Quality and completeness of utilisation data on biological agents across European countries: tumour necrosis factor alpha inhibitors as a case study.

Purpose: For optimal decision making on access to and regulations around biologicals availability of national utilisation data is a prerequisite. This study characterises the main categories of critical issues in collecting available national utilisation data on tumour necrosis factor alpha (TNFalpha) inhibitors in different European countries.

Methods: Data were collected on characteristics of the nature of TNFalpha usage data and on usage of TNFalpha itself (2003-2007). Utilisation rates were expressed as defined daily doses (DDDs)/1000 inhabitants/day. Data from Denmark, Finland, Ireland, the Netherlands, Norway and Portugal were included.

Results: Characteristics of TNFalpha (usage settings and ways of distribution to patients) and databases (type of data collected, public availability and data sources) influenced the way data were collected and determined the type of research and policy questions that can validly be addressed. The prevailing differences in the structure of national databases are prohibitive for critical aspects of medicines utilisation studies. An increase in TNFalpha usage over time was observed in all countries and varied widely from 0.32 (Portugal) to 1.89 (Norway) DDDs/1000 inhabitants/day (2007).

Conclusions: In the European countries studied data on national TNFalpha usage is not easily, if at all accessible. Intercountry collaboration and sharing of technical resources will facilitate harmonisation of data collection allowing independent, population based, health and outcomes research.