The US still dominates the clinical trials scene by a large margin - holding a 48.7 per cent share with 36, 281 sites - more than eight times the number of trial sites than second-place Germany.
The remaining three countries in the top five - France, Canada and Spain - are all in " traditional " regions and together host 66 per cent of all trial sites, the study found.
Italy, Japan, the UK, the Netherlands and Poland (with a 1.6 per cent market share -the only "emerging" region) comprise the remainder of the top ten, followed by Australia, Russia, Belgium, Czech Republic, Argentina, India, Brazil, Sweden, Mexico, Hungary, South Africa, Austria, China, Denmark and South Korea tailing the group with 0.6 per cent of the market.
Countries in emerging regions (Eastern Europe, Latin America, Asia, Middle East and Africa) are small players when analysed individually, each with less than 2 per cent global share, although collectively their presence is notable - as a group they actually host 17 per cent of actively recruiting sites, the data revealed.
Eastern Europe and Latin America generally currently host more sites than Asia, although India and China have " grown rapidly from an almost negligible base in just several years " and their high average relative annual growth rates, coupled with their very low density of trials and current levels of investment in clinical research infrastructure, suggest that they have potential to grow into " major players " in the future, the researchers wrote.
The researchers also said they believe that the factors that are driving the globalisation process will only continue, " resulting in the solidification of trends and increased geographic dispersion ".
The figures back this up - in terms of growth rates, 24 of the fastest growing 25 countries are from emerging regions.
These countries were initiating only 8 per cent of trials in 2002, whereas in 2006 this figure had risen to 20 per cent.
On the other hand, 19 of the 25 slowest growing top 50 countries are from traditional regions.
On a capacity level, traditional countries (namely the US, Canada and in several in Western Europe) again dominate, although according to the report, some of the emerging regions now have capacity approaching that of the traditional regions, particularly the Czech Republic, Hungary and Estonia.
Specialty-wise, the study found that although North American sites comprise 56 per cent of all trial sites, early-phase trials are disproportionately high in North America (62 per cent), whereas confirmatory trials are disproportionately high in Eastern Europe, Latin America and Asia.
Meanwhile, postmarketing trials are disproportionately high in Western Europe, and are less frequent in North America, Eastern Europe and Latin America.
The data emerged from a study initiated by researchers from the Massachusetts Institute of Technology (MIT), titled: " Trends in the globalization of clinical trials ," and published in the January 2008 issue of Nature Reviews Drug Discovery.
The study is believed to be the first of its kind: " We are unaware of any recent Medline-indexed publications quantifying the globalisation of biopharmaceutical clinical trials… based on publicly accessible data ", the researchers wrote.
The data was sourced from information posted on www.clinicaltrials.gov .