Apple Inc's healthcare technology is spreading quickly among major U.S. hospitals, showing early promise as a way for doctors to monitor patients remotely and lower costs. Fourteen of 23 top hospitals contacted by Reuters said they have rolled out a pilot program of Apple's HealthKit service - which acts as a repository for patient-generated health information like blood pressure, weight or heart rate - or are in talks to do so. The pilots aim to help physicians monitor patients with such chronic conditions as diabetes and hypertension. Apple rivals Google Inc and Samsung Electronics, which have released similar services, are only just starting to reach out to hospitals and other medical partners. Such systems hold the promise of allowing doctors to watch for early signs of trouble and intervene before a medical problem becomes acute. That could help hospitals avoid repeat admissions, for which they are penalized under new U.S. government guidelines, all at a relatively low cost. The U.S. healthcare market is $3 trillion, and researcher IDC Health Insights predicts that 70 percent of healthcare organizations worldwide will invest by 2018 in technology including apps, wearables, remote monitoring and virtual care.Those trying out Apple's service included at least eight of the 17 hospitals on one list ranking the best hospitals, the U.S. News & World Report's Honor Roll. Google and Samsung had started discussions with just a few of these hospitals.Apple's HealthKit works by gathering data from sources such as glucose measurement tools, food and exercise-tracking apps and Wi-fi connected scales. The company's Apple Watch, due for release in April, promises to add to the range of possible data.Apple has said that over 600 developers are integrating HealthKit into their health and fitness apps. Many of the hospitals told qthey were eager to try pilots of the Google Fit service, since Google's Android software powers most smartphones.