Variability in Self-Reported Preoperative Pain Between Clinic Visits and Day of Surgery

Preoperative pain is routinely reported in the clinical literature and is benchmarked against numerous clinical parameters, necessitating that baseline preoperative pain is precisely defined and exhibits minimal variability. The goal of this study was to determine whether there is variability in pain scores obtained on the day of surgery (DOS) compared to preoperative clinic visits.  Methods: We conducted a retrospective analysis of total knee arthroplasty (TKA), total hip arthroplasty (THA), and spinal fusion (SF). Self-reported 0-10 numeric rating scale (NRS) pain scores were compared between clinic visits and DOS in 1,567 patients. The primary intent was to determine if there were differences between clinical and DOS NRS scores. Secondary analyses were performed by stratifying the results by procedure, gender, and time of clinic visit. Additionally, we performed a qualitative literature review to assess how the timing of preoperative pain assessments is reported.

Our primary analysis found patients undergoing painful procedures reported significantly greater pain in the clinic compared to DOS, with a median difference of 3 and an interquartile range (IQR) of 6 (p < 0.0001). For our secondary analyses, similar differences between clinic and DOS were found for TKA (3; IQR 7; p < 0.0001), THA (3; IQR 7; p < 0.0001), and SF (2; IQR 5; p < 0.0001). Stratification by gender revealed comparable reductions (p = 0.6985). Finally, these discrepancies were consistent across preoperative clinic visits ranging from 1-90 days prior to surgery compared to DOS (p = 0.1944). Our qualitative literature review revealed that the timing of preoperative pain acquisition is rarely reported.

Our results indicate that the degree of patient-reported pain differs drastically between clinic visits and DOS and identify a potential source of interstudy variability, highlighting the importance of defining the timing and setting of preoperative pain assessments.