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 .
Validation of a verbally administered numerical rating scale of acute pain for use in the emergency department.
OBJECTIVES Verbally administered numerical rating scales ( NRSs ) from 0 to 10 are often used to measure pain , but they have not been vali date d in the emergency department ( ED ) setting . The authors wished to assess the comparability of the NRS and  visual analog scale ( VAS )  as measures of acute pain , and to identify the minimum clinical ly significant difference in pain that could be detected on the NRS . METHODS This was a prospect i ve cohort study of a convenience sample of adults presenting with acute pain to an urban ED . Patients  verbally rated pain intensity as an integer from 0 to 10 ( 0 = no pain , 10 = worst possible pain ) , and marked a 10-cm horizontal VAS bounded by these descriptors .  VAS and NRS data were obtained at presentation , 30 minutes later , and 60 minutes later . At 30 and 60 minutes , patients were asked whether their pain was " much less , " " a little less , " " about the same , " " a little more , " or " much more . " Differences between consecutive pairs of measurements on the VAS and NRS obtained at 30-minute intervals were calculated for each of the five categories of pain descriptor . The association between VAS and NRS scores was expressed as a correlation coefficient . The VAS scores were regressed on the NRS scores in order to assess the equivalence of the measures . The mean changes associated with descriptors " a little less " or " a little more " were combined to define the minimum clinical ly significant difference in pain measured on the VAS and NRS . RESULTS Of 108 patients entered , 103 provided data at 30 minutes and 86 at 60 minutes . NRS scores were strongly correlated to VAS scores at all time periods ( r = 0.94 , 95 % CI = 0.93 to 0.95 ) . The slope of the regression line was 1.01 ( 95 % CI = 0.97 to 1.06 ) and the y-intercept was -0.34 ( 95 % CI = -0.67 to -0.01 ) . The minimum clinical ly significant difference in pain was 1.3 ( 95 % CI = 1.0 to 1.5 ) on the NRS and 1.4 ( 95 % CI = 1.1 to 1.7 ) on the VAS . CONCLUSIONS The findings suggest that the verbally administered NRS can be substituted for the VAS in acute pain measurement
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 .