• Theory;
  • pressure ulcers;
  • moisture lesions;
  • friction ulcers;
  • literature review;
  • combined lesions



To review the risk factors included in pressure ulcer risk assessment scales and construct a theoretical model for identifying the etiological factors of skin ulcers, excluding those of systemic origin (e.g., venous, arterial, and neuropathic).


Consensus study with expert panel (Delphi Method) based on a structured review of the literature. A search was conducted of the main databases between 1962 and 2009 with no language limitations. All descriptive or validation studies were included, but the grey literature was excluded. After identifying the risk factors in each scale, they were grouped into risk dimensions as a basis for constructing a new theoretical model.


Eighty-three risk factors were identified in the 56 scales reviewed, and the risk factors were then classified by the expert panel into 23 risk dimensions. These dimensions were used to construct a new theoretical model (middle-range theory) for chronic wound development that explains the production mechanism of seven types of lesion: moisture, pressure, friction, combined pressure-moisture, combined pressure-friction, multifactorial lesions, and coadjuvant factors. These lesions were generically defined as dependence-related injuries.


Based on the classification of risk factors from the different scales into risk dimensions, a new middle-range theory was constructed that explains the production mechanism of seven dependence-related lesions considered to date as pressure ulcers.

Clinical Relevance

The prevention and treatment of these lesions requires a correct diagnosis and differentiation of their cause and management of the risk dimensions involved. The type of lesion also influences the selection of local approach.