For decades, measures of population health worldwide have been based on causes of death, diagnoses and prevalence of disease--indicators that, while meaningful, don't capture the full picture of the health status of countries. They can't, for example, impart how a health condition is affecting a patient's daily functioning following a heart attack or after undergoing hip replacement surgery. Nor can these measures adequately inform health policy-makers about the health-care service needs of the population.

For the past six years, APA's Practice Directorate has been collaborating with the World Health Organization (WHO) to revise the International Classification of Functioning, Disability and Health (ICF)--a system that will provide a more complete picture of the world's health status. This tool describes the impact of health conditions on people's levels of functioning in domains such as communicating, taking care of one's self, working and going to school. In addition to APA, other health professionals, people with disabilities, researchers, government officials and statisticians helped shape the development of the ICF.

APA believes such a system is important not only to improve individual treatment, but also to influence health policy. The ICF will serve broad social and health policy goals by expanding the concept of health beyond the disease model, says Geoff Reed, PhD, assistant executive director for professional development in APA's Practice Directorate. Use of the ICF, with its focus on human functioning, at population and individual levels, will better predict health service needs.

The ICF is positioned to be the universal system by which the functional aspects of health conditions are described. WHO's 191 member states are urged to use the ICF when reporting the health status of their countries, and ICF is already being used in several WHO surveys.

"It's really a whole new way of looking at health," says Marjorie Greenberg of the U.S. Department of Health and Human Services (HHS), secretary for the National Committee on Vital Health Statistics and head of the North American Collaborating Center for the ICD and ICF. "Over time the ICF will have quite an impact. It could be used in reimbursement methodologies and outcomes assessments," she says. The ICF can be a "common language for health professionals" to describe functional status and report assessment findings.

To enable health professionals to easily implement the ICF, APA has formed an interdisciplinary drafting team to develop a Procedural Manual and Guide for a Standardized Application of the ICF. Team members include psychologists David Peterson, PhD, Cille Kennedy, PhD, and John Jacobson, PhD, and speech-language pathologist Travis Threats, PhD, occupational therapist Susan Stark, PhD, and physical therapist Judy Hawley, PT.

The manual will help clinicians use the ICF system during evaluation and treatment encounters with patients and clients. "Without grassroots education that enables clinicians to implement the system, the World Health Organization's goal of fully capturing information on the health status of populations will be limited," says Jayne Lux, director of board operations in APA's Practice Directorate.

Without such an explanation of the system, "people get very nervous," says Kennedy, also of HHS and a member of the ICF drafting team. They need examples of how to interpret the codes for actual clinical experiences, she says. The manual will make the system easier to understand and will specify a standard approach to classifying functioning using the ICF.

So far, the team has held its first meeting to formulate a plan for the manual and is now drafting specific chapters. The initial draft will be written by experts in each area of human functioning and then reviewed and further developed by experts from other disciplines.

"By the time the chapters are written, they will have been reviewed and revised by many disciplines," says Lux.

Threats, who is among those working with APA on the manual, says the interdisciplinary approach to the manual fits the cross-disciplinary utility of the ICF. "ICF aims to help health professionals from many disciplines, such as speech, physical therapy and psychology, describe their patients' levels of functioning. How well can they do the things most important to them, like going to church or reading to their kids?" he says.

Says Jacobson, who is also on the drafting team, "The ICF is a nomenclature that provides us with a framework to describe how a person functions on an everyday basis in consistent terms. It's a potential tool for all sorts of applications. And it moves us more closely to where mainstream psychology and clinical practice is going to be."

"Although the scope of work necessary to write the manual is significant and time-consuming, we are confident the finished product will facilitate the use of the ICF system, thereby bringing a patient's functional status, in addition to their medical diagnosis, into the health-care dialogue," says Reed. "The inclusion of this important information will make a critical contribution in shaping health policy reform worldwide."