Children and adolescents who are severely physically ill and require hospitalisation represent a special responsibility for the health care system and the people working in it for a number of reasons: In addition to the illness itself, the young patients are also stressed by the separation from their parents, the strange environment, the fear of painful treatments and/or the uncertainty of the treatment outcome e.g. [1, 2]. Hospital clowns, also known as clown doctors, can help paediatric patients with these stressors and to circumvent the accompanying feelings of fear, helplessness and sadness, thus supporting the healing process. They can be friends in need who help to bear a difficult situation more easily or simply offer a welcome distraction from the ward routine e.g. [3, 4].
Hospital clowning was developed in 1986 in the United States by Michael Christensen, a co-founder of the New York-based Big Apple Circus, and spread quickly from there throughout Europe. The first German association of clown doctors was founded in 1994 by a student of Christensen’s named Laura Fernandez. In the meantime, according to estimates of the umbrella organisation “Clowns für Kinder im Krankenhaus Deutschland e. V.” [Clowns for children in hospitals Germany], founded in 2004, there are roughly 250 hospital clowns working around the country. Most of them are members of one of the approximately 40 regional associations and work not only in hospitals but in dialysis centres, children’s hospices or paediatric emergency rooms. The specific work of a clown can be described well by three different role models: (1) the entertainer uses the performing arts, e.g. magic/sleight of hand, (2) the auguste, who makes children laugh using humour and slapstick acts, and (3) the clown as an ally who offers the child emotional support .
The mode of action of hospital clowning can be specified at four different levels of impact (see also [3, 6–10]). At the physiological level, laughing stimulates and modulates the immune system via the release of endorphins. At the emotional level, laughing replaces negative feelings with positive ones. At the cognitive level, the performance distracts the patient from his own situation, fosters imagination and supports the learning of new ways to express oneself. At the social level, laughing creates a connection between the children and clowns and stimulates further interaction. For each of the four levels of impact, there are an entire series of independent studies in which specific aspects were empirically tested and the corresponding hypotheses regarding the modes of action were confirmed (e.g. , on laughing and muscle tension; , on laughing and breathing; , on humour and fear, , on laughing and immunoglobulin A; , on laughing and pain).
In addition to the aforementioned primary effects, side effects can also occur. For example, the offer of a clinic clown in a hospital has the effect of creating publicity for the relevant institution. For the parents of paediatric patients and the hospital staff, the clown’s visits likewise provide distraction, stress relief and support. However, if a clown does not comply with the rules of a hospital or crosses the personal boundaries of a patient, there may be negative side effects. These include, for example, wasting money, disruption of workflows, annoyance and irritation among hospital staff and parents as well as helplessness, overtaxing and discontent among patients.
A search in the relevant abstract databases Embase, Medline and PsycINFO revealed a multitude of comments and case reports in predominantly low ranked journals. However, there exist several sample studies fulfilling more rigorous scientific criteria. These can be divided thematically into two groups, namely, controlled trials and evaluations of effectiveness under routine conditions. Systematic reviews or meta analyses do not exist to date.
Currently, there are a total of nine randomized controlled trials on the effect of hospital clowning during specific medical interventions. Five of these investigations deal with the presence of hospital clowns before, during, and/or after surgery or anesthesia induction and the possible reduction of anxiety [16–20]. One study analyzes the effect of clown intervention during botulinum toxin injections . Three trials [22–24] investigated a possible long-term effect (up to one day later) in the context of an in-patient hospital stay. Overall, the fear-and stress-reducing effect of hospital clowning could be detected in most studies, but not in all. In particular, a long-term effect beyond the actual duration of the clown visit has not been identified conclusively.
With regard to the attitudes and subjective assessments of the impact by the patients, parents and hospital staff that are of interest in the context of the present study, four independent studies have been published up to now:
Loidl-Keil et al.  evaluated the performances of hospital clowns in three different hospitals in Upper Austria. They surveyed n = 37 patients (3–20 years old, M = 11 year) and n = 98 nurses using a questionnaire on the acceptance and subjective experience of efficacy of the clown visits. The results of the evaluation were very positive overall. The clear majority of the children enjoyed the clown performances, wanted more frequent clown visits and preferred these to other entertainment activities on the ward. Only a small number of respondents reported feeling unwell or ill at ease or disturbed. The nursing staff gave comparable assessments.
Battrick et al.  evaluated the clown visits in an English hospital using a questionnaire from the point of view of n = 49 children, 43 parents, 93 hospital staff members and 17 physicians. The results showed a very positive reception by all groups. The vast majority (82%) of the children enjoyed the clown performances. Only 3 (6%) stated that they didn’t like the clowns. Almost all of the parents and hospital staff claimed that the presence of a clown doctor had a positive influence on sick children and their families. The physicians made comparable statements.
Glasper et al. [27, 28] studied the topic in three different study modules at an English children’s hospital. The result of two focus groups with n = 5 and 7 clowns showed that hospital clowns are well trained and take their profession very seriously. They believe they can improve the children’s care and perceive themselves as valued members of the hospital team. However, problems with scheduling appointments and prejudices of hospital staff were also mentioned. The survey of various groups of people (n = 17 physicians, 93 nursing staff, 43 parents and 49 children) confirmed the assessments of the focus group. Nearly all of the respondents valued the work of the clowns and believed that the performances would have a positive influence on the health of the patients. However, a few of the physicians stated that they personally did not like hospital clowns. In the third study module, n = 20 patients between the ages of 4 and 11 were asked to show in drawings and stories how they felt about a hospital stay before and after a clown visit. Before the clown visit, mostly negative comments (28 of 35) such as “sad”, “nervous” or “worried” were made, but after the clown visit, a significantly more positive perception appeared (57 positive and 3 negative comments).
Koller and Gryski  surveyed n = 143 staff members and 51 parents regarding the clown visits in a paediatric clinic in Toronto. The vast majority (85%) of the staff had no concerns with respect to the clown visits. Just under half stated that they experienced the clowns as a support for their own work and almost all of them evaluated the clown program as beneficial to the hospital. The parents expressed equally positive opinions: more than three quarters reported that their children and they themselves enjoyed the clown visits and almost all parents considered their children to be happier after the performances than before (94%).
Previous results regarding efficacy under routine conditions show that clown doctors do valuable work and are appreciated by patients as well as parents and hospital staff. However, up to now there have been almost no such systematic, empirical, scientific studies in Germany on the use, effect and side effects of hospital clowning for hospitalised paediatric patients under routine conditions comprising more than one hospital. The present report describes an initial evaluation of the actual state of care provision in this field.
The initial questions of the present study were:
What is the care provision situation with regard to hospital clowning in Germany?
How do hospital clowns, parents and ward staff rate the intervention?