Hair apposition technique for scalp laceration repair: a randomized controlled trial comparing physicians and nurses (HAT 2 study)

Original Contribution

Hair apposition technique for scalp laceration repair: a randomized controlled trial comparing

physicians and nurses (HAT 2 study)B

Marcus Eng Hock Ong MBBS, MPHa,?, Yiong Huak Chan PhDb, Josephine Teo BSc, MSca, Saroja S ENa, Susan Yap RNa,

Pauline Hwee Yen Ang BSca, Swee Han Lim MBBSa

aDepartment of Emergency Medicine, Singapore General Hospital, Singapore 169608, Singapore

bBiostatistics Unit, Yong Loo Lin school of Medicine, National University of Singapore, Singapore 117597, Singapore

Received 27 April 2007; revised 13 July 2007; accepted 18 July 2007


Objectives: The hair apposition technique (HAT) is a new method of closing scalp lacerations in which hairs on either side of the wound are twisted together and secured with a tissue adhesive. We aimed to compare the effectiveness, complications, and benefits of HAT performed by nurses or doctors in a randomized, prospective trial.

Methods: We conducted the study in the ED from November 2002 to February 2005. Subjects were randomized to receive HAT either by doctors or nurses. All wounds were evaluated 7 days later. The outcomes Wound infection, wound healing, bleeding, and overall complications were measured, setting +-5% in the differences of the outcomes between the doctors and nurses as equivalence.

Results: There were 88 and 76 patients in the doctor and nurse groups, respectively. There were no significant differences in all Short-term outcomes between the doctors and nurses except for length of the procedure. The doctors had a shorter mean duration of procedure than the nurses (9.0 +- 5.6 vs 12.8 +- 7.5 minutes, P = .001).

Conclusion: The HAT can be safely performed by Trained nurses with equivalent outcomes as doctors.

(C) 2008


This paper was presented at (1) Singapore General Hospital 15th Annual Scientific Meeting, 21-22 April 2006; (2) Society for Emergency Medicine in Singapore 8th Annual Scientific Meeting, 19-20 January 2007; (3) 4th Asian Conference on Emergency Medicine in Kuala Lumpur, Malaysia, 23- 25 March 2007.

? Source of support: We acknowledge the support of the Department of

Clinical Research, Singapore General Hospital (SGH) (DCR/P15/2003) in providing the research grant.

* Corresponding author. Tel.: +65 63213590; fax: +65 63214873.

E-mail address: [email protected] (M.E.H. Ong).

The hair apposition technique (HAT) is a relatively new technique for closing certain scalp lacerations in which hairs on either side of the wound are twisted together and secured with a tissue adhesive. It has been shown to be equally acceptable as compared to the standard toilet and suture. In the United States, more than 12 million traumatic wounds are treated in EDs every year, many of these being traumatic lacerations of the scalp [1]. The HAT combines using a person’s own hair to close a wound with the use of tissue

0735-6757/$ – see front matter (C) 2008 doi:10.1016/j.ajem.2007.07.008

adhesives, whose use in wound care has been well documented [2-8].

We previously described a prospective, randomized, multi-center clinical trial comparing the HAT with standard suturing [9]. Advantages included fewer complications, a shorter procedure time, less pain, no need for shaving or removal of stitches, satisfactory wound healing, and high patient acceptance [9-12]. The HAT has also been shown to be more cost-effective than suturing [13].

In previous reports, HAT has been usually performed by physicians only. However, it is such a simple technique that it could possibly be performed by nonphysicians as well. A previous study suggested that this may be more cost- effective in the ED [13].

In this study, we aimed to compare the effectiveness, complications, and benefits of HAT performed by nurses compared with doctors in a randomized, prospective trial.



A randomized, prospective, controlled trial was used to compare the effectiveness, complications, and benefits of HAT performed by nurses compared with doctors. The study was approved by the hospital’s institutional review board. Patients gave written informed consent to participate in the study.


Prospective patients presenting with scalp lacerations to the ED of a tertiary level hospital were enrolled in this trial. The study began in November 2002 and ended in February 2005.


Patients of all ages were included in the trial. A scalp laceration was defined as a break of the skin on the hair- bearing area of the scalp resulting usually from blunt trauma. Other inclusion criteria included linear, nonstellate lacera- tions of the scalp, wound length less than 10 cm, and presence of scalp hair at least 3 cm in length. Exclusion criteria were severely contaminated wounds; actively bleeding (arterial) wounds not stopping after pressure is applied for at least 5 minutes, and unstable patients with unstable vital signs or neurological status requiring priority resuscitation.

Eligible patients had a patient information sheet explained to them and informed written consent was obtained. Patients were randomly assigned into either HAT performed by doctors or nurses using sealed envelopes generated from a table of random numbers. The allocation sequence was concealed in sequentially numbered, sealed opaque envelopes by a team

not involved in trial interventions. Consent and randomization occurred before any wound preparation or closure.


A minimal training period consisting of a 30-minute lecture and demonstration of the HAT technique was given to doctors and nurses involved in managing patients for the trial. Demonstration was by means of a training video with a recording of a procedure on an animal model. Subsequent training was on a skin pad model supervised by the study personnel.

