Comparing the effectiveness and lubricity of a novel Shea lubricant to 2% lidocaine gel for digital rectal examination: a randomized non-inferiority trial

Abstract

This study compared the level of lubricity and pain reduction of a novel shea lubricant to 2% lidocaine gel during digital rectal examination (DRE). Our research group performed a 9-week single-blind non-inferiority trial at the Ho Teaching Hospital involving 153 patients. The primary outcome measure was the mean pain difference during the procedure using a Visual Analogue Scale. 75 and 78 patients were randomized to the shea lubricant and 2% lidocaine gel groups respectively. The analysis considered the per-protocol population. The mean pain difference at endpoint was Δ − 0.01. The 95% lower confidence interval was a -0.595 difference in means, above the non-inferiority (NI) limit of − 0.720, thus establishing non-inferiority (Δ − 0.01, 95% CI − 0.59 to 0.57, NI − 0.72). With secondary outcome measures, perianal pruritus (p = 0.728), discomfort (p = 0.446), bowel urgency (p = 0.077) and urinary urgency (p = 0.841) were similar during the procedure. Shea lubricant had better lubricity and ease of use (p = 0.002). While the novel shea lubricant achieved similar level of pain reduction as obtained with 2% lidocaine gel, it had better ease of performance and lubricity.