Dissemination bias occurs when only some results
emerging from clinical research reach their intended audience in the
knowledge translation process. Given that coverage decisions
increasingly rely on evidence, it is important to explore the types of
evidence considered. This paper aimed to examine the evidence base
used by regulatory institutions involved in pricing and reimbursement
of pharmaceuticals in a broad range of European countries, as well as
their awareness of and approach towards dissemination bias.
A mixed methods approach was adopted.
Regulatory documents and published literature were identified in
systematic searches and relevant documents were analysed. An online
survey was carried out to verify and expand insights.
Forty-two relevant regulatory documents and 10
publications were included. The survey had a 35% response rate,
yielding valid responses for 13 countries. A fragmented impression was
obtained for most countries indicating a general lack of transparency
regarding both processes of decision-making and approaches towards
unpublished information. Dissemination bias was rarely consistently
considered. Practices for the identification and inclusion of all
available evidence varied considerably, as did the influence of
missing evidence on decision-making. Differences were often
attributable to the regulatory context and/or institutional
Best practice is difficult to generalize given
the identified variations. Individual exemplary practices support the
necessity for institutional exchange at international level. Increased
institutional commitment to transparency of methods and processes
should be advocated.