How does washing without water perform compared to the traditional bed bath: a systematic review

A systematic literature search was executed in CINAHL, Embase, MEDLINE and PUBMED to collect controlled trials about the effectiveness of the washing without water concept. Studies published before 1995 were not included in the literature search, because only in that year the first article about the bag bath concept was published. Since the washing without water concept does not yet have a commonly accepted generic name, many combinations of adjectives and nouns were used that could represent the concept. Search terms were determined based on the key terms used in literature about washing without water to describe the concept. Identical terms as well as synonyms were used. Furthermore, no specific search terms regarding health care setting, type of patients or outcomes were included as we were interested in all effectiveness outcomes of washing without water for immobile patients in all settings. The search terms and filters used in the different databases are shown in Additional file 1. No language limiters were applied in any of the searches. The database search was executed at two points in time. The first search was performed in May, 2015, and in February, 2016, the search was updated. In the second search of February, 2016, only studies published after the date of the first search were retrieved from the databases. Both database searches consisted of two search runs. In the first search run, only studies labeled as a trial were obtained by using the trial filter. The second search run combined the search terms of the first search run with the search term ‘trial’ using the Boolean operator ‘AND’ and without using the trial filter to ensure that all trials were included in the search results. Additional studies were identified by screening references and by citation searching of the articles screened for full text. Finally, the list of studies was presented to experts in the field of washing without water to ensure that all relevant studies were included. These experts included an author of a previous study related to washing without water, and an infection prevention specialist who is knowledgeable about washing without water.

Studies were eligible if (1) the study designs included outcomes of washing without water products developed for the full body wash compared to the traditional bed bath, and (2) they were controlled trials. Conversely, studies about products specifically developed for other purposes than the regular body wash, such as incontinence care or disinfection, were excluded. Interventions that are related to washing without water but are excluded in this study are presented in Table 1, together with the reasons for exclusion. Finally, no criteria were determined regarding type of patients, nursing staff or health care settings to collect all evidence on outcomes of washing without water.

Studies were consecutively screened on title, abstract and full text for eligibility. To reduce bias, titles and abstracts were independently screened by two researchers (first author and MM) until the level of agreement between them exceeded 80%. From that moment, the remaining studies were screened by the first author alone. Studies were recorded as either “include”, “exclude” or “uncertain”, and disagreements between the researchers were discussed to reach consensus. Studies labelled as “include” or “uncertain” were included in subsequent stages of the screening process. Full text screening was done only by the first author. In case of doubt, the first author discussed the full text with one of the other authors (SZ), after which a collaborative decision was made to include or exclude the study.

Data were extracted from the relevant articles using a data extraction form specifically designed for the current review. This form included items needed for the quality assessment of the eligible studies such as items about the research design, study populations, type of interventions, study aims, statistical analyses, outcomes, and recommendations and limitations. For two articles, which lacked information regarding these items, the particular authors were contacted to retrieve additional data or the study protocol. Only one of these authors agreed to share the protocol.

Out of an inventory of several methodological quality assessment tools, the scale of Downs and Black [22] was selected to calculate a total quality score (Table 2). This scale is one of the most complete assessment tools and covers most risks of bias as described in the Cochrane Handbook for Systematic Reviews of Interventions [23]. Furthermore, the Agency of Healthcare Research and Quality (AHRQ) argues that the Downs and Black [22] scale is rigorously developed [24]. The original two items regarding blinding of persons receiving the intervention and of persons providing the intervention were not applied because this was considered to be practically impossible with the washing without water intervention. Furthermore, the scoring possibilities for the items related to the sample size and the description of principal confounders were adapted for this research (see Table 2). Two researchers (first author and HB) independently assessed study quality and discussed disagreements to reach consensus. When consensus was not reached, the particular items were discussed with one of the other authors (SZ). Based on the quality domains defined by the AHRQ, five items from the Downs and Black [22] scale were selected as representing the most important quality requirements. These items are related to the study aim description (item 1), statistical tests (item 16), randomization (item 21), intention-to-treat (item 23), and statistical power (item 25). In this review, a study was considered to be of high quality if it met all five of these items. If a study did not meet all of these criteria, it was considered to be of moderate quality.

An overview of the evidence related to all washing without water outcomes was made. We categorized findings on the effectiveness of washing without water in (1) physiological outcomes related to hygiene and skin condition, (2) stakeholder-related outcomes, and (3) organizational outcomes. All results of the studies of moderate or high quality are presented.

