After beating the market in 2011, healthcare stocks may struggle for a repeat performance this year as cash-strapped Americans keep putting off use of medical services and investors seek out faster growth stocks as the economy improves. Thus far, GSPA is up about 4 percent compared to a 7 percent increase for the S&P 500 index. Last year, the healthcare index rose 10 percent compared with little change for the broader market, as investors sought out shares of pharmaceutical companies and health insurers as a defensive play against the market’s volatility. A rebounding U.S. economy could lead patients to resume doctor visits and elective procedures they had been putting off, which would benefit medical device makers, drug companies and healthcare providers such as hospitals. But that trend may take a while to materialize.