Pharmaceutical company spending on research and development and promotion in Canada, 2013-2016: a cohort analysis.

Depending on the method used to determine promotion spending, industry-wide the ratio of R&D spending to promotion ranges from 1.45 to 2.18 (sales representatives and journal advertising only) or from 0.88 to 1.32 (total promotion spending estimated based 2003-2005 data.) For the individual companies promoting one or more of the 50 most promoted drugs, 2.11 to 2.32 times more is spent on R&D compared to promotion. However these results should be interpreted cautiously because of data limitations.