Figure 1 shows the results of the screening process. The numbers of studies mentioned in the figure are the totals of the articles retrieved in May, 2015, and February, 2016. Of the 1,830 unique studies that were retrieved from the electronic database search, ultimately, six studies were included in this review. The main reason for exclusion was that the intervention in the particular studies was not a washing without water product.

Information regarding the characteristics of all included studies is provided in Table 3. The studies employed different study designs, including three randomized controlled trials [2, 25, 26]. The studies of Schoonhoven et al. and van Achterberg et al. were based on the same research data [2, 25]. Two other studies applied a controlled cross-over design over two consecutive days in which all subjects received the traditional bed bath on 1 day and a bed bath with a washing without water product on the other day [27, 28]. The order in which subjects received the different bed baths was randomized in only one of these studies [28]. The last study had a quasi-experimental design [29].

Moreover, research settings and populations also differed between the studies. Two studies [27, 28] were conducted in a hospital, and four [2, 25, 26, 29] took place in institutionalized long-term care. Furthermore, the four studies conducted in institutionalized long-term care only included residents aged 65 years or older (the average ages ranged from 82.4 to 85.17 years), whereas the two studies situated in hospitals also included patients younger than 65 years (leading to average ages of 73 [28] and 60.7 [27] years). Information regarding cognitive impairment as a feature of the study population was only reported in three studies [2, 25, 29], the details of which are mentioned in Table 3. The study by Nøddeskou et al. [28] excluded cognitively impaired patients, whereas the other two studies did not mention cognitive impairment as an exclusion criteria nor did they report on the presence of such patients [26, 27].

Information about the quality assessment of the studies can be found in Table 2. Only the studies by Schoonhoven et al. and van Achterberg et al. met all five of the primary quality items and were therefore considered to be of high quality [2, 25]. These studies also received the highest total quality scores of all included studies (21/25). The other four studies were considered to be of moderate quality. Of these four, the study of Gillis et al. [26] did obtain a high total score, but was not considered to be of high quality as it did not meet all of the five primary quality items (4/5). Due to the small number of studies, all studies of moderate to high quality were included in the data synthesis. Furthermore, because only a limited number of studies was found and the reported outcomes varied considerably between studies, it was not possible to assess the risk of bias across studies nor to conduct a meta-analysis.

Table 4 shows a complete overview of the results per included study. Skin hydration [26], any skin abnormalities, significant skin lesions [2], reduction in microbial counts [27], and skin dryness [29] were categorized as physiological outcomes. Resident satisfaction [2, 29], nurse satisfaction [2, 27‐29], bathing completeness [25], and resistance during bathing [2] were regarded to be stakeholder-related outcomes. Finally, organizational outcomes were costs (including staff wages and material costs) [2, 27, 28], time of a bed bath [27, 28], and the quality score of the bed bath [27, 28].

Outcomes related to hygiene and skin condition are regarded to be physiological outcomes of washing without water in this review. The high quality study by Schoonhoven et al. [2] measured outcomes related to residents’ skin condition, being any skin abnormalities and significant skin lesions. If the skin of certain parts of the body was not intact, the severity of the skin lesion was considered to be significant, whereas skin abnormalities included, amongst others, erythema and skin discoloration. A significant difference in the prevalence of skin abnormalities over time (6 weeks) was observed between the washing without water group, in which the prevalence decreased, and the traditional bed bath group, in which the prevalence increased. However, no significant difference was found regarding the occurrence of significant skin lesions over time. Other findings related to the skin condition were presented in the studies of moderate quality from Sheppard and Brenner [29] and Gillis et al. [26]. The results of Sheppard and Brenner [29] showed a significant difference between the washing without water group and the traditional bed bath group regarding skin dryness in favor of washing without water. Furthermore, Gillis et al. [26] concluded that skin hydration at the cheek increased significantly more when washing without water was adopted compared to the traditional bed bath. No differences were found for skin hydration at hands or legs. Physiological outcomes related to hygiene were only reported in the study of moderate quality by Larson et al. [27], where no significant differences were found.

