 SPRINGFIELD, Va.--BUSINESS WIRE--Spok, Inc., a wholly owned subsidiary of Spok Holdings, Inc. NASDAQ: SPOK and a global leader in healthcare communications, earned top honors for the fourth consecutive year in a survey of healthcare industry clients by Black Book Research on top-rated secure communications platforms. The honor means more this year than ever, and demonstrates our market leadership, as healthcare systems continue to battle COVID-19, said Vincent D. Kelly, president and chie 