cancer-related deaths in 2012. It estimated that the number of cases could increase by 70% through 2032. As the number of cancer patients receiving treatment increases, hospitals around the world are seeking ways to improve patient safety, to emphasize traceability and raise efficiency in their cancer treatment processes. Difficulties in measuring frequency of errors About 1% of hospital admissions result in an adverse event due to negligence. However, mistakes are likely much more common, as these studies identify only mistakes that led to measurable adverse events occurring soon after the errors. Independent review of doctors' treatment plans suggests that decision-making could be improved in 14% of admissions; many of the benefits would have delayed manifestations. Even this number may be an underestimate. One study suggests that adults in the United States receive only 55% of recommended care. At the same time, a second study found that 30% of care in the United States may be unnecessary. For example, if a doctor fails to order a mammogram that is past due, this mistake will not show up in the first type of study. In addition, because no adverse event occurred during the short follow-up of the study, the mistake also would not show up in the second type of study because only the principal treatment plans were critiqued. However, the mistake would be recorded in the third type of study. If a doctor recommends an unnecessary treatment or test, it may not show in any of these types of studies. Cause of death on United States death certificates, statistically compiled by the Centers for Disease Control and Prevention (CDC), are coded in the International Classification of Disease (ICD), which does not include codes for human and system factors. Causes The research literature showed that medical errors are caused by errors of commission and errors of omission. Errors of omission are made when providers did not take action when they should have, while errors of commission occur when decisions and action are delayed. Commission and omission errors have also been attributed with communication failures. Medical errors can be associated with inexperienced physicians and nurses, new procedures, extremes of age, and complex or urgent care. Poor communication (whether in one's own language or, as may be the case for medical tourists, another language), improper documentation, illegible handwriting, spelling errors, inadequate nurse-to-patient ratios, and similarly named medications are also known to contribute to the