Verily, Alphabet Inc's life sciences business, said it was launching a four–year study with about 10,000 participants to understand how people transition from being healthy to becoming sick, and to identify additional risk factors for diseases.

Verily is partnering with Duke University and Stanford Medicine in the United States to enroll participants from varying backgrounds at sites in California and North Carolina within the next few months.

The study is the first initiative of Project Baseline, a broader effort to develop a reference, or a "baseline", for what "health" refers to.

The study will collect data, as well as biological samples such as blood and saliva.

The sites will gather data from participants through repeat clinical visits, a wristwatch that monitors heart rate and activity levels, as well as participation in surveys and polls.

"The Project Baseline study has the opportunity to significantly influence our current body of knowledge by better understanding the indicators of wellness," Nancy Brown, chief executive officer of the American Heart Association, said in a statement. "The outcome of this study could inspire a new generation of tools that are geared towards disease prevention versus just diagnosis and treatment," she added.

Beyond this initial study, the project will also test and develop new tools and technologies to access and organize health information.

In September, pharmaceutical company Sanofi SA and Verily unveiled a $500 million investment in a joint venture which combined devices with services to improve diabetes care, an example of growing ties between the pharmaceutical and technology sectors.

Verily also has several other medical projects in the works, including the development of a smart contact lens in partnership with Swiss drugmaker Novartis AG that has an embedded glucose sensor to help monitor diabetes.

(Reporting by Anya George Tharakan in Bengaluru; Editing by Shounak Dasgupta)