To guide planning and to appraise available plans, we adapted the Haddon Matrix, a planning tool developed in the field of injury research and intervention [13] , and more recently applied to the public health response to bioterrorism, SARS [14] , and pandemic influenza [15] . The matrix consists of a grid of columns of four factors (human, agent, and physical and organisational environment) impacting upon the event [15] . Pandemic influenza may be perceived as a form of injury on a mass scale and the matrix helps us understand the multi-dimensional nature of epidemics and of the associated challenges that could be expected by general practice. The framework can be readily shared with public health units and other parts of the health system, as it identifies the general practice contributions to primary health care services and to public health surveillance and control. Because all disasters are local, the matrix is flexible enough to allow a focused analysis of the smallest unit of study, such as an individual, or group of general practitioners.