Research protocol extract

August 2019, Version 3




The purpose of the Hidradenitis suppurativa registry (HSR) is to evaluate the long-term course, safety clinical outcomes and health related quality of life of patients with Hidradenitis suppurativa (HS). Patient will be enrolled in the HSR with a confirmed HS diagnosis only and treated in the participating centers. Patients will remain in the HSR for 3 years, regardless of subsequent therapy





Hidradenitis suppurativa (HS) is a multifactorial, chronic, recurrent, debilitating, inflammatory skin disease, which can lead to severe scarring and disability and is associated with reduced quality of life, depression, working disability, pain, social stigmatization and cardiovascular risk factors. It is an under-recognized and under-studied skin disease. Currently there are only few studies for the management of HS (systemic treatment and surgery) and most often the rationale for the use of most systemic treatments and surgery is based on low level of evidence. Many critical clinical and epidemiological questions remain unanswered. There is hardly any evidence on the benefit/risk ratio of treatments, both short- and long-term. Risk factors and natural course of the disease are largely under-studied. There is great variation in treatment offered on a European level. Recent data indicate that the disease is strongly associated with working disability. All the above-mentioned evidence indicates that it is crucial to obtain valid answers in time to many clinical and epidemiological questions regarding HS. The development of a registry of HS patients is an important and scientifically valid method to study and answer many clinical and epidemiological hypotheses. The registry will provide real life data, including post marketing surveillance. It will facilitate development of predictive models, will lead to multiple benefits both on clinical and research level. The registry will enhance a European collaboration and benefit the management of HS patients.





The objective of the current project is the development the registry for HS patients in Switzerland. The register aims to recruit and enroll all patients with HS that are diagnosed and treated in the participating centers. The register will undertake the responsibility to deliver consensus reports, expert recommendations and annual updates from the register. A core data set of important variables, both physician and patient rated, will be collected in specific time points.



Tasks, milestones and timelines


Planning and development of the web-based registry was established within the last two years.
Registry start is planned for April 2019 (first patient in).



Methods | Definition of population




The population of patients is constituted of all patients with a diagnosis of HS in Switzerland. The actual patients of the participating study centers define the accessible population. The population is sparsely confined by following in- and exclusion criteria.


Inclusion criteria


  • Patients with diagnosis of HS confirmed by a dermatologist,
  • Age >18,
  • Being administered a specific systemic drug for the first time
  • Sufficient language skills (German, French, Italian and English) for the informed consent to participate
  • Informed consent to participate


Exclusion criteria


  • Lack of informed consent




Observation starts with the initiation of a systemic treatment applied for the first time. As described previously, the treatment is performed according to the current drug regulation and according to the European and national guideline on HS treatment. The registry is based on observational data only, therefore there are no limitations to treatment.




Recruitment of patients will take place in dermatologic practices and clinics. Dermatological practices and hospital outpatient departments in Switzerland (possible collaborations with Germany /Austria planned in the future) with adequate expertise in treatment of HS are the population of providers of care. Centers are willing to enter the documentation electronically.




The analyses will be made descriptively and reported as sequential time-series data and by subgroup tabulations, from which reports on safety and other outcomes will be generated at regular intervals.
Analyses will take into account switching from the group with systemic treatment to a biologic agent (and vice versa) as well as switching from one product of a treatment group to another.

During the course of the registry analyses will also be made based on a nested case-control design, i.e. “cases” with a certain outcome of interest will be compared with regard to differences in exposures variables (treatments) to matched “controls” in which this outcome hasn’t occurred.


Encrypted data might be shared with other research centers (no plan or contract regarding a specific research center currently exists). Other European countries are working on a similar registry thus a cooperation seems possible, but has not been either planned nor contracted yet.


If any participating center wants to analyze data in order to publish a manuscript, another ethical proposal will be performed.


Authors: Dr. Florian Anzengruber, Vahid Djamei