The Concept of Chronic Edema-A Neglected Public Health Issue and an International Response: The LIMPRINT Study.

Lymphedema has always been a neglected global health care problem. A central requirement for the development of any chronic disease is the clear use of public health definitions that can be used internationally to define populations. The term "lymphedema" has historically been defined as either primary, resulting from failure of lymphatic development, or secondary, following damage to the lymphatics (e.g., cancer treatment, injury, or filariasis). Attempts to integrate causes of edema arising from damage to the venous system or the effects of gravity, immobility, and systemic disease have rarely been integrated. More recently, the prominent role of the lymphatics in tissue fluid homeostasis in all forms of chronic edema has been recognized. These advances led to the development of the term: "Chronic edema: a broad term used to describe edema, which has been present for more than three months." It can be considered an umbrella term that includes not only conventional "lymphedema" but also chronic swelling, which may have a more complex cause. This definition has been adapted in the international epidemiology study (LIMPRINT) that identified people throughout the health and social care systems in participating countries. Clearer definitions will allow for examination of this important public health problem that is likely to escalate given the projections of an aging population with multiple comorbidities. It will be possible to define both the hidden mortality and morbidity associated with complications, such as cellulitis and the impact on health-related quality of life. This evidence is urgently required to lobby for increased resource and effective health care in an increasingly competitive health care arena in which more established conditions have greater priority and funding.

The Development and Validation of the LIMPRINT Methodology.

The acronym Limprint stands for Lymphedema IMpact and PRevalence INTernational and was run under the auspices of the International Lymphedema Framework (ILF), a charity dedicated to improving provision of care globally. The primary aim was to identify the number of people with chronic edema (chronic edema present for >3 months and due to a range of underlying etiologies and associated risk factors) within diverse health services in nine participating countries and to determine its impact using validated methods. An international protocol and sampling framework, online data capture system, and standard operating procedures were adopted. An international consensus was used to create a core data tool that covered 13 domains. Specialist data on demographics and disability, details of swelling, wounds, cancer, and health-related quality of life were also available for sites. The study protocol was designed to allow flexibility in the types of studies undertaken within complex health care systems. All cases were confirmed using the modified pitting test. Sensitivity and specificity for this method were determined in Japanese and European populations. Following confirmation of a chronic edema case, Lymphologists defined whether it was a primary of a secondary form. The study was designed to provide robust evidence that chronic edema is an important and unrecognized public health problem in health services with significant morbidity. Without evidence of the size and complexity, it will remain considered a rare phenomenon and people affected will be denied access to appropriate treatment that would allow them to have fulfilled and productive lives.