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An evaluation of the user acceptability of chlorhexidine handwash formulations
Journal
of Hospital
Infection
(1991)
An evaluation chlorhexidine D. Scott, The Pharmacy,
18 (Supplement
B), 51-55
of the user acceptability handwash formulations
A. Barnes,
Dudley Road Hospital Aston University,
M. Lister
of
and P. Arkell
and Pharmaceutical Birmingham, UK
Sciences
Institute,
Summary:
Four similar-looking preparations containing 4% chlorhexidine (‘Hibiscrub’, Surgiscrub’, ‘Uniscrub’, ‘Macrocide’) were compared in a single-blind, randomized study in a group of 73 volunteers. The volunteers washed their hands with each preparation ten times over 9 h, one preparation day-’ on each of four days over two weeks. The acceptability of the agents was assessed using visual analogue scales which were analysed by paired ttest. There were marked differences between the products. ‘Uniscrub’ smelled worse (PC 0.003) and felt worse than the others (PC 0,003). ‘Hibiscrub’ lathered well but ‘Macrocide’ was found easiest to rinse off. ‘Hibiscrub’ and ‘Surgiscrub’ were the least irritant and had the best visual appearance. Despite apparent similarities, these chlorhexidine formulations varied in acceptability to users.
Introduction
The hands of hospital personnel play an important role in the transmission of infection.lm3 Handwashing is one of the main methods for reducing cross-infection in hospital wards. Its effectiveness in reducing the spread of infection depends on several factors: the preparation used, the extent of contamination, the occasion of handwashing, the handwashing technique and the type and survival of the organisms present. The use of a product also depends on user acceptability, and any reluctance to wash hands could jeopardize the success of the aseptic procedure. ‘Hibiscrub’, ICI’s antiseptic handwash preparation containing chlorhexidine gluconate, has been used for many years in hospital wards, but there are now several similar products on the UK market, whose bacteriological efficacy has been tested and found to be adequate.4p5 This study was designed to compare the user acceptability of four antiseptic agents. All were pink, soapy solutions containing 4% chlorhexidine. Materials
and
methods
Seventy-three volunteers, who were not familiar with any of the products tested, were recruited into the study. Subjects with broken skin, eczema and known allergies to chlorhexidine or soap were excluded. 03954701/91/06B051
+OS $03.00/O
Q 1991 The Hospital
51
Infection
Socmy
D. Scott et al.
52
The four agents used were ‘Hibiscrub’ (ICI Pharmaceuticals), (Seaton Health Products) and ‘Macrocide’ (Macarthys), ‘Uniscrub’ ‘Surgiscrub’ (Ivex). Each agent was supplied in its original square 500 ml plastic bottle, which was entirely masked. The bottles were fitted with identical dispensers calibrated to deliver 4 ml per actuation. The code letters used to identify the preparations were changed each session to avoid volunteers biasing others by describing the products. Each volunteer used a different preparation on each of 4 days, within one following a standard protocol. The order in which 2-week period, preparations were used was randomized using a factorial design. The containers were weighed daily to determine the quantity of scrub used. Physicochemical properties of the agents were assessed (Table I). Handwashing procedure On each occasion, the hands were washed without scrubbing ten times over 9 h, allowing a minimum of 15 min between washes. Cold water was available for rinsing and paper towels for drying. The technique used was that which is taught to hospital staff. Acceptability assessments Volunteers were asked to assess the product they had used marking their responses on 100 mm visual analogue scales (VAS). These scales assess between the two extremes of bad (0 mm) to good (100mm). The factors assessed were: smell, appearance, feel, lather, ease of rinsing and itchiness. In addition, volunteers were asked if they would be prepared to use the preparation routinely, and to say which of the following adjectives could be applied to their hands: dry, soft, sore, normal, rough, sticky, clean. Laboratory lather tests for each product were performed to compare with volunteer assessments. A mixture of 5 ml of soap and 10 ml of tap water was shaken vigorously in a stoppered cylinder. The volume of lather produced was noted at 0, 5, 10, 15 and 30 min. Statistics VAS scores for each product were compared using the paired t-test. Probability values quoted are two-tailed with values less than 0,05 regarded as significant. Non-parametric tests, including the Wilcoxon signed rank test, confirmed the differences described by the t-test. Table
I. Physicochemical
Physicochemical Chlorhexidine Isopropanol PH Density Viscosity
property content
properties of the handwash in the study
formulations
Range of measured values 3.95-4.14%
C&6.4% 5.2-7.1 l.Ol-1.04gml-’
13.5-92.5 CS
used
User Table
acceptability II.
