The timing of hair removal has generally been
based on facilitating ease of preparatory activity
by health care workers or by facility policy rather
than scientific evidence. Although experts have
long held the view that hair removal close to the
time of surgery may reduce the risk of surgical
site infection, surveys have found a majority of
hospitals policy is to remove surgical site hair the
evening before surgery.
A randomised study of 1,013 patients
demonstrated no significant difference in surgical
site infection when shaving surgical site hair the
evening before surgery, or the day of surgery
(p=0.69). The same study compared use of
clippers on the evening before surgery, and the
day of surgery and found surgical incision sites
categorised as clean were statistically less likely
to develop infection when surgical hair removal
was performed the morning of surgery (p=0.027
on discharge). This effect was maintained at 30-
day follow up (p=0.006). One observational
study of 536 patients prospectively studied the
timing of preoperative shaving. This study found
patients shaved 12 or more hours prior to
surgery were at no greater risk of surgical site
infection compared with patients shaved less
than 2 hours prior to surgery (p=0.64). However,
subgroup analysis found wounds that had been
categorised as "clean" (see Table 2) were less
likely to result in a surgical site infection if hair
was removed with clippers less than 2 hours
prior to surgery (p0.01), a statistically
significant result. Observational studies have
tended to favour clipping or suggest no
difference, although, two better quality studies
demonstrated a significant benefit with the use of
clippers compared to shaving if preoperative hair
removal is required.