Wireless homes in the USA and health

A recent Center for Disease Control (CDC) survey found that 25.6 percent of all US households had only a wireless telephone in the last half of 2009, up from 8.6 at the beginning of 2006. [1] The percentage of US households with a mobile phone was 82.7 in the second half of 2009, up from 56.1 in the second half of 2006.

The share of US households with a mobile phone is higher than Canada or Mexico. However a number of countries in the Western Hemisphere have a higher penetration than the US including Colombia and Paraguay. In South Africa, site of the 2010 football World Cup, there are slightly more homes with a mobile phone than the US.

Neither the US Census Bureau nor the Federal Communications Commission compile this data. It may seem strange that the CDC collects these statistics but they need to track what kind of phone respondents have in order to follow-up health surveys. As the CDC notes, telephone based surveys that only query those with a fixed telephone line can produce misleading results:

"The potential for bias due to undercoverage remains a real and growing threat to surveys conducted only on landline telephones...for health-related behaviors, health care service use indicators, and health care access measures, caution is warranted when using landline surveys to draw inferences about subpopulations more likely to be wireless-only (such as young or low-income adults)."

While the CDC carries out surveys on US home telephone ownership, Measure DHS carries out demographic and health surveys on a global basis in many developing nations. As part of the section on household characteristics, there is data on the percentage of homes with a mobile phones.

The CDC and Measure DHS surveys are valuable sources of information for data on household mobile phone penetration. This medical connection for mobile phone statistics is in turn linked to the potential for mobile phones to help health. One m-health application is sending a text message reminding people about their doctor appointment. A study from Imperial College in the UK found that sending an SMS reminder resulted in a 38% reduction in no shows. If more people went to the doctor when they are scheduled to, it could save the UK health system millions: unfulfilled appointments are estimated to waste almost £800 million a year! [2]

While there is significant potential for mobile phones to help health, there is also a fear that they may be harming health. A major study involving some 200,000 mobile phone users over a number of years is being conducted by the same Imperial College mentioned above to see if mobile phones are "...linked to long-term health effects such as brain cancer and neurodegenerative diseases." [3]

[1] Blumberg SJ, Luke JV. "Wireless substitution: Early release of estimates from the National Health Interview Survey, July–December 2009." National Center for Health Statistics. May 2010. Available from: http://www.cdc.gov/nchs/nhis.htm

[2] Koshy, Elizabeth, Josip Car, and Azeem Majeed. 2008. "Effectiveness of mobile-phone short message service (SMS) reminders for ophthalmology outpatient appointments: Observational study." BMC Ophthalmology 8, no. 1: 9. doi:10.1186/1471-2415-8-9. http://www.biomedcentral.com/1471-2415/8/9

[3] Mobile Telecommunications and Health Research Programme. "New Mobile Phone Research Announced." Press Release. June 6, 2008. http://www.mthr.org.uk