WASHINGTON, DC-Another day, another mammoth-sized health-careportfolio acquisition. This week Griffin-AmericanHealthcare REIT II acquired 13-buildings known as the Pacific Northwest Senior CarePortfolio, plus an additional seven medical officebuildings for $103 million. It follows by roughlyseven days Health Care REIT’s announcement that itinked a definitive agreement to acquire Sunrise Senior Living for $1.9 billion.

The Sunrise Senior deal was the fourth M&A deal since 2010involving a publicly traded US health-care REIT, according toSNL Financial analysis. Ventaswas a chief player in this respect, acquiring CogdellSpencer and Nationwide Health Propertiesin 2012 and 2011, respectively, for a total of more than $8billion. Prior to those deals, Tiptree FinancialPartners acquired Care InvestmentTrust in the second half of 2010, for $264 million.

Demographics are a driver behind the deals, to be sure. Considerthe case of California, the highest-populated state in the Union,which is projected to see its population aged 70 and over grow bythe largest amount over the next five years, SNL says. US equityREITs account for 272 health care properties in the state.