The objective of this research was to compare trends in publications of network meta-analyses (NMAs) in cardiovascular diseases (CVDs) in Asia-Pacific (APAC; China, Japan, Singapore, South Korea, Thailand) and Europe (United Kingdom [UK], Germany, France, Spain, Italy), with a focus on volume, collaborations and methods.

Freely available NMAs assessing pharmacological or surgical interventions for CVD in terms of mortality or major adverse cardiovascular events, published in 2012 or later, by authors affiliated with institutions in the target countries were identified via MEDLINE and Embase. CVDs were grouped using the International Classification of Diseases, Tenth Edition (ICD-10).

Across the 193 publications identified, heart diseases such as atrial fibrillation, aortic stenosis and heart failure (ICD-10 I30-I52) were the most common indications reported (38%). The majority of publications involved authors in APAC countries (63%) and 40% from Europe. Cumulative numbers of publications from APAC surpassed those from Europe from 2018 onwards. Authors were largely affiliated with institutions in China (50%), the UK (20%) and Italy (20%). One hundred and forty-five publications were by authors affiliated with institutions in a single country; 91 percent of publications from APAC and 44 percent from Europe, indicating different patterns of collaboration within these regions. In terms of reporting methodologies, 39 percent of included publications did not specify whether a frequentist or Bayesian framework was used (43% in APAC, 34% in Europe). Among those that reported, the Bayesian framework was more commonly used.

Whilst there is a growing trend in NMA publication counts generally, the rate of increase in APAC was higher than Europe, particularly in the years following adoption of health technology assessment (HTA) procedures in APAC. The volume of publications not reporting the framework used was substantial, despite requirements for this in reporting guidelines e.g., PRISMA. Where reported, the Bayesian framework may have been favored due to its advocacy by some health technology assessment bodies.