Acceptance of semipermeable glove liners compared to cotton glove liners in health care workers with work‐related skin diseases: Results of a quasi‐randomized trial under real workplace conditions

Glove liners (GLs) made of cotton (COT) are worn under impermeable gloves to prevent occlusion effects. Semipermeable GLs made of Sympatex (SYM) might be an alternative.


| INTRODUCTION
Health care workers (HCWs) are at risk of developing work-related skin diseases (WRSDs) primarily due to a high amount of wet work and repeated exposure to irritants (eg, cleansers, detergents, and disinfectants). 1,2 The most common WRSD is hand eczema, with a 1-year prevalence of about 20% in HCWs. 3,4 Wearing of protective gloves is mandatory in health care to avoid exposure to occupational hazards, including pathogenic germs. [5][6][7][8][9][10] These gloves usually consist of (water-)impermeable materials (rubber or plastic), which induce occlusion effects by inhibiting the evaporation of skin moisture and by heat accumulation. A recent review stated that especially longterm occlusion, extensive wearing of gloves (6 hours/day for >10 days), additional exposure to hazardous substances, as well as occlusion of pre-irritated skin may lead to severe impairment of the epidermal barrier function. 11 Glove liners (GLs) are defined as a separate glove-like hand covering made of cotton (COT) or other natural (eg, wool) or synthetic fibers with different material strength/thickness. They are recommended to be worn underneath occlusive protective gloves in case of "long" wearing times or activities lasting >10-15 minutes to counteract the effects of glove occlusion. 6,7,[12][13][14] Textile GLs absorb moisture by a hygroscopic effect. Moreover, gloves made of COT are used in patients with hand lesions as cover or support of topical treatment. However, studies evaluating the use of GLs are scarce. In a few intervention studies based on health education, the use of COT-GLs were recommended as part of complex programs developed for primary or secondary prevention of WRSDs in high-risk occupations, but their practicability or effectiveness were not evaluated separately. [15][16][17][18] GLs made of semipermeable synthetic materials might be an alternative to COT-GLs. They enable permeation of moisture (vapor of human sweat) along the diffusion gradient on a molecular level. Moisture remains in the gap between the semipermeable GL and the impermeable protective glove and leaks out via the cuff by movements of the hands during glove use. Investigations conducted with the semipermeable Gore-Tex membrane (W. L. Gore and Associates, Unterföhring, Germany) focused on its effects as wound dressing, 19 on skin barrier regeneration after irritation, [20][21][22] and on prevention of allergic contact dermatitis from rubber accelerators. 23,24 Previous experimental and small-scale cohort studies under real workplace conditions of our research group showed that the 15 μm thin semipermeable polyesterpolyether Sympatex (SYM) membrane (Sympatex Technologies GmbH, Unterföhring, Germany) reduces the occlusion effects of impermeable protective gloves and prevents skin barrier impairments. [25][26][27][28] The results indicated a cross-occupational suitability of SYM-GLs with regard to user acceptance (especially tactility and sweating sensation) and a preference over previously used protective gloves or glove combinations. 28,29 However, similarly to the COT-GLs, no systematic evaluations have yet been carried out for GLs made of semipermeable materials with regard to their acceptance in everyday work.
Therefore, the aim of this study was to determine the user acceptance of SYM-GLs in direct comparison to COT-GLs and to answer the following research questions: (1) For which activities are GLs suitable?
(2) How does the use of occlusive gloves in combination with either SYM or COT-GLs differ from the use of occlusive gloves without GLs?
(3) Are there differences in the usability of SYM and COT-GLs?

| Study design and materials of glove liners
For this cross-sectional study, the participants were assigned to one of the two study cohorts according to a randomized scheme determined in advance by the study coordination. Recruitment alternated weekly for the SYM cohort and the COT cohort; in half of the centers, recruitment alternated in reverse order. Accordingly, entire seminar groups of HCWs were equipped with either COT or SYM-GLs in alternation to avoid cross-contamination by communication between participants. During the SIP, the participants tested the GLs to ensure a good fit when wearing them underneath the selected occlusive protective gloves. Each study participant received 50 pairs of COT-GLs

| Questionnaire
After the 3-month application phase, all study participants were asked to fill out an anonymous modularized questionnaire, which was sent to the participants by mail including a cover letter and a prepaid return envelope. In case of nonresponse, two reminders were sent at The questionnaire included the standardized recording of sociodemographic characteristics (eg, age, gender, occupation) and an evaluation of the wearing behavior of the GLs with regard to various variables. The participants were asked to rate the practicability for the activity they most frequently performed with the GL during the study period, and to compare the newly tested glove combination with the gloves or glove combinations they previously used (previously used protective glove; PUG) to use for this activity. In the first step, several statements were evaluated according to a 5-point Likert scale for agreement/satisfaction (1 = strongly agree, 2 = agree, 3 = neither agree nor disagree, 4 = disagree, 5 = strongly disagree) (eg, "The climate under the gloves is pleasant.") ( Table 5). The basis of the final evaluation (eg, "sweating sensation") was a 6-point scale based on the German school grading system consisting of six numerical grades (1: very good, 2: good, 3: satisfactory, 4: sufficient, 5: poor, 6: very poor) ( Table 6). We chose this scale because all participants are familiar with these categories. In addition, the respondents were asked to rate their own skin condition at the beginning (retrospectively) and the end of the test phase on a 10-level scale (0 = none, 10 = severe skin changes). SYM: n = 65, 77.4%; COT: n = 55, 71.4%) but to an improved comparability of data. Table 3 shows the participants' characteristics in detail.