Next to physiological outcomes, stakeholder-related outcomes are considered to be important in this review. In a study of high quality, Schoonhoven et al. [2] reported a resident satisfaction score of 7.1 (out of 10) and a nursing staff satisfaction score of 7.5 for washing without water. However, they did not compare satisfaction regarding washing without water with the level of satisfaction regarding the traditional bed bath. Also Sheppard and Brenner [29] studied resident and nurse satisfaction without comparing the level of satisfaction between the two bathing methods in their study of moderate quality. A comparison of nursing staff satisfaction was made in the studies of moderate quality by Larson et al. [27] and Nøddeskou et al. [28]. Nursing staff in both studies significantly preferred washing without water over the traditional bed bath. The high quality study outcomes “bathing completeness” and “resistance during bathing” are also considered to be stakeholder-related outcomes in this review. Bathing completeness was found to be significantly higher for washing without water compared to the traditional bed bath [25]. Finally, no significant treatment by time interaction was found regarding resistance during bathing, which means that residents bathed with washing without water did not show more or less resistance compared to residents bathed the traditional way [2].

Finally, several findings related to organizational outcomes of washing without water compared to the traditional bed bath were reported. The only study of high quality that reported on costs did not find a significant difference in the total average costs over a time period of 6 weeks between washing without water and the traditional bed bath [2]. In two other studies of moderate quality, the average total costs of a bed bath were reported to be DKK 106.25 [28] and $18.15 [27] for washing without water and DKK 126.96 and $19.87 for the traditional bed bath, respectively. An important costs component is the nursing time spent on the bed bath. The complete time from preparation of the bed bath to clean-up was only studied in one study of moderate quality in which a significant difference was found both in the total bed bath time and in the time of all individual stages of the bed bath, which were all shorter for washing without water (p < 0.001) [28]. No significant time difference was found in the study of moderate quality of Larson et al. [27], who did not include the time needed for preparation and clean up. Finally, the quality of the bed bath was measured in two studies of moderate quality in which no difference between the two bathing methods was found [28, 29].

Reflecting on the evidence on washing without water, we yield some noticeable findings. First, none of the studies included all cost components in the cost calculation. For example, Schoonhoven et al. [2] did not include the time that nursing staff spent cleaning up after the bed bath. Because nursing time is an important cost component related to the bed bath, substantial costs may not have been included in the cost calculation. Second, patient satisfaction between washing without water and the traditional bed bath has not been compared in any of the included studies, which is interesting given the growing attention for patient-centered care. The Institute of Medicine defines patient-centered care as care that suits patients’ needs and preferences [30]. Consequently, patient-centered care is argued to contribute to patient satisfaction [31]. The scarce evidence regarding the effect of washing without water on patient satisfaction could be explained by the output-oriented management approach in health care. From an output perspective, the bed bath is merely provided to reach cleanliness [32]. However, evidence on the effectiveness of washing without water regarding hygiene is also still scarce, as it is measured in only one of the included studies [27].

Finally, washing without water is increasingly used in health care institutions, while the evidence on washing without water in general, and on hygiene and patient satisfaction in particular, is limited. Thoma-Lürken et al. [1] also conclude that the effectiveness of many implemented health care interventions, such as washing without water, need to be further assessed. One could take the argument of Feo and Kitson [32], that bathing is often perceived as a low-priority nursing task, to explain the lack of evidence regarding washing without water [19, 33]. However, the number of studies about bathing and hygiene that we encountered while conducting this review demonstrates that the nursing field is highly interested in patient hygiene. Therefore, we encourage nurse researchers to actively cooperate with clinical researchers to conduct more trials of high quality that inform nursing staff on how to provide the best possible care, and consequently, to upgrade the perceived value of fundamental care [32].

The scarce evidence regarding washing without water in general, and regarding washing without water outcomes related to costs, hygiene and patient satisfaction in particular, calls for additional research. Although costs were measured in half of the included studies [2, 27, 28], not all costs were included in the measurements. A complete cost overview would contribute to the burden of proof regarding the cost-effectiveness of both bathing methods. Furthermore, the only study that reported on hygiene outcomes did not find a significant difference in total microbial counts from the groin or the umbilicus after the bed bath between washing without water and the traditional bed bath [27].

From a patient-centered care perspective, patient-related outcomes should be studied more elaborately, including patient satisfaction, patient experiences, and patients’ value perceptions regarding washing without water. According to Berwick [34], patient experiences lie at the heart of quality of care. The focus on patient experiences is consistent with patient-centered care and is likely to contribute to patient satisfaction [31]. Patient experiences are not only related to patient satisfaction and to quality of care, but also to the patient’s perceptions of the value of care [35]. For washing without water, this means that patients evaluate the value of the washing without water bed bath based on their experiences with it.

