Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Team Health Holdings Inc. (NYSE:TMH) shares climbed by more than 10% at mid-day after reporting better-than-expected fourth quarter earnings results and issuing 2015 guidance that was above analyst estimates.

Source: Team Health Holdings

So what: Team Health Holdings, which provides physician staffing services to hospitals, reported that fourth quarter and full year sales reached $790.7 million, up 27.2% year-over-year, and $2.82 billion, up 18.3% year-over-year, respectively.

The company also posted solid bottom-line growth. Adjusted earnings per share, or EPS, improved by 21.7% to $0.56 in the fourth quarter and increased by 25.7% to $2.30 for the full year.

The company's top and bottom line growth stemmed from its ongoing acquisition strategy and solid contract pricing, but rising enrollment in Medicaid programs, which drives health care utilization and benefits the company's payer mix, also contributed. Overall, newly acquired physician groups accounted for 18.4% of the company's fourth quarter sales growth and 11.3% of the company's full year sales growth.

Team Health expects to acquire additional physician groups in the coming year, and that, along with rising demand tied to an increasingly insured population, has the company guiding investors to expect revenue of between $3.33 billion and $3.38 billion in 2015, which would be 18% to 20% higher than 2014. Overall, the company estimates that the total addressable market for emergency, anesthesia, and hospitalist personnel is worth $26 billion.

Source: Team Health Holdings

Now what:  Hospitals continue to embrace outsourcing models in a bid to improve margin and that offers ongoing tailwinds for Team Health. Since the company provides staffing services for emergency rooms, anesthesia, pediatric, and other departments to 980 hospitals, and its client retention rate is 98%, investors could find that Team Health Holdings is an intriguing way to play an aging and increasingly insured America.