March 14^th is a special day called Pi Day due to the fact that it is depicted as 3. 14  (the first three digits of circumference ratio) and in coincidence, it is also the anniversary of Albert Einstein's birth. This day has been endowed with a new connotation to the releasing of Productivity Index (PI) on March 14^th, 2019 by Shanghai Information Center for Life Sciences (Life & Health Technology Think Tank), Shanghai Institute of Nutrition and Health of Chinese Academy of Sciences (CAS).    

Productivity Index, also called π Index, is composed of a series of metrics of research productivity in life sciences and basic medicine. As the first research evaluation index developed in China, π index was firstly released in 2016.   

Based on the analysis of scientific articles and reviews published in 122 selected science journals in 2018, the 2019 Annual π Index Report include four parts: top 10 countries ranked by published paper numbers, top 500 institutions ranked by π factor, institutions’ distribution respectively in USA, England, China, Germany, France, and top 20 CAS institutions ranked by π factor. (http://bm.pi-index.com/indexen.jsp)  

As revealed in the report, among the top 10 countries ranked by published paper numbers, all the other nine countries published less paper in 2018 than that in 2017 except China. USA published the largest number of papers (22,354) and China rose from No.4 (5,055) to No.3 (5,136) with a rising ratio of 1.60%.     

Among top 500 institutions ranked by the π factor, Harvard University (266.36) hold the first place, followed by National Institute for Health and Medical Research (INSERM) (104.05) and National Institutes of Health (NIH) (103.98). CAS (80.07) still ranked No.8 with 44 institutions reaching in top 500. In addition, top three institutions with highest π quotient (π value divided by paper numbers) were Broad Institute (9.22), Memorial Sloan Kettering Cancer Center (MSKCC) (8.99) and University of Toronto (8.71), which first reached the top three. 

The institutions with the highest π factor respectively in USA, England, Germany, France, China were Harvard University (266.36), Oxford University (70.97), Max Planck Society (70.33), National Institute for Health and Medical Research (INSERM) (104.45), and Peking University (27.05). Whereas Broad Institute (9.22), Institute of Cancer Research (9.08), Max Planck Society (6.78), Institute Gustave-Roussy (7.24), Institute of Biophysics^[1] of CAS (9.10) hold the highest π quotient in each country.

Among the top 20 CAS institutions ranked by the π factor, the first seven also listed in the global top 500: Institute of Biophysics (11.06), Institute of Genetics and Developmental Biology (8.40), Institute of Biochemistry and Cell Biology (7.94), Institute of Plant Physiology and Ecology (7.42), Institute of Zoology (4.88), Institute of Neuroscience (4.69), and Kunming Institute of Zoology (3.17).  

Since its first release in 2016, the annual π Index has attracted great interests from many institutions and scientists. By providing valuable reference and guidance for the governmental officers and institutional leaders, π index will not only help them evaluate the academic performance of the institutions and researchers but also facilitate the funding policy making in supporting the development of life sciences and basic medicine at the national and institutional levels.