Non-steroidal or opioid analgesia use for children with musculoskeletal injuries (the No OUCH study): statistical analysis plan
Authors: Heath Anna , Yaskina Maryna , Hopkin Gareth , Klassen Terry P. , McCabe Christopher , Offringa Martin , Pechlivanoglou Petros , Rios Juan David , Poonai Naveen , Ali Samina ,   on behalf of the KidsCAN PERC Innovative Pediatric Clinical Trials No OUCH Study Group, Cote Dennis , Meckler Garth , Roback Mark , Kharbanda Anupam , Cohen Eyal , Nigrovic Lise , ‘t Jong Geert W. , Ali Samina , Poonai Naveen , Rajagopal Manasi , Richer Lawrence , Thull-Freedman Jennifer , McGrath Patrick , Graham Timothy A. D. , Hartling Lisa , Gouin Serge , Stang Antonia , Sawyer Scott , Bhatt Maala , Auclair Marie Christine , Kim Kelly , Bourrier Lise , Dawson Lauren , DaSilva Kamary Coriolano , McCabe Christopher , Hopkin Gareth , Round Jeff , Willan Andy , Yaskina Maryna , Heath Anna , Rios David , Offringa Martin , Pechlivanoglou Petros , Pullenayegum Eleanor , Marples Pamela , Watts Rick , Klassen Terry , Erickson Tannis , Foot Brendon , Hickes Serena , Schreiner Kurt , Leung Julie , Drendel Amy 
Published: September 2020

Abstract
Background
Pediatric musculoskeletal injuries cause moderate to severe pain, which should ideally be addressed upon arrival to the emergency department (ED). Despite extensive research in ED-based pediatric pain treatment, recent studies confirm that pain management in this setting remains suboptimal. The No OUCH study consist of two complementary, randomized, placebo-controlled trials that will run simultaneously for patients presenting to the ED with an acute limb injury and a self-reported pain score of at least 5/10, measured via a verbal numerical rating scale (vNRS). Caregiver/parent choice will determine whether patients are randomized to the two-arm or three-arm trial. In the two-arm trial, patients will be randomized to receive either ibuprofen alone or ibuprofen in combination with acetaminophen. In the three-arm trial, patients can also be randomized to a third arm where they would receive ibuprofen in combination with hydromorphone. This article details the statistical analysis plan for the No OUCH study and was submitted before the trial outcomes were available for analysis.

Methods/design
The primary endpoint of the No OUCH study is self-reported pain at 60 min, recorded using a vNRS. The principal safety outcome is the presence of any adverse event related to study drug administration. Secondary effectiveness endpoints include pain measurements using the Faces Pain Scale-Revised and the visual analog scale, time to effective analgesia, requirement of a rescue analgesic, missed fractures, and observed pain reduction using different definitions of successful analgesia. Secondary safety outcomes include sedation measured using the Ramsay Sedation Score and serious adverse events. Finally, the No OUCH study investigates the reasons given by the caregiver for selecting the two-arm (Non-Opioid) or three-arm (Opioid) trial, caregiver satisfaction, physician preferences for analgesics, and caregiver comfort with at-home pain management.

Discussion
The No OUCH study will inform the relative effectiveness of acetaminophen and hydromorphone, in combination with ibuprofen, and ibuprofen alone as analgesic agents for patients presenting to the ED with an acute musculoskeletal injury. The data from these trials will be analyzed in accordance with this statistical analysis plan. This will reduce the risk of producing data-driven results and bias in our reported outcomes.

Trial registration
ClinicalTrials.gov NCT03767933. Registered on December 7, 2018.