While most wealthy investors around the world expect to live to 100, they are also anxious about the implications longevity will have on their spending, investing and giving, according to a report released Thursday by UBS.

Among the biggest concerns high-net-worth individuals share universally is rising healthcare costs, although this issue nags U.S. investors most. About 69% of U.S. investors agree that health expenses are their biggest financial concerns related to longevity, compared to 52% globally, according to UBS Investor Watch, based on surveys of over 5,000 investors with at least US$1 million investable assets.

Out of the 10 countries/regions in which the survey is conducted, Germany-based investors (76%) are most optimistic about living to 100, while U.S. investors are the least optimistic. Although almost half (49%) of U.S. investors want to live to at least 100 years old, less than one-third (30%) believe they will, according to the report.

The majority of U.S. investors simply believe they are being realistic, with the current life expectancy being 80 on average. However, almost two-thirds (66%) of U.S. investors cite family history (they don’t have any direct relatives living to 100) and more than half (53%) doubt healthcare will be advanced enough to help them pass a century mark.

“The risk of being pessimistic about their longevity is under-planning,” says Michael Crook, chief investment officer of UBS Global Wealth Management. “Those investors don’t adequately take into account increased life expectancy.”

The wealthy “still worry about difficult choices they may face, such as spending a portion of their children's inheritance to pay for healthcare, or working longer to sustain their lifestyle over time,” said Paula Polito, Global Client Strategy Officer and Group Managing Director at UBS Global Wealth Management, in the report. “Already, we are starting to see longevity change long-practiced financial behaviors.”

In fact, three- quarters (75%) of U.S. investors plan on making financial changes and spending habits due to extended life spans, compared to 91% globally.

To adjust their wealth management strategy, U.S. investors prefer equities and real estate as long-term investments, while globally investors see cash as a good long-term holding.

In terms of legacy impact, 46% of U.S. investors plan to give more wealth away while they're still alive, compared to 62% globally, according to UBS.