From analyses of individual patient data ( seven studies , 918 patients ) , we found baseline pain strongly associated with absolute , but not relative , MCID as patients with higher baseline pain needed larger pain reduction to perceive relief .
Conclusions The MCID in acute pain varied greatly between studies and was influenced by baseline pain , definitions of improved patients and study design .
Background The minimum clinical ly important difference ( MCID ) is used to interpret the clinical relevance of results reported by trials and meta-analyses as well as to plan sample sizes in new studies .
However , there is a lack of consensus about the size of MCID in acute pain , which is a core symptom affecting patients across many clinical conditions .
Prospective validation of clinically important changes in pain severity measured on a visual analog scale.
BACKGROUND In a l and mark hypothesis-generating study , Todd et al found that a difference of approximately 13 mm ( 95 % confidence interval [ CI ] 10 to 17 mm ) on a visual analog scale ( VAS ) represented the minimum change in acute pain that was clinical ly significant in a cohort of trauma patients . STUDY OBJECTIVE We test the hypothesis that the minimum clinical ly significant change in pain as measured by the VAS in an independent , more heterogeneous validation cohort is approximately 13 mm . METHODS This was a prospect i ve , observational cohort study of adults presenting to 2 urban emergency departments with pain . At 30-minute intervals during a 2-hour period , patients marked a VAS and were asked if their pain was " much less , " " a little less , " " about the same , " " a little more , " or " much more . " All data were obtained without reference to prior VAS scores . The minimum clinical ly significant change in pain was defined a priori as the difference in millimeters between the current and immediately preceding VAS scores when " a little more " or " a little less pain " was reported . RESULTS Ninety-six patients enrolled in the study , providing 332 paired pain measurements . There were 141 paired measurements design ated by patients as " a little less " or " a little more " pain . The mean clinical ly significant difference between consecutive ratings of pain in the combined " little less " or " little more " groups was 13 mm ( 95 % CI 10 to 16 mm ) . The difference between this finding and that of Todd et al was 0 mm ( 95 % CI -4 to 4 mm ) . CONCLUSION These data are virtually identical to previous findings indicating that a difference of 13 mm on a VAS represents , on average , the minimum change in acute pain that is clinical ly significant
From analyses of individual patient data ( seven studies , 918 patients ) , we found baseline pain strongly associated with absolute , but not relative , MCID as patients with higher baseline pain needed larger pain reduction to perceive relief .
Conclusions The MCID in acute pain varied greatly between studies and was influenced by baseline pain , definitions of improved patients and study design .
Background The minimum clinical ly important difference ( MCID ) is used to interpret the clinical relevance of results reported by trials and meta-analyses as well as to plan sample sizes in new studies .
However , there is a lack of consensus about the size of MCID in acute pain , which is a core symptom affecting patients across many clinical conditions .