The purpose of Biobadaderm is a to study the safety of systemic therapy in psoriasis.

The Spanish Registry for Adverse Events of Biological Therapies in Dermatology (BIOBADADERM) was launched in October 2008, as a pharmacovigilance effort for psoriatic patients. The registry is managed by the Foundation of the Spanish Academy of Dermatology and Venereology (AEDV). BIOBADADERM has been promoted by the AEDV, in collaboration with the Spanish Agency for Medicines and Health Products (AEMPS) and the Research Unit of the Spanish Foundation of Rheumatology (FER) and the Research Unit of the Fundacion AEDV. BIOBADADERM is part of PSONET, a European network for sharing data from records of patients treated with biologics.

BIOBADADERM is a prospective cohort of patients receiving biologic drugs that can be compared with another cohort of patients receiving other systemic treatments. One of the cohorts is made up of all consecutive psoriasis patients who begin any biological therapy (including infliximab (INF), etanercept (ET), efalizumab (EFA), adalimumab (ADA), rituximab (RTX) and ustekinumab (UTK)) in each centre. The control cohort consists of psoriasis patients who begin, for the first time, a nonbiologic systemic treatment (methotrexate, cyclosporine or acitretin).

The objectives of BIOBADADERM are:

• Identify adverse events (AEs) occurring during the relevant treatment with biologic therapies, and estimate their frequency;
• Identify unexpected AEs, particularly those that may occur after long periods of exposure;
• Identify relevant AEs that arise after discontinuation of treatment;
• Estimate the relative risk of developing AEs with biologic therapies in patients with psoriasis compared to psoriatic patients exposed to other systemic (non-biological); and
• Identify risk factors for AEs in patients with these treatments.

Data were initially collected retrospectively in hospitals with a list of all patients who had received biologic drugs between 1 January 2005 and 30 October 2008 and check-ups with a frequency of at least every 6 months. Since 2008, data have been captured prospectively.

The database includes demographic, diagnostic and comorbidity data, the treatments performed, the duration of these treatments and the adverse effects that arise (coded using MedDRA). In its first year, 632 patients from 12 centers participated with BIOBADADERM. In October 2012 the registry had data from 1,793 patients, which includes 946 patients on biologic treatments and 847 patients on non-biologic systemic treatments.

Data for each patient have been reversibly anonymized and entered into a database. Data are entered over the Internet (http://biobadaser.ser.es/biobadaderm/). The data are stored in the Research Department of the Spanish Rheumatology Foundation.

The included data are continually revised online by a study monitor to verify consistency, comprehensiveness, and absence of anomalies. A follow-up visit is made every year during which a sample of the the data in the database are compared with those in the clinical records.

Sample size was calculated to give, after 5 years, 80% power and using alfa level= 0.05, to detect a rate ratio of 2 in events with 4.1 cases per 1000 person-years, or a rate ratio of 5 in events with 0.5 cases per 1000 person-years. Further calculations are available in the study protocol (https://biobadaser.ser.es/biobadaderm/index.html).

Default value in each variable is "missing". Plans for missing data in analysis depend on the aim of analysis but with a preference for the most conservative ( in terms of patient safety) analysis.

Analysis consists of description of rates, rate ratios and adjusted rate ratios (adjusted for possible confounders, age always included).

Inclusion Criteria:

• For biologics group: all consecutive psoriasis patients who begin any biological therapy
• For classic systemic group: the next psoriasis patients who begin, for the first time, a nonbiologic systemic treatment (after including a patient in the biologics group)

Exclusion Criteria:

• Intention of moving to a different geographic area in the next three months

Psoriasis patients requiring systemic therapy.