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 .
Efficacy of paracetamol for acute low-back pain: a double-blind, randomised controlled trial
BACKGROUND Regular paracetamol is the recommended first-line analgesic for acute low-back pain ; however , no high- quality evidence supports this recommendation . We aim ed to assess the efficacy of paracetamol taken regularly or as-needed to improve time to recovery from pain , compared with placebo , in patients with low-back pain . METHODS We did a multicentre , double-dummy , r and omised , placebo controlled trial across 235 primary care centres in Sydney , Australia , from Nov 11 , 2009 , to March 5 , 2013 . We r and omly allocated patients with acute low-back pain in a 1:1:1 ratio to receive up to 4 weeks of regular doses of paracetamol ( three times per day ; equivalent to 3990 mg paracetamol per day ) , as-needed doses of paracetamol ( taken when needed for pain relief ; maximum 4000 mg paracetamol per day ) , or placebo . R and omisation was done according to a central ised r and omisation schedule prepared by a research er who was not involved in patient recruitment or data collection . Patients and staff at all sites were masked to treatment allocation . All participants received best- evidence advice and were followed up for 3 months . The primary outcome was time until recovery from low-back pain , with recovery defined as a pain score of 0 or 1 ( on a 0 - 10 pain scale ) sustained for 7 consecutive days . All data were analysed by intention to treat . This study is registered with the Australian and New Zeal and Clinical Trial Registry , number ACTN 12609000966291 . FINDINGS 550 participants were assigned to the regular group ( 550 analysed ) , 549 were assigned to the as-needed group ( 546 analysed ) , and 553 were assigned to the placebo group ( 547 analysed ) . Median time to recovery was 17 days ( 95 % CI 14 - 19 ) in the regular group , 17 days ( 15 - 20 ) in the as-needed group , and 16 days ( 14 - 20 ) in the placebo group ( regular vs placebo hazard ratio 0·99 , 95 % CI 0·87 - 1·14 ; as-needed vs placebo 1·05 , 0·92 - 1·19 ; regular vs as-needed 1·05 , 0·92 - 1·20 ) . We recorded no difference between treatment groups for time to recovery ( adjusted p=0·79 ) . Adherence to regular tablets ( median tablets consumed per participant per day of maximum 6 ; 4·0 [ IQR 1·6 - 5·7 ] in the regular group , 3·9 [ 1·5 - 5·6 ] in the as-needed group , and 4·0 [ 1·5 - 5·7 ] in the placebo group ) , and number of participants reporting adverse events ( 99 [ 18·5 % ] in the regular group , 99 [ 18·7 % ] in the as-needed group , and 98 [ 18·5 % ] in the placebo group ) were similar between groups . INTERPRETATION Our findings suggest that regular or as-needed dosing with paracetamol does not affect recovery time compared with placebo in low-back pain , and question the universal endorsement of paracetamol in this patient group . FUNDING National Health and Medical Research Council of Australia and GlaxoSmithKline Australia
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 .