| Data analysis
Most of those who returned the questionnaire but indicated that they had not tested the GLs for at least 8 weeks, provided a reason  forgetfulness (n = 1). In the COT cohort (n = 8/63), the following reasons were given: improvement of skin condition (n = 2), lack of sensitivity (n = 2) and other (holiday, deterioration of skin condition, absenteeism from work due to pregnancy, no need, sick leave, lack of support at the workplace/no permission from the employer to use COT-GLs, laziness; each n = 1).
In order to exclude systematic distortions in the sample, a dropout analysis was performed regarding gender, age, and occupation, which were the only variables collected during initial recruitment. No significant differences were found between drop-outs and those who tested the GLs for at least 8 weeks within the SYM cohort (n = 10 vs 65) and the COT cohort (n = 8 vs 55) with regard to gender, age, and occupation.
There were no statistically significant differences with regard to "suitability for everyday use" and "wearing comfort" between SYM and COT-GLs (Tables 5 and 6). Both the COT and the SYM-GLs combinations were rated as "good" (mean = 2.3) in the overall evaluation (n.s.). In addition, most individual categories (eg, sweating) were rated "good" for both GLs (Table 6).

| Usability and glove type preferences
The "suitability for daily use" of both GLs was found to be "good" (Table 6). More than two thirds of the respondents in both cohorts

| DISCUSSION
To the best of our knowledge, this is the first application study comparing the use of GLs made of COT or a semipermeable membrane under real working conditions. In terms of wearability in everyday working life and suitability for everyday use, both GLs received good ratings in this cohorts of HCWs with WRSDs, suggesting that their use underneath occlusive gloves is not a disadvantage. On the contrary, most items in terms of user acceptance were rated better compared to the use of protective gloves without GLs. A big majority in both groups reported that they were able to perform everyday occupational activities as usual when wearing the GLs (SYM: 87.3%; COT: 88.3%).
Both types of GLs were frequently used in typical occupationspecific activities, such as basic care in hospital/geriatric nurses, massages in physiotherapists, and chairside assistance in dental assistants.
This was in line with other studies showing a good general acceptance of textile [33][34][35] and semipermeable 33 GLs. The average daily consumption of SYM-GLs with 9.0 pairs/day was significantly higher than in the COT cohort, with 4.6 pairs/day (P < .001). This suggests that COT-GLs wereagainst our study instructionsworn more than once, whereas SYM-GLs were used only once as instructed, raising obvious hygiene issues in hospital settings for COT-GLs.

| Climate conditions
The use of GLs made of either SYM or COT underneath occlusive gloves was rated superior to the use of occlusive gloves without GLs regarding all climatic parameters. COT-GLs absorb moisture caused by sweating, whereas SYM-GLs enable permeation of moisture caused by sweating along the diffusion gradient to the outer side of the membrane. 36 Thus both mechanisms reduce moisture accumulation within occlusive gloves. Accordingly, the results of the present study indicate that GLs keep the hands dry(er) even when occlusive gloves are worn for long periods and reduce the feeling of moisture and uncomfortable warmth underneath occlusive gloves. The sweating sensation was lower for both types of GLs compared to PUGs without GLs despite the second glove layer. This is consistent with data from a 5-day halfside wear test of SYM-GLs in employees from different occupational areas (n = 72). 29 In that study, a more pleasant skin climate and reduced sweating sensation was reported for the use of SYM-GLs underneath occlusive gloves compared to wearing occlusive gloves without the GLs. In addition, others found reduced sweating sensation under a single semipermeable glove compared to impermeable glove models in short-term wearing trials. 25,26 The results of these studies were corroborated by skin bioengineering and are consistent with the study by Sonsmann et al. 28 In the present study, the sensation of sweating, climate, and feeling of dry skin (even when wearing occlusive gloves for a long time) was rated better for SYM-GLs than COT-GLs. In line with this, participants in the study by Baack et al. also indicated a cooler and drier feeling with less itching for wearing of semipermeable GLs compared to COT-GLs . 33 Hygroscopic natural COT fibers are known for their water absorption capacity, but also for their swift material saturation. Therefore, the use of COT-GLs in comparison to SYM-GLs seems more appropriate for a shorter duration of wearing occlusive gloves, since longer wearing times lead to an exhaustion of the moisture-reducing effect of COT. Thus SYM-GLs may be superior to COT-GLs when long continuous glove wearing is necessary.

