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 .
Naproxen With Cyclobenzaprine, Oxycodone/Acetaminophen, or Placebo for Treating Acute Low Back Pain: A Randomized Clinical Trial.
IMPORTANCE Low back pain ( LBP ) is responsible for more than 2.5 million visits to US emergency departments ( EDs ) annually . These patients are usually treated with nonsteroidal anti-inflammatory drugs , acetaminophen , opioids , or skeletal muscle relaxants , often in combination . OBJECTIVE To compare functional outcomes and pain at 1 week and 3 months after an ED visit for acute LBP among patients r and omized to a 10-day course of ( 1 ) naproxen + placebo ; ( 2 ) naproxen + cyclobenzaprine ; or ( 3 ) naproxen + oxycodone/acetaminophen . DESIGN , SETTING , AND PARTICIPANTS This r and omized , double-blind , 3-group study was conducted at one urban ED in the Bronx , New York City . Patients who presented with nontraumatic , nonradicular LBP of 2 weeks ' duration or less were eligible for enrollment upon ED discharge if they had a score greater than 5 on the Rol and -Morris Disability Question naire ( RMDQ ) .  The RMDQ is a 24-item question naire commonly used to measure LBP and related functional impairment on which 0 indicates no functional impairment and 24 indicates maximum impairment . Beginning in April 2012 , a total of 2588 patients were approached for enrollment . Of the 323 deemed eligible for participation , 107 were r and omized to receive placebo and 108 each to cyclobenzaprine and to oxycodone/acetaminophen . Follow-up was completed in December 2014 . INTERVENTIONS All participants were given 20 tablets of naproxen , 500 mg , to be taken twice a day . They were r and omized to receive either 60 tablets of placebo ; cyclobenzaprine , 5 mg ; or oxycodone , 5 mg/acetaminophen , 325 mg . Participants were instructed to take 1 or 2 of these tablets every 8 hours , as needed for LBP . They also received a st and ardized 10-minute LBP educational session prior to discharge . MAIN OUTCOMES AND MEASURES The primary outcome was improvement in RMDQ between ED discharge and 1 week later . RESULTS Demographic characteristics were comparable among the 3 groups . At baseline , median RMDQ score in the placebo group was 20 ( interquartile range [IQR],17 - 21 ) , in the cyclobenzaprine group 19 ( IQR,17 - 21 ) , and in the oxycodone/acetaminophen group 20 ( IQR,17 - 22 ) . At 1-week follow-up , the mean RMDQ improvement was 9.8 in the placebo group , 10.1 in the cyclobenzaprine group , and 11.1 in the oxycodone/acetaminophen group . Between-group difference in mean RMDQ improvement for cyclobenzaprine vs placebo was 0.3 ( 98.3 % CI , -2.6 to 3.2 ; P = .77 ) , for oxycodone/acetaminophen vs placebo , 1.3 ( 98.3 % CI , -1.5 to 4.1 ; P = .28 ) , and for oxycodone/acetaminophen vs cyclobenzaprine , 0.9 ( 98.3 % CI , -2.1 to 3.9 ; P = .45 ) . CONCLUSIONS AND RELEVANCE Among patients with acute , nontraumatic , nonradicular LBP presenting to the ED , adding cyclobenzaprine or oxycodone/acetaminophen to naproxen alone did not improve functional outcomes or pain at 1-week follow-up . These findings do not support use of these additional medications in this setting . TRIAL REGISTRATION clinical trials.gov Identifier : NCT01587274
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 .