Are Postoperative Patient Patient Reported Outcome Measures Influenced by Recall of Preoperative Scores? - a Randomized Controlled Trial
Phase: NA
Conditions: Degenerative Diseases, Spinal Cord
Sponsor: Centro Hospitalar De São João, E.P.E.

Cover letter 
 
Title of the study 
Are the results of patient reported outcome measures after spine surgery 
influenced by recall of preoperative scores? – a randomized controlled trial 
 
ID 
CHSJ1989 
 
 
Date of the document 
 
 February 1, 2021 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Study protocol 
 
Title of the study 
Are the results of patient reported outcome measures after spine surgery 
influenced by recall of preoperative scores? – a randomized controlled trial 
 
Objective 
To analyse the impact of recall bias of preoperative status on postoperative PROMs of 
patients submitted to surgery due to degenerative spine disease. 
 
Methods  
All adult patients with valid preoperative PROMs scores submitted to spine surgery 
due to degenerative pathology from 01.2019 to 04.2020 at our center were included in the 
studyand received questionnaires with a letter of consent. 
To evaluate the impact of recall bias on the scores of postoperative PROMs the patients of the 
intervention/recall group received postoperative questionnaires that included the preoperative 
answers for every individual question, whilst the control/no-recall group answered 
postoperative questionnaires without the preoperative responses. 
In preoperative and postoperative evaluation, to assess surgical outcome and disability, 
lumbar spine patients filled the back Core Outcome Measures Index (COMI) and Oswestry 
Disability Index (ODI) questionnaires, while patients with cervical degenerative spine disease 
completed the neck surgical COMI and the Neck Disability Index (NDI) 
All adult patients with valid preoperative PROMs scores submitted to spine surgery due to 
degenerative pathology from January 2019 to April 2020 at our center (spine unit of a 
neurosurgical department in a Portuguese university hospital) were included in the study and 
received PROMs questionnaires with a letter of consent. 
The primary outcome of the study was the postoperative COMI score, while the secondary 
outcomes were the postoperative NDI or ODI and EQ-5D scores. 
Effect size was obtained according to the quotient of minimal detectable change (MDC) for 
COMI and the standard deviation (SD) of the minimal clinical important difference (MCID).