| Skin feel and wearing comfort
The wearing comfort and material feel on the skin was rated significantly better for use of both types of GLs underneath occlusive gloves than PUGs worn without GLs. All study participants reported an improvement of their skin condition over the study period. In a small preliminary study by Hübner et al., which examined the use of COT-GLs in medical staff (n = 18) of an intensive care unit over a 3-month period, the wearing comfort of COT-GLs was perceived predominantly as (very) pleasant (43.7%). 34 Other studies have also shown that COT-GLs are beneficial for maintaining a good skin condition and comfort. 34,35,37 There were no significant differences between use of SYM and COT-GLs in terms of wearing comfort and material feel on the skin. In direct comparison, however, a higher share of participants in the COT group attributed the improved skin condition (in part) to the use of GLs. However, this difference was not significant. In con-

| Mobility and tactility/fine motor skills
The function of the hands could already be impaired by wearing the protective glove alone. 41,42 Therefore, GLs should ideally not further decrease sensory and motor functions of the hands. Impairments of hand mobility (eg, when executing targeted movements) and sensitivity were exclusively indicated by the participants for the use of COT-GLs underneath occlusive gloves compared to PUGs without GLs.
This is in line with other studies showing a better tactility for semipermeable gloves compared to COT-GLs. 33,39 The lower tactility is probably related to the thick material of COT-GLs, which impairs activities for which a high tactility or a firm grip is required. 37,[43][44][45][46] In contrast, SYM-GLs have an $5 times lower material thickness of 15 μm than COT-GLs. Furthermore, tactile properties of textile GLs are negatively influenced by circumferential seams, 47,48 which is why COT-GLs should ideally be round-knitted rather than woven and sewn. 34,49 The present results are consistent with those of the study in HCWs of an intensive care unit by Hübner et al., in which the sense of touch was rated predominantly "satisfactory" (47.9%) when wearing COT-GLs and predominantly "good" (58.3%) when using protective gloves without COT-GLs. 34 In that study, GLs were preferably worn for activities where tactility/sensitivity were of minor importance (86.8%), for example, positioning or mobilization of patients and general activities on the patient. 34 Activities that required higher fine motor skills were rarely performed with GLs (3%), for example, treatment procedures involving change of wound dressings. 34 As the majority of occupational activities performed by HCWs require a high degree of sensitivity/tactility, the use of SYM-GLs may be superior to the use of COT-GLs. However, regular practice with GLs may lead to habituation and reduce the noticeable impairment of manual dexterity or tactile sensation. This "habituation effect" has already been demonstrated in studies on double-gloving of occlusive protective gloves. 50 If there are still restrictions in tactility, use of fingertip-free or completely fingerless COT gloves can be considered. 34,51,52 However, these cannot counteract negative occlusion effects at the fingers or fingertips.

| Fit, appearance, and donning and doffing
The SYM glove received significantly lower rates compared to PUGs regarding fit and appearance, which corresponds to a previous study. 29 No significant differences were found between COT-GLs and PUGs. In direct comparison, the SYM-GLs was rated lower than the COT-GLs in terms of fit, which can be explained by the twodimensionality of the SYM-GLs. A tight-fitting protective occlusive glove worn on top of the SYM glove can take on a formative function (influence the fit). 26 Because the SYM glove is used exclusively as a GL, also the worse rating of the appearance plays a subordinate role.
The donning and doffing behavior of occlusive gloves in combination with SYM-GLs was rated significantly lower compared to PUGs without GLs, whereas use of COT-GLs scored better compared to PUGs without GLs. In addition, the "donning and doffing" behavior of SYM-GLs was rated significantly worse compared to COT-GLs. The COT material of the GLs prevents adherence of the protective glove to moist skin, which facilitates putting on the protective gloves in everyday work. In addition, in the study by Hübner et al., putting on and taking off COT-GLs was considered unproblematic. 34 The additional time required was classified as low (58.3%) or not perceived (12.5%).
In contrast, the polyester-polyether SYM membrane generates more friction under protective gloves (eg, made of nitrile), which may render it more difficult to put on the protective gloves. Reasons for the problems with SYM-GLs given in the free text fields included difficulty of sticking of the glove cuff (n = 6) or presence of moist hands (eg, due to sweating, previous creaming, cleansing, or disinfection) (n = 4) when putting on gloves (À contrary to our clear instructions given to the participants prior to the study to use GLs only on dry skin).

| LIMITATIONS
The study was conducted in HCWs with WRSDs who likely have a distinct skin protection behavior or a specific motivation to implement new skin protection measures (eg, use of GLs). Therefore, the results cannot be transferred to HCWs without WRSDs or other occupational groups. Because some of the participants had already used textile GLs prior to the study, the evaluations of the GLs in the study cannot be considered completely detached from these previous experiences. Moreover, self-reported data may be incorrect and may contain several potential sources of bias, for example, selective memory. Some participants dropped out of the study because they indicated that they had not tested the GLs for at least 8 weeks. This may have led to selection bias with overestimating of the benefits of GLs. However, mainly practical reasons, often not related to the GLs themselves, were given and the drop-out analysis did not reveal major differences to the participants included in the analyses. Open access funding enabled and organized by Projekt DEAL.