Such interventions would have the potential to reduce the prevalence of chronic pain in the population .
Although certain risk factors can identify individuals who are most likely to develop chronic pain , few interventions to prevent chronic pain have been identified .
To facilitate the identification of preventive interventions , an IMMPACT meeting was convened to discuss research design considerations for clinical trials investigating the prevention of chronic pain .
We present general design considerations for prevention trials in population s that are at relatively high risk for developing chronic pain .
Risk factors for postherpetic neuralgia in patients with herpes zoster
Objectives : To identify risk factors for postherpetic neuralgia ( PHN ) using a vali date d definition of this chronic neuropathic pain syndrome , to determine combinations of risk factors that identify patients with a high risk of developing PHN , and to examine the characteristics of patients with subacute herpetic neuralgia , that is , pain that persists beyond the acute phase of herpes zoster but that resolves before PHN can be diagnosed . Methods : The authors examined baseline and follow-up data from 965 herpes zoster patients enrolled within 72 hours of rash onset in two clinical trials of famciclovir .  Results : Univariate and multivariate analyses indicated that older age , female sex , presence of a prodrome , greater rash severity , and greater acute pain severity made independent contributions to identifying which patients developed PHN . Patients with subacute herpetic neuralgia who did not develop PHN were significantly younger and had less severe acute pain than PHN patients but were significantly more likely to have severe and widespread rash than patients without persisting pain . Conclusions : The independent contributions to the prediction of PHN made by older age , female sex , presence of a prodrome , greater rash severity , and greater acute pain severity suggest that these risk factors reflect different mechanisms that each contribute to the development of PHN . Subacute herpetic neuralgia that does not progress to PHN may reflect peripheral tissue damage and inflammation caused by a particularly severe or widespread rash
Such interventions would have the potential to reduce the prevalence of chronic pain in the population .
Although certain risk factors can identify individuals who are most likely to develop chronic pain , few interventions to prevent chronic pain have been identified .
To facilitate the identification of preventive interventions , an IMMPACT meeting was convened to discuss research design considerations for clinical trials investigating the prevention of chronic pain .
We present general design considerations for prevention trials in population s that are at relatively high risk for developing chronic pain .