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Re: Banning Mobile phones In Hospitals: Is There Enough Evidence?

Dear Editor,

In an otherwise comprehensive review article by Dr.Wood on the health risk of mobile phone usage, there was no mention of the mobile phone usage policies adopted by the hospitals in the UK. Mobile phone use has escalated over the past decade and to many people they are now an essential part of business, commerce and society. According to the Oftel Residential survey, 75 percent of all adults in the United Kingdom owned or used a mobile phone in May 2003 (1). The use of mobile phones and related technologies will continue to increase for the foreseeable future. Many hospitals in the UK ban the use of mobile phones in their premises. It is ironic that in this era of evidence based medicine; there is not much evidence to support this practice. In fact, Medicines and Healthcare products Regulatory Agency (MHRA), the committee to advise the Department of Health on these issues, does not support a blanket ban of mobile phones in hospitals (2). They suggest that individual hospitals should identify the areas where mobile phone usage might interfere with medical equipments. Eg; Intensive therapy units (ITU), Special care baby units (SCBU). Data from MHRA studies (3) showed that only 4% devices suffered interference from cell phones at a distance of 1 metre, with less than 0.1% showing serious effects as compared to the observations that 41% of medical devices suffered interference from emergency radio handsets at a distance of 1 metre with 49% of the responses being serious. MHRA classifies communication devices into three categories:

1. High-risk equipments like private business radios (PBR) mainly used by porters and maintenance staff and analogue emergency service radios.

2. Medium risk equipments like mobile phones, laptop computers and palmtops and gaming devices fitted with GPRS (General Packet Radio System) and,

3.low risk devices like cordless phones (including DECT- Digital European Cordless Technology) (2).

Physiological monitors or devices incorporating them like defibrillators or external pacemakers were the most severely affected devices and for every device type, some models consistently performed better than average. Current policies adopted by most hospitals in UK do not address the issues related to the use of palmtop or laptop computers and more and more health professionals rely on these devices for access to information portals. We think that hospital managements should recognise the fact that so many people own mobile phones attests to their perceived importance to the general public and effort should be made to develop new evidence based policies rather than enforcing a blanket ban of mobile phones so that general public and health professionals can make the optimum use of the mobile technology without compromising patient safety.

Competing interests: Author owns two mobile phones

References:

1.Adult mobile phone ownership or use by age 2001 and 2003; social trends 34 National Statistics Report on mobile phones

2. Mobile communications interference – January 2005 Supplement to Device Bulletin 9702 MHRA.

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Re: Banning Mobile Phones in Hospitals: Is there enough evidence? - response

Dear Editor,

I would like to thank Dr Muhammed for raising the question of whether the practice (in some jurisdictions at least) of a blanket ban on mobile phone or other wireless devices in hospitals is justified. This, of course, arises from indirect effects of radiofrequency emissions, rather than the putative direct effects I reviewed in my article (Wood, 2006). It is of interest to note that the emission limits placed on electronic equipment to avoid interference with other equipment are around 10 times lower than the exposure limits for ensuring that people are appropriately protected. In a recent review article (Lawrentschuk & Bolton 2004) the results of 7 studies on mobile phone interference with hospital equipment were compared, showing around 6% of the 936 items tested having some form of interference deemed clinically relevant. This review also refers to a report of a death due to a respirator being turned off by mobile phone emission. However, if the phone or other wireless device is more than 2 m from the equipment, the incidence of clinically relevant interference is very low, but not, it would appear, zero (Clifford et al 1994). There would be thus some justification in designating some ‘phone and GPRS switch-off’ areas of the hospitals where sensitive life-support equipment is expected to be. Dr Muhammed correctly identifies this as current UK advice via the Medicines and Healthcare products Regulatory Agency (MHRA). The US Food and Drug Administration (FDA), on the other hand, appear to recommend the devolvement of the management of the interference issue to local hospital experts. The ‘2 m rule’ used in some jurisdictions, seems to me to be impracticable, because of the difficulty of knowing, especially when replying to a mobile phone call, how far away particular equipment is. The trend to lower transmit powers in modern devices may imply that 2 m is overly conservative, since the Clifford et al. data are now over 20 years old. I would agree with Dr Muhammed that there has been relatively less testing involving other wireless sources such as GPRS and 3G HIPERLANS, however again, these may well turn out to be less capable of causing interference because of the higher frequencies, lower transmit powers and different modulation schemes involved.

References:

Clifford KJ, Joyner KH, Stroud DB, Wood M, Ward B, Fernandez CH. 1994. Mobile telephones interfere with medical electrical equipment. Australas Phys Eng Sci Med; 17:23-7

Lawrentschuk N, Bolton DM. 2004. Mobile phone interference with medical equipment and its clinical relevance: a systematic review. Med J Aust; 181:145-9

Wood AW. 2006. How dangerous are mobile phones, transmission masts, and electricity pylons? Arch Dis Child 2006; 91: 361-366

MHRA: FAQ on the use of mobile phones in hopsital :http://www.mhra.gov.uk/home/idcplg?IdcService=SS_GET_PAGE&useSecondary=true&ssDocName=CON2023751