However, the patient is not the only stakeholder involved in the bed bath. The nursing staff is another important stakeholder group. Nursing staff may decide whether or not to use a washing without water product without providing the patient a choice. Moreover, family members are important stakeholders as they generally are highly involved in health care, especially when patients are old and vulnerable. Different stakeholders have diverse perceptions of value depending on their individual needs and contexts [36]. For example, patients might derive value from the experience of having soft skin, whereas the nursing staff might derive value from giving an emotionally and physically burden-free bed bath. Hence, not only should future research on washing without water consider bed bath experiences of patients, but it should also consider bed bath experiences of other stakeholders, such as nursing staff and family. Moreover, it should take into account stakeholders’ different value perceptions of washing without water.

Based on the importance of experiences and value perceptions of patients, nursing staff, and family members, another recommendation for future research is to study the relationship between the outcomes of washing without water which can be measured objectively, on the one hand, and stakeholders’ experiences and value perceptions on the other hand (e.g. by adopting a mixed method approach). For example, one of the outcomes of washing without water is that it is more time-effective compared to the traditional bed bath. We do not know whether this has a positive or a negative effect on the patients’ or nursing staff’s experiences of the bed bath. On the one hand, a shorter bed bath can be less burdensome and therefore positively affect experiences and value perceptions of patients and nursing staff. Moreover, time-effectiveness of washing without water might be positively related to bathing completeness as argued by van Achterberg et al. [25]. On the other hand, patients and nursing staff might perceive a shorter bed bath as being impersonal and therefore a reduction in bed bath quality [2]. By elaborately examining patients’ and nursing staff’s experiences, valuable information can be obtained about the importance of washing without water outcomes for the experience and the value perceptions of patients and nursing staff.

Finally, this review points to two methodological implications. First, future research is needed to come to credible generalizations about the effectiveness of washing without water. The two studies of high quality were conducted in an institutionalized long-term care setting. Therefore, especially for outcomes that are unique to these studies, such as bathing completeness [25] and skin abnormalities [2], it would be interesting to study the outcomes of these studies in other settings as well. Furthermore, while three of the included studies included patients with cognitive impairments [2, 25, 29], and one study excluded cognitively impaired patients [28], two studies did not report on the presence of such patients [26, 27]. Hence, it is unclear whether results of the studies that excluded cognitively impaired patients are generalizable to settings where these patients are present. The inclusion of cognitively impaired patients in half of the included studies demonstrates that washing without water might be particularly valuable for this patient population. Second, many different outcome measures have been used in the included studies and the internal validity is not always described. The use of outcome measures with high internal validity would enhance the reliability of guiding evidence related to bathing practices, such as washing without water.

Two limitations of this study are related to the quality assessment of eligible studies adopted for this review. First of all, the Downs and Black [22] quality checklist does not provide a cut-off value that can be used to distinguish high quality studies from studies of lower quality. Hence, we selected five key criteria that needed to be met to be qualified as a study of high quality. The selection of other key criteria might have led to different quality assessment results. However, since all results of studies of moderate to high quality were included, we did not miss important outcomes regarding the effectiveness of washing without water. The second limitation regarding the quality assessment is that we did not assess the risk of reporting bias. We only asked authors of eligible studies for the study protocol in cases where information that we needed for the quality assessment was missing. We did not compare the study protocols of all included studies with the published results and therefore, were unable to assess whether authors did report on all intended outcomes. Moreover, the classification of outcomes as physiological, stakeholder-related or organizational is based on our own judgment. Although this classification is arbitrary, we did not miss important outcomes as all reported outcomes are included in one of the outcome groups.

To our best knowledge, the current study is the first systematic review of washing without water. This review provides a complete overview of the evidence on washing without water as we included all controlled trials irrespective of the outcomes studied, type of patients or health care setting. Our eligibility criteria are based on a restricted definition of washing without water, excluding bathing concepts and products such as the bag bath concept and antibacterial wipes. Furthermore, studies that did not adopt a controlled trial design were excluded from this review. Although some may consider that our chosen criteria limit the search results, we consider the criteria to be a strength of this study. By excluding concepts such as the bag bath, we assured that the results were related to the exact same intervention, being washing without water. In our opinion, the inclusion of related but distinct concepts would have clouded the results. Moreover, we argue that the inclusion of non-controlled trials would have weakened the results.