From the 560 crowdfunding campaigns, in total, 180 did not meet one of the inclusion criteria. As a result, the final sample included 380 crowdfunding campaigns.
The health problem
In several crowdfunding campaigns we identified more than one condition, disease or disorder which prompted individuals to ask for donations. Individuals listed one to six conditions per crowdfunding campaign. In 18 campaigns, although the campaign was evidently health-related and the cost to be covered from the donations could be identified, the condition was not specified. In the majority (62.63%) of campaigns (238 out of 380), individuals listed one specific reason. In 25% of campaigns (95 out of 380), individuals specified two conditions. In 20 campaigns (5.26%) three conditions, in seven campaigns (1.84%) four conditions, and in one campaign five conditions were listed. As a maximum, individuals mentioned six different conditions (n = 1).
The most frequent conditions, diseases or disorders which motivated individuals to ask for donations are shown in Table 1; the last column of the table provides information about the cost to be covered. As shown in Table 1, the most frequent health problems include cancer, mental disorder, disability, accident, lipoedema, genetic disorders and rare diseases, elderly and dementia, sclerosis, and oral health.
Around one fourth of crowdfunding campaigns (101 out of 380; 26.58%) were related to cancer/tumour. Table 2 shows the cancer type by body location or system; this information could be extracted only for around half of the campaigns (51 out of 101); no details were provided in the remaining campaigns. Malignancies of the brain, breast, gastrointestinal tract and leukaemia were the leading cancer indications for crowdfunding. Most commonly individuals asked for donations for various therapies not financed by the health insurance fund (n = 42), including alternative therapies, scientifically poorly supported therapies and innovative therapies such as therapies with new substances, micro-immune therapy, Methadon-therapy, and stem cell infusion. Immunotherapy and rehabilitation after surgery were also requested several times. The second most common cost element individuals aimed at covering from the donations were living expenses (n = 26). Cancer is a chronic condition  which puts a significant financial burden on families due both to patient co-payment (medication, immune strengthener) and lost income.
The second most frequent health problem listed in around one-tenth of crowdfunding campaigns was mental disorder, typically depression (n = 34, 8.94%). Those suffering from mental disorder most frequently sought additional funding for animal-assisted therapies or living expenses. Funding for various therapies such as psychotherapy or infusion therapy was also often requested.
Disability was the third most frequent motive for crowdfunding; individuals with a wide array of disabilities and their families were in financial need (n = 26, 6.84%). The 26 disability-related campaigns shown in Table 1 can be explained by reasons other than genetic disorder and rare disease (n = 20), autism spectrum disorder (n = 8), paresis (n = 5), cerebral palsy (n = 2) and cases where animal-assisted therapy was requested (n = 26); these severe disabilities are listed separately and excluded from this category. In this category disability covered, for example, brain damage, severe asthma, severe epilepsy, cancer-related disability, and spinal cord or back injury. In the majority of the campaigns, individuals requested funding to facilitate their mobility (electric wheelchairs, wheelchair-accessible vehicles, handicapped-accessible homes).
Accident was ranked as the 4th most frequent cause for medical crowdfunding (n = 23, 6.05%); these campaigns were posted to provide relief from the severe consequences of a past accident. From the donations individuals aimed to cover a wide array of expenses, such as handicapped-accessible cars, living expenses and various therapies, for example, physiotherapy, rehabilitation, and Adeli-therapy.
The 5th most frequent medical condition mentioned was lipoedema (n = 22, 5.79%). Lipoedema is a disorder with symptoms of swelling and enlargement of the lower limbs; an abnormal amount of subcutaneous fat is deposited under the skin . Genetic and hormonal factors contribute to the risk of developing lipoedema . As of now no effective treatment for lipoedema exists; only symptoms can be alleviated. In crowdfunding campaigns individuals almost exclusively requested funding for surgery to remove fat tissues, arguing that the health insurance fund does not cover the cost of the desired intervention.
Genetic disorders and rare diseases were mentioned in 20 out of 380 campaigns (5.26%) and ranked in the top six. Down syndrome was listed in three campaigns, and Rett syndrome in two campaigns. Other genetic disorders and rare diseases were mentioned only once. These covered a wide array of conditions, such as Ehlers-Danlos Syndrome, Hodgkin’s Syndrome, Lesch-Nyhan Syndrome, and Li-Fraumeni Syndrome. Those suffering from genetic disorders and rare diseases requested funding for diverse activities. Various therapies, such as physiotherapy, therapy with animals, innovative and scientifically poorly supported therapies were high on the wish list, followed by living expenses, and medical aids to increase mobility.
The 7th most frequent medical condition mentioned in crowdfunding campaigns was dementia and elderly care (n = 19, 5.00%). Dementia and old age in general are associated with poorer health status and several symptoms; symptoms might be so severe that they interfere with daily life. Crowdfunding campaigns were initiated with diverse purposes, among others to support an existing elderly care institution and to cover living expenses.
Both sclerosis and oral health urged individuals to launch crowdfunding campaigns in 15 cases (3.95%). Lateral sclerosis (the death of neurons controlling voluntary muscles) and multiple sclerosis (damaged insulating covers of nerve cells in the brain and spinal cord) may develop into severe and disabling disease; patients’ muscles become uncoordinated and weak and they might lose their ability to walk [79, 80]. This lifelong condition puts a heavy burden on the patients and their families; individuals most frequently asked for financial support to cover their daily expenses. Funding was also frequently requested for research. Regarding oral health, donations were requested from the crowd for dental or orthodontal treatment not covered by health insurance. In several cases, although health insurance covered some previous treatments, the requested treatment was no longer covered.
Table 3 lists the 10-19th most frequent condition, disease or disorder which prompted individuals to ask for donations from the crowd. The table also provides information about the costs to be covered from donations. Table 4 shows those health problems for which individuals requested funding only in a few campaigns (five or less).