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 .
Clinically significant differences in acute pain measured on self-report pain scales in children.
OBJECTIVES The objective was to determine the minimum and ideal clinical ly significant differences ( MCSD , ICSD ) in  pain intensity in children for the Faces Pain Scale-Revised ( FPS-R ) and the Color Analog Scale ( CAS ) and to identify any differences in these estimates based on patient characteristics . METHODS This was a prospect i ve study of children aged 4 to 17 years with acute pain presenting to two urban pediatric emergency departments . Participants self-reported their pain intensity using the FPS-R and CAS and qualitatively described their changes in pain . Changes in pain score reported using the FPS-R and CAS that were associated with " a little less " and " much less " pain ( MCSD and ICSD , respectively ) were identified using a receiver operating characteristic-based method and expressed as raw change score and percent reductions . Estimates of MCSD and ICSD were determined for each category of initial pain intensity ( mild , moderate , and severe ) and patient characteristics ( age , sex , and ethnicity ) . Post hoc exploratory analyses evaluated categories of race , primary language , and etiology of pain . RESULTS A total of 314 children with acute pain were enrolled ; mean ( ±SD ) age was 9.8 ( ±3.8 ) years . The FPS-R raw change score and percent reduction MCSD estimates were 2/10 and 25 % , with ICSD estimates of 3/10 and 60 % . For the CAS , raw change score and percent reduction MCSD estimates were 1/10 and 15 % , with ICSD estimates of 2.75/10 and 52 % . For both scales , raw change score and percent reduction estimates of the MCSD remained unchanged in children with either moderate or severe pain . For both scales , estimates of ICSD were not stable across categories of initial pain intensity . There was no difference in MCSD or ICSD based on age , sex , ethnicity , race , primary language , or etiology of pain . CONCLUSIONS The MCSD estimates can be expressed as raw change score and percent reductions for the FPS-R and CAS . These estimates appear stable for children with moderate to severe pain , irrespective of age , sex , and ethnicity . Estimates of ICSD were not stable across different categories of initial pain intensity , therefore limiting their potential generalizability
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 .