WASHINGTON — Oct. 1, 2013, might mean little to most clinicians now, just a day somewhere between Labor Day and Halloween in about two years.

This time next year, however, healthcare providers are likely to have the day circled on their calendars – in red.

It is the date that healthcare systems across the nation will switch from ICD-9 coding to ICD-10, and the learning curve is steep.

For many healthcare systems — those which involve only a handful of facilities and only have to coordinate with their insurers and Medicare — the process may be relatively straightforward. For VA, which consists of thousands of physicians in hundreds of facilities nationwide, that process will be considerably more difficult, especially because clinicians must be trained to use more than 19 times the number of codes in the current system.

A Better System

In fact, the changeover process at VA has been under way for some time behind the scenes and off the radar of most physicians who in the coming months will be tasked with relearning an entirely new coding system for medical diagnoses and inpatient procedures.

A country-specific version of the ninth revision of the International Statistical Classification of Diseases and Related Health Problems (ICD-9) system has been in place in the United States since 1983. It provides codes to classify diseases, as well as signs, symptoms, health complaints and patient circumstances. Using the ICD system, physicians can describe a patient’s problems in the form of a six-digit code.

The ICD-9 system was created by the World Health Organization in 1975 but not adopted by and adapted for the United States until eight years later. By that time, WHO was beginning work on the next version of the coding system (ICD-10) in 1983. ICD-10 was completed in 1990, and the current version began being used by most WHO member countries in 1994. Currently, 138 countries use it to track mortality data, and 99 countries use it to track patient diseases.

The United States is now adopting the current system, with the alpha draft of ICD-11 already available on the WHO website. For the first time, WHO is using a collaborative, Web 2.0 approach for a major revision, so changes are made in the draft version daily. The beta version of ICD-11 is expected to be available in May 2012, and the final version to be presented to the World Health Assembly in May 2015.

ICD-10 is already a more advanced system. Where ICD-9 allows for about 14,000 diagnostic codes, ICD-10 allows for more than 70,000. It will also allow for much more detail. For example, in body systems that are paired, such as ears, the system will note whether it is a right ear or left ear condition.

The impact on inpatient-procedure coding will be even more dramatic. The ICD-9 system allows for about 3,800 codes. The ICD-10 system allows for 73,000.

According to those overseeing the changeover in the United States, medicine has thoroughly outpaced the ICD-9 system over the last three decades. The coding system has no more room for new diseases and cannot take advantage of current medical innovations, especially in public health. For example, there is no method in the ICD-9 system to take note of biosurveillance — the national and worldwide tracking of viruses and epidemics — which has become of much greater importance in recent years.