Index for measurement stickiness
of chlorhexidine
Assessment of the sensitivity
53
formulations of paired
VAS
scales
of ‘Betadine’
Soap
Weight of glass beads (mg) Mean VAS score (mm) Paired VAS score (p)
35
17
3
‘Hibisol’
‘Hibiscrub’
64 3 0.04
10
0.25
2460 43 0~0001
80
Smell
a
Feel Macrocide
Figure 1. Mean VAS scores Reproduced with permission.6
Look H
for
Uniscrub
perceived
Lather 0
properties
Surgiscrub of antiseptic
Rinsing m
Itchiness
Hibiscrub
handwashing
agents.
Sensitivity of paired VAS scales The sensitivity of paired VAS scales, as used in this study, was illustrated by a second study of similar design in 33 volunteers. The volunteers wore latex dental gloves for 2 h during which time they washed their gloved hands six times with either unmedicated soap, ‘Betadine’, ‘Hibiscrub’ or ‘Hibisol’. The stickiness of the gloves was measured by VAS scales, and by a standardized laboratory method which measured the weight of 180 pm Ballotini glass beads adhering to the gloves. Table II indicates the mean weight of beads taken up by each glove after using these preparations. Results
One volunteer withdrew from the study because of skin soreness. The mean quantities of the four scrubs used were not significantly different.
D. Scott et al.
54 Table
III.
Number
of positive responses to proposed adjectives describing following washing. Reproduced with permissionb Number ‘Macrocide’
Normal Clean Sore Rough Sticky
26 38 2 10 13
(36) (53) (3) (14) (18)
‘Uniscrub’ 18 40 4 14 13
(25) (56) (6) (19) (18)
the condition
of hands
(%) ‘Surgiscrub’ 32 (44) 45 (63) 3 (4) 3 (4) 11 (15)
‘Hibiscrub’ 26 (36) 40 (56) 0 (0) 6 (8) 8 (11)
The mean VAS scores are shown in Figure 1. ‘Uniscrub’ had the lowest mean VAS ratings for smell, and the difference from each of the other three products was highly significant (P< 0.003). There was a similar distinction with regard to feel, which was statistically significant to the same degree. ‘Macrocide’ and ‘Uniscrub’ both had lower scores for appearance than either ‘Hibiscrub’ or ‘Surgiscrub’ (P< 0.05). ‘Macrocide’ and ‘Uniscrub’ also showed a trend towards lower mean scores for itchiness, though this did ‘Macrocide’ and ‘Hibiscrub’ scored not reach statistical significance. highest for ease of rinsing, and ‘Hibiscrub’ had significantly higher lather ratings than the other products. ‘Uniscrub’ had the lowest rating for lather production. Laboratory measurements of the lather volume showed no differences between products. Two of the adjectives, soft and dry, were found not to be helpful descriptions of washed hands, because opinion as to their desirability varied. Results for the remaining five adjectives are shown in Table III. In reply to the question of whether volunteers would be prepared to use the product routinely, the most favourable response was obtained with ‘Surgiscrub’ (47%). Next came ‘Hibiscrub’ (4.5%), followed by ‘Macrocide’ (44%) and ‘Uniscrub’ (17%). Discussion
In order to reduce the incidence of cross-infection in hospitals, health care workers must wash their hands frequently and in the correct manner. Any reluctance to do so will render the antiseptic process ineffective. Clearly, the acceptability of antiseptic products to users is important and in practice, unpleasant or demanding protocols are not fully followed. This study detected differences in user acceptability between four antiseptic agents which all contained 4% chlorhexidine. Of the four agents tested, ‘Uniscrub’ was overall the least popular on the basis of VAS scores and direct questioning, while there was no clear distinction between ‘Macrocide’ and ‘Surgiscrub’. ‘Hibiscrub’ was the most popular preparation in terms of feel, appearance, rinsing, lathering and causing the least amount of soreness and roughness.