Patients were recruited by the attending physicians on duty according to eligibility criteria. Wound preparation was according to the physician or nurse’s standard practice. For all patients, the wound was cleaned according to standard procedure. No local anesthetic was given. The wound was then closed by bringing together the hair on both sides of the wound. A single twist was then made. No actual knot was made. This was then secured with tissue glue (Fig. 1). After the procedure, the patient was instructed not to wash the wound for 2 days. No removal of stitches was required. The patient was encouraged to wash his hair after the third day and the glue was allowed to gradually fall off. An appointment was given to return for a wound inspection 1 week later. The adhesive used in this study was Histoacryl (B Braun Melsungen AG, Germany).


All procedure times were self-recorded by the individual operators to the nearest minute, by entering the start and ending time using a digital clock. The duration of procedure included wound preparation and procedure time. Pain perception was scored using a 10-point visual analog scale. Patients were asked to rate pain on a scale of 1 to 10, with 0 being no pain and 10 the most severe, unbearable pain. All scores were to the nearest integer. An equivalent pictorial scale was used for pediatric patients to score pain (Fig. 2). Patients were asked to score pain immediately after the procedure.

All patients enrolled in the trial were reviewed, in-person, at 7 days postprocedure. This review was by a senior physician not directly involved in the trial and not involved in the initial treatment of the patient. Reviewers were masked as to which treatment group the patient was in. During wound review, presence of any infection, bleeding, wound breakdown, and allergy was noted. Infection, bleeding, allergy, scab formation, and wound breakdown were scored as “present” or “absent.” Infection was considered present if there was pus, discharge from wound or erythema, edema, pain, and temperature suggesting cellulitis. The complication of bleeding was considered present if there was persistent/ recurrent bleeding after the procedure not stopping after at least 5 minutes of pressure. Allergy was defined as the presence of rashes, angioedema, or anaphylaxis. Scab

formation was defined as the presence of excessive crusting over the wound. Wound breakdown was considered to have occurred if any dehiscence, epidermal separation, or loss of edge apposition was present.

The reviewer was also asked if satisfactory wound healing had occurred. This was scored as “yes” or “no.” Wound healing was considered satisfactory if the treatment applied had resulted in recovery of epithelial integrity and no further treatment was required. For example, wound breakdown with dehiscence of skin margins would be considered unsatisfactory wound healing and would require further treatment (eg, resuture). However, wounds with recovery of epithelial integrity but with excessive scar tissue would usually not require any further intervention and were considered to have healed satisfactorily. Such patients would only be followed up weekly for inspections until the scar was mature.

If any wound complications were present or healing was not complete, the patient was asked to return for weekly assessments and treatment until complications resolved and healing was complete.

Data analysis

Sample size was calculated on the postulation that the patients either seen by doctors or nurses have a 98% healing rate. With a declared equivalence region of 5% for the difference in wound healing rate, 130 patients to be randomized to each group will have a power of 80% to achieve equivalence. Other outcomes of interest were wound infection, bleeding, wound breakdown, and overall complications.

Data were entered into Access 97 (Microsoft, Inc, Redmond, Wash) and analyzed using SPSS version 14.0 (SPSS, Inc, Chicago, Ill). The analysis was on an intention- to-treat basis. Ninety-five percent confidence interval (CI) for the differences in the above primary outcomes between the doctor and nurse groups was calculated and equivalence declared when the CI did not cross the +-5% threshold. Pearson’s ?2 test or Fisher exact test was used to assess differences between the 2 groups in qualitative data (sex, race, wound contamination, etc). Differences in quantitative variables (age, length of wound, etc) were determined using independent-samples t test if normality and homogeneity assumptions were satisfied; otherwise, the nonparametric equivalent Mann-Whitney U test was applied. Statistical significance was set at P b .05.


Fig. 3 shows the profile of the trial. There were 88 and 76 patients in the doctor and nurse groups, respectively. Fourteen patients were lost to follow-up in the doctor group and 16 in the nurse group. There was no significant

Fig. 1 Hair apposition technique. (1) Choose 4 to 5 strands of hair in a bundle on either side of the scalp laceration. (2) Using artery forceps, cross the strands. (3) Make a single twist to appose wound. (4) Secure with a single drop of glue.

Fig. 2 Pain scale for children.

difference in age, sex, race, or wound characteristics between groups (Table 1).

The primary outcomes of wound infection, wound healing, and overall complications were comparable for both the doctors and nurses as these 95% CI for the differences did not cross the +-5% threshold (Table 2).

For the secondary outcomes, the doctors (9.0 +- 5.6 minutes) compared to the nurses (12.8 +- 7.5 minutes) had a significantly lower mean duration of procedure (P = .001) (Table 3). However, there was no significant difference in pain scores during treatment for either group (P = .83).


