Abstract: We included 13 trials with 1316 participants in a qualitative synthesis. Participants were incontinent for urine, stool, or both, and were residents in a nursing home or were hospitalised. Eleven trials had a small sample size and short follow-up periods. .The overall risk of bias in the included studies was high. The data were not suitable for meta-analysis due to heterogeneity in participant population, skin care products, skin care procedures, outcomes, and measurement tools. Nine trials compared different topical skin care products, including a combination of products. Two trials tested a structured skin care procedure. One trial compared topical skin care products alongside frequencies of application. One trial compared frequencies of application of topical skin care products. We found evidence in two trials, being of low and moderate quality, that soap and water performed poorly in the prevention and treatment of IAD (primary outcomes of this review). The first trial indicated that the use of a skin cleanser might be more effective than the use of soap and water (risk ratio (RR) 0.39, 95% confidence interval (CI) 0.17 to 0.87; low quality evidence). The second trial indicated that a structured skin care procedure, being a washcloth with cleansing, moisturising, and protecting properties, might be more effective than soap and water (RR 0.31, 95% CI 0.12 to 0.79; moderate quality evidence). Findings from the other trials, all being of low to very low quality, suggest that applying a leave-on product (moisturiser, skin protectant, or a combination) might be more effective than not applying a leave-on product. No trial reported on the third primary outcome 'number of participants not satisfied with treatment' or on adverse effects. Little evidence, of very low to moderate quality, exists on the effects of interventions for preventing and treating IAD in adults. Soap and water performed poorly in the prevention and treatment of IAD. Application of leave-on products (moisturisers, skin protectants, or a combination) and avoiding soap seems to be more effective than withholding these products. The performance of leave-on products depends on the combination of ingredients, the overall formulation and the usage (e.g. amount applied). High quality confirmatory trials using standardised, and comparable prevention and treatment regimens in different settings/regions are required. Furthermore, to increase the comparability of trial results, we recommend the development of a core outcome set, including validated measurement tools. The evidence in this review is current up to 28 September 2016.

Plain-language summary: We included randomised controlled trials which compared skin care products, procedures, methods for using skin care products and frequencies of using a skin care product. The participants had to be over 18 years of age. We found thirteen, mostly small, trials, involving 1316 participants. All participants were incontinent for urine, stool, or both and lived in nursing homes or were hospitalised. The trials tested skin care products, procedures, and frequencies of using a skin care product. Two trials showed that soap and water performed poorly in the prevention and treatment of IAD. A skin cleanser or a washcloth with cleansing, moisturising and protecting properties may be more effective than soap and water. The findings from the other trials suggest that using a skin care product is more effective than withholding a skin care product. We found no evidence that one skin care product performed better than another. The trials did not report on adverse effects. The quality of the evidence was low. Eleven trials had small numbers of participants and were of short duration. The overall risk of bias was high. The trials included in this review tested skin care products, procedures and frequencies of using a skin care product. Very limited evidence exists on the effects of interventions for preventing and treating IAD in adults. Larger, long-term and well performed trials are required. Furthermore, we recommend the development of a list of outcomes which are important for patients and will guide researchers in their study. This list should include well developed tools to measure the items in order to obtain accurate results. The review authors searched for studies that had been published up to 28 September 2016.