What impact can mobile phones have on their users' health? Many individuals are concerned about the supposed ill effects caused by radiation from handsets and base stations,【C1】______ the lack of credible evidence of any harm. But evidence for the beneficial effects of mobile phones on health is rather more【C2】______ Indeed, a systematic review【C3】______ by Rifat Atun and his colleagues at Imperial College, London , gathers【C4】______ of the use of text-messaging in the 【C5】______ of health care. These uses【C6】______ three categories: efficiency gains; public-health gains; and direct benefits to patients by【C7】______ text-messaging into treatment regimes. Using texting to【C8】______ efficiency is not profound science, but big savings can be achieved. Several【C9】______ carried out in England have found that the use of text-messaging reminders【C10】______ the number of missed appointments with family doctors by 26-39% , and the number of missed hospital appointments by 33-50%. If such schemes were【C11】______ nationally, this would translate【C12】______ annual savings of ￡256-364 million. Text messages can also be a good way to deliver public-health information, particularly to groups【C13】______ are hard to reach by other means. Text messages have been used in India to【C14】______ people about the World Health Organization's strategy to control tuberculosis(肺结核) . In Iraq, text messages were used to support a【C15】______ to immunize nearly 5 million children【C16】______ polio(小儿麻痹症). 【C17】______ , there are the uses of text-messaging as part of a treatment regime. These involve sending reminders to patients to【C18】______ their medicine, or to encourage compliance with exercise regimes or efforts to stop smoking. However, Dr. Rifat notes that the evidence for the effectiveness of such schemes is generally【C19】______ . More quantitative research is【C20】______ —which is why his team also published three papers this week looking at the use of mobile phones in health care in more detail.