In this study, we found that nurses were able to perform HAT with equivalent complication rates compared to doctors. Although doctors were faster in performing the procedure (mean difference of 3.8 minutes), this may not be a true reflection of the actual time spent. We found that when recording the doctor’s procedure time, physicians may not have included the time spent by a nurse preparing the patient, as well as dressing the wound and clearing instruments

Fig. 3 Profile of the randomized controlled trial.

afterward. However, this may have been included in the nurses’ recording of procedure time.

Although the doctor-patient ratios vary in various countries [14], many EDs and Outpatient services have experienced a physician shortage [15] and turned increas- ingly to nonphysicians to perform part of their traditional roles [15-24]. Studies have proposed that nurse practitioners or registered nurses can perform some of these physician duties as effectively and in a more cost-efficient manner [16-22]. Some studies also propose that registered nurses can give more patient-focused and sympathetic care [20,25-28]. Emergency departments have also implemented protocols allowing registered nurses to order x-rays [23].

Table 1 Characteristics of patients in the doctor and nurse groups


Doctor group, n (%)

(n = 88)

Nurse group, n (%)

(n = 76)




Mean (SD)

38.1 (20.8)

42.9 (20.8)


Median (range)

33.9 (89.4)

41.2 (89.2)



58 (65.9)

47 (61.8)



30 (34.1)

29 (38.2)



63 (71.6)

55 (72.4)



6 (6.8)

6 (7.9)


7 (8.0)

12 (15.8)


12 (13.6)

3 (3.9)

Multiple wounds


5 (5.7)

8 (10.5)



83 (94.3)

68 (89.5)



87 (98.9)

73 (96.1)



1 (1.1)

3 (3.9)

Length of wound, cm

Mean (SD)

2.6 (1.5)

2.8 (1.5)


Median (range)

2.0 (5.5)

3.0 (7.5)



68 (77.3)

63 (82.9)



19 (21.6)

13 (17.1)


1 (1.1)

0 (0)

Time to treatment, h

Mean (SD)

3.5 (5.2)

3.7 (3.8)


Median (interquartile

2.3 (47.0)

3.0 (20.5)




0 (0)

0 (0)


88 (100.0)

76 (100.0)

Diabetes mellitus


3 (3.4)

4 (5.3)



85 (96.6)

72 (94.7)



1 (1.1)

0 (0)



87 (98.9)

76 (100.0)


Doctor group, n (%) (n = 88)

Nurse group, n (%) (n = 76)


95% CI








(-3.9 to 4.4)


















Wound breakdown







(-4.0 to 1.3)






Scab formation







(-17.1 to 9.9)






Any complication

(infection, scab formation, bleeding,

or wound breakdown)







(-17.2 to 10.7)






Wound healed







(-4.6 to 3.9)






Finally, we found that HAT may be a suitable procedure for nurses to perform in the ED. This might be more cost- effective [13] and can free physicians to attend to other, more complicated cases. The overall complication rate for HAT was even slightly lower in the nurse group, although this was not statistically significant.

Table 2 Complications reported in patients of the doctor and nurse groups


Limitations of the study include that recording of procedure time was by the operator, which might be subjective as we have described above. Also, definitions for the start and end timings may not have been closely adhered to. This might have led to unfair comparisons between groups. Although more labor-intensive, future studies could

Table 3 Secondary outcome of patients in the doctor and nurse groups

be performed with objective recording of procedure times by independent third parties, where possible.

Also the short review period of 1 week is also a limitation. However, the study is limited to short outcomes and therefore does not address scar formation or long-term appearance. The outcome “scab formation” is an attempt to describe the presence of excessive wound crusting at 1 week, but this probably does not correlate with later scar appearance.

Also, wound preparation was not completely standardized and varied slightly with the practitioner. The primary investigators were unable to be present all the time to ensure conformity of technique. However, we feel the very merit of HAT is that it is a simple technique that can be mastered quickly by anyone.

Limitations of the HAT method include the fact that patients without hair or with very short strands would not be

Doctor group, n (%) (n = 88)

Nurse group, n (%) (n = 76)

Mean difference (95% CI)

P value

Duration of procedure, min

Mean (SD)



12.8 (7.5)

3.8 (1.7 to 5.8)


Median (range)



10.0 (28.0)

Pain score during treatment

Mean (SD)



2.8 (2.3)

-0.1 (-0.9 to 0.7)


Median (range)



2.0 (9.0)

Pain score during follow-up

Mean (SD)



0.7 (1.1)

-0.1 (-0.6 to 0.4)


Median (range)



0 (4.0)

suitable candidates for HAT. Profusely bleeding scalp wounds, especially those due to arterial bleeding, would probably do better with sutures, which allow under-running of the wound. Grossly contaminated wounds may also require trimming or shaving of the hair to allow proper cleansing and debridement.


Although doctors were faster in performing the procedure (mean difference of 3.8 minutes), nurses were able to perform HAT with similar complication rates compared to doctors. The HAT is a simple technique to master and can be safely performed by trained nurses.


We would like to thank the nurses, staff, and doctors of the Department of Emergency Medicine, SGH for their help and support. Special thanks to Mr David Yong and Ms Yan Xiu Yuan.


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