stations within 700 m (the typical peak is not nearest the mast, but normally is 200 to 500 m from the base station). They also and used a model to compute power density (dBm) which was validated with data from two further surveys.
The results of the study showed the mean age at diagnosis of cancer was two years and the mean distance at birth from a base station was not different between the cases, 1107 m and the controls, 1073 m (P=0.31). Also there was no difference in terms of the mean total power output of base stations within 700 m (P=0.54) for both groups; and no difference in the mean modelled power density (P=0.41).
The evidence presented in this paper for lack of effect is backed up by the dramatic increase in the use of mobile telephones not giving rise to a subsequent increase in the incidence of brain tumours. The one major limitation of this study is that they were unable to account for movement of the mother during pregnancy, which could have reduced the ability of the study to detect any true excess in risk.
Overall this is a well done study and allows us to feel more certain about the evidence base that there is no association between risk of cancer in young children and exposure to mobile phone base stations. It seems we can all relax a little more about mobile phone masts, the radiofrequency exposures are extremely low and backs up the World Health Organization, view that cancer is unlikely to be caused by cellular phones or their base stations.
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