BACKGROUND: Collecting patients' data in observational longitudinal studies is often a concern in terms of data accuracy and patient follow up. Depending of the study design, the physicians’ assessment might be not sufficient and/or non-feasible. Direct to patient contact (DtPC) process is commonly used to maximize the long-term follow up and ensure continuity and quality in data collection. OBJECTIVES: To demonstrate the benefit of DtPC, through example of multinational study. Challenges were to implement feasible and robust methods to collect and confirm Events of Interest for the study (EoI) in ‘real-life’ settings, fitting health care standards, regulatory and cultural requirements of countries involved.   METHODS: Longitudinal, international, observational study. Enrolling physicians were not primary patient’s Health Care Providers; consequently, patients had to be the main contact to capture the EoI. Patients had to complete and sign a Contact Order Form that allowed trained interviewers performing follow-up calls at regular time points during the follow up period. Baseline clinical and demographic data were collected by enrolling physicians. Then, the medical confirmation of EoI detected through telephone interviews was ensured by the involvement of the concerned EoI’s treating physician.   RESULTS: On average 85% successful interviews were performed, 2% patients withdrawn their consent, 3% patients were lost to follow up. On average, 80% of the EoI’s treating physicians accepted the process for medical confirmation and data collection of the EoI, despite strong variations depending on the country. CONCLUSIONS: The results of this study are in accordance with our previous experiences and confirms the benefits of using DtPC in international observational and longitudinal studies. This process enabled a harmonised and centralised method to obtain real life data overview for all patients included, whatever their country, a high level of patient adherence and a low rate of patient withdrawal, despite the large number of countries involved.