User acceptability
of chlorhexidine
formulations
55
The sensitivity of paired VAS scales was confirmed by the second study. The mean VAS scores merely identified the greatest difference between products, namely the stickiness of ‘Hibisol’ compared to soap. The VAS paired t-test, expressed as a probability of a difference from the use of soap, identified that difference and highlighted another, between ‘Hibiscrub’ and soap. Thus, paired VAS scales are a highly sensitive, and simple, method for comparing subjective properties that may or may not have an objective correlate. Laboratory tests on the physicochemical properties of the chlorhexidine scrubs (West Midlands Pharmacy Quality Control Laboratory) did not reveal any obvious causes of the variation in acceptability, despite measurable differences. All contained the stated quantity of chlorhexidine ( f 5 %) and were of similar density. The viscosities varied considerably, but the order of values did not match the order of acceptability for ‘feel’ or Two products (‘Hibiscrub’ and ‘Uniscrub’) contained ease af rinsing. isopropanol but the only property which appeared to be affected by that was smell. ‘Uniscrub’ had a very unpopular smell but Hibiscrub was not distinguishable from the non-propanol preparations. ‘Uniscrub’ also had the highest pH but it was not above the range which is typical of liquid soaps. It was interesting that a laboratory test for lathering capacity failed to predict the subjective responses of users accurately. It had been thought that poor lathering would result in an increased amount of soap used, but this was not the case. Potential users of antiseptic soaps should be consulted prior to the placement of large orders, as it is clear that decisions based purely on cost, antibacterial efficacy and technical information will not necessarily lead to adequate hand antisepsis.’ References 1. Maki
DG.
Control
of colonization
and transmission
of pathogenic
bacteria
in the hospital.
Ann Intern Med 1978; 89: 777-780. 2. Reybrouck G. Role of the hands in the spread of nosocomial infections. J Hosp Infect 1983; 4: 103-110. 3. Maki DG. The use of antiseptics for handwashing by medical personnel. J Chemother 1989 1: (Suppl): 3-11. 4. Ayliffe GAJ, Babb JR, Davies JG & Lilly HA. Hand disinfection: a comparison of various agents in laboratory and ward studies. J Hosp Infect 1988; 11: 226-243. 5. Lee MG, Hunt P, Felix D. A comparison of two bactericidal handwashing agents containing chlorhexidine. J Hasp Infect 1988; 12: 59-63. 6. Scott DK, Lister MR. An evaluation of the user-acceptability of four surgical scrubs.
PharmJ 7. Ayliffe
1990; 245: 120-121. GAJ.
Standardization
of disinfectant
testing.
J Hosp Infect 1989; 13: 211-216.
of Hospital
Infection
(1991)
An evaluation chlorhexidine D. Scott, The Pharmacy,
18 (Supplement
B), 51-55
of the user acceptability handwash formulations
A. Barnes,
Dudley Road Hospital Aston University,
M. Lister
of
and P. Arkell
and Pharmaceutical Birmingham, UK
Sciences
Institute,
Summary:
Four similar-looking preparations containing 4% chlorhexidine (‘Hibiscrub’, Surgiscrub’, ‘Uniscrub’, ‘Macrocide’) were compared in a single-blind, randomized study in a group of 73 volunteers. The volunteers washed their hands with each preparation ten times over 9 h, one preparation day-’ on each of four days over two weeks. The acceptability of the agents was assessed using visual analogue scales which were analysed by paired ttest. There were marked differences between the products. ‘Uniscrub’ smelled worse (PC 0.003) and felt worse than the others (PC 0,003). ‘Hibiscrub’ lathered well but ‘Macrocide’ was found easiest to rinse off. ‘Hibiscrub’ and ‘Surgiscrub’ were the least irritant and had the best visual appearance. Despite apparent similarities, these chlorhexidine formulations varied in acceptability to users.
Introduction
The hands of hospital personnel play an important role in the transmission of infection.lm3 Handwashing is one of the main methods for reducing cross-infection in hospital wards. Its effectiveness in reducing the spread of infection depends on several factors: the preparation used, the extent of contamination, the occasion of handwashing, the handwashing technique and the type and survival of the organisms present. The use of a product also depends on user acceptability, and any reluctance to wash hands could jeopardize the success of the aseptic procedure. ‘Hibiscrub’, ICI’s antiseptic handwash preparation containing chlorhexidine gluconate, has been used for many years in hospital wards, but there are now several similar products on the UK market, whose bacteriological efficacy has been tested and found to be adequate.4p5 This study was designed to compare the user acceptability of four antiseptic agents. All were pink, soapy solutions containing 4% chlorhexidine. Materials
and
methods
Seventy-three volunteers, who were not familiar with any of the products tested, were recruited into the study. Subjects with broken skin, eczema and known allergies to chlorhexidine or soap were excluded. 03954701/91/06B051
+OS $03.00/O
Q 1991 The Hospital
51
Infection
Socmy
D. Scott et al.
52
The four agents used were ‘Hibiscrub’ (ICI Pharmaceuticals), (Seaton Health Products) and ‘Macrocide’ (Macarthys), ‘Uniscrub’ ‘Surgiscrub’ (Ivex). Each agent was supplied in its original square 500 ml plastic bottle, which was entirely masked. The bottles were fitted with identical dispensers calibrated to deliver 4 ml per actuation. The code letters used to identify the preparations were changed each session to avoid volunteers biasing others by describing the products. Each volunteer used a different preparation on each of 4 days, within one following a standard protocol. The order in which 2-week period, preparations were used was randomized using a factorial design. The containers were weighed daily to determine the quantity of scrub used. Physicochemical properties of the agents were assessed (Table I). Handwashing procedure On each occasion, the hands were washed without scrubbing ten times over 9 h, allowing a minimum of 15 min between washes. Cold water was available for rinsing and paper towels for drying. The technique used was that which is taught to hospital staff. Acceptability assessments Volunteers were asked to assess the product they had used marking their responses on 100 mm visual analogue scales (VAS). These scales assess between the two extremes of bad (0 mm) to good (100mm). The factors assessed were: smell, appearance, feel, lather, ease of rinsing and itchiness. In addition, volunteers were asked if they would be prepared to use the preparation routinely, and to say which of the following adjectives could be applied to their hands: dry, soft, sore, normal, rough, sticky, clean. Laboratory lather tests for each product were performed to compare with volunteer assessments. A mixture of 5 ml of soap and 10 ml of tap water was shaken vigorously in a stoppered cylinder. The volume of lather produced was noted at 0, 5, 10, 15 and 30 min. Statistics VAS scores for each product were compared using the paired t-test. Probability values quoted are two-tailed with values less than 0,05 regarded as significant. Non-parametric tests, including the Wilcoxon signed rank test, confirmed the differences described by the t-test. Table
I. Physicochemical
Physicochemical Chlorhexidine Isopropanol PH Density Viscosity
property content
properties of the handwash in the study
formulations
Range of measured values 3.95-4.14%
C&6.4% 5.2-7.1 l.Ol-1.04gml-’
13.5-92.5 CS
used
User Table
acceptability II.
Index for measurement stickiness
of chlorhexidine
Assessment of the sensitivity
53
formulations of paired
VAS
scales
of ‘Betadine’
Soap
Weight of glass beads (mg) Mean VAS score (mm) Paired VAS score (p)
35
17
3
‘Hibisol’
‘Hibiscrub’
64 3 0.04
10
0.25
2460 43 0~0001
80
Smell
a
Feel Macrocide
Figure 1. Mean VAS scores Reproduced with permission.6
Look H
for
Uniscrub
perceived
Lather 0
properties
Surgiscrub of antiseptic
Rinsing m
Itchiness
Hibiscrub
handwashing
agents.
Sensitivity of paired VAS scales The sensitivity of paired VAS scales, as used in this study, was illustrated by a second study of similar design in 33 volunteers. The volunteers wore latex dental gloves for 2 h during which time they washed their gloved hands six times with either unmedicated soap, ‘Betadine’, ‘Hibiscrub’ or ‘Hibisol’. The stickiness of the gloves was measured by VAS scales, and by a standardized laboratory method which measured the weight of 180 pm Ballotini glass beads adhering to the gloves. Table II indicates the mean weight of beads taken up by each glove after using these preparations. Results
One volunteer withdrew from the study because of skin soreness. The mean quantities of the four scrubs used were not significantly different.
D. Scott et al.
54 Table
III.
Number
of positive responses to proposed adjectives describing following washing. Reproduced with permissionb Number ‘Macrocide’
Normal Clean Sore Rough Sticky
26 38 2 10 13
(36) (53) (3) (14) (18)
‘Uniscrub’ 18 40 4 14 13
(25) (56) (6) (19) (18)
the condition
of hands
(%) ‘Surgiscrub’ 32 (44) 45 (63) 3 (4) 3 (4) 11 (15)
‘Hibiscrub’ 26 (36) 40 (56) 0 (0) 6 (8) 8 (11)
The mean VAS scores are shown in Figure 1. ‘Uniscrub’ had the lowest mean VAS ratings for smell, and the difference from each of the other three products was highly significant (P< 0.003). There was a similar distinction with regard to feel, which was statistically significant to the same degree. ‘Macrocide’ and ‘Uniscrub’ both had lower scores for appearance than either ‘Hibiscrub’ or ‘Surgiscrub’ (P< 0.05). ‘Macrocide’ and ‘Uniscrub’ also showed a trend towards lower mean scores for itchiness, though this did ‘Macrocide’ and ‘Hibiscrub’ scored not reach statistical significance. highest for ease of rinsing, and ‘Hibiscrub’ had significantly higher lather ratings than the other products. ‘Uniscrub’ had the lowest rating for lather production. Laboratory measurements of the lather volume showed no differences between products. Two of the adjectives, soft and dry, were found not to be helpful descriptions of washed hands, because opinion as to their desirability varied. Results for the remaining five adjectives are shown in Table III. In reply to the question of whether volunteers would be prepared to use the product routinely, the most favourable response was obtained with ‘Surgiscrub’ (47%). Next came ‘Hibiscrub’ (4.5%), followed by ‘Macrocide’ (44%) and ‘Uniscrub’ (17%). Discussion
In order to reduce the incidence of cross-infection in hospitals, health care workers must wash their hands frequently and in the correct manner. Any reluctance to do so will render the antiseptic process ineffective. Clearly, the acceptability of antiseptic products to users is important and in practice, unpleasant or demanding protocols are not fully followed. This study detected differences in user acceptability between four antiseptic agents which all contained 4% chlorhexidine. Of the four agents tested, ‘Uniscrub’ was overall the least popular on the basis of VAS scores and direct questioning, while there was no clear distinction between ‘Macrocide’ and ‘Surgiscrub’. ‘Hibiscrub’ was the most popular preparation in terms of feel, appearance, rinsing, lathering and causing the least amount of soreness and roughness.
User acceptability
of chlorhexidine
formulations
55
The sensitivity of paired VAS scales was confirmed by the second study. The mean VAS scores merely identified the greatest difference between products, namely the stickiness of ‘Hibisol’ compared to soap. The VAS paired t-test, expressed as a probability of a difference from the use of soap, identified that difference and highlighted another, between ‘Hibiscrub’ and soap. Thus, paired VAS scales are a highly sensitive, and simple, method for comparing subjective properties that may or may not have an objective correlate. Laboratory tests on the physicochemical properties of the chlorhexidine scrubs (West Midlands Pharmacy Quality Control Laboratory) did not reveal any obvious causes of the variation in acceptability, despite measurable differences. All contained the stated quantity of chlorhexidine ( f 5 %) and were of similar density. The viscosities varied considerably, but the order of values did not match the order of acceptability for ‘feel’ or Two products (‘Hibiscrub’ and ‘Uniscrub’) contained ease af rinsing. isopropanol but the only property which appeared to be affected by that was smell. ‘Uniscrub’ had a very unpopular smell but Hibiscrub was not distinguishable from the non-propanol preparations. ‘Uniscrub’ also had the highest pH but it was not above the range which is typical of liquid soaps. It was interesting that a laboratory test for lathering capacity failed to predict the subjective responses of users accurately. It had been thought that poor lathering would result in an increased amount of soap used, but this was not the case. Potential users of antiseptic soaps should be consulted prior to the placement of large orders, as it is clear that decisions based purely on cost, antibacterial efficacy and technical information will not necessarily lead to adequate hand antisepsis.’ References 1. Maki
DG.
Control
of colonization
and transmission
of pathogenic
bacteria
in the hospital.
Ann Intern Med 1978; 89: 777-780. 2. Reybrouck G. Role of the hands in the spread of nosocomial infections. J Hosp Infect 1983; 4: 103-110. 3. Maki DG. The use of antiseptics for handwashing by medical personnel. J Chemother 1989 1: (Suppl): 3-11. 4. Ayliffe GAJ, Babb JR, Davies JG & Lilly HA. Hand disinfection: a comparison of various agents in laboratory and ward studies. J Hosp Infect 1988; 11: 226-243. 5. Lee MG, Hunt P, Felix D. A comparison of two bactericidal handwashing agents containing chlorhexidine. J Hasp Infect 1988; 12: 59-63. 6. Scott DK, Lister MR. An evaluation of the user-acceptability of four surgical scrubs.
PharmJ 7. Ayliffe
1990; 245: 120-121. GAJ.
Standardization
of disinfectant
testing.
J Hosp Infect 1989; 13: 211-216.