If you're looking for great growth opportunities to invest in, look no further than the healthcare sector. Healthcare stocks have been big winners in recent years, and the future looks even brighter.

We asked three Fool.com contributors to pick their top healthcare stocks to buy right now. They chose DaVita (DVA -0.04%)PRA Health Sciences (PRAH), and Teladoc Health (TDOC -0.53%). Here's why these three stocks look like winners.

Man with a stethoscope around his neck pointing to a cloud icon next to healthcare icons

Image source: Getty Images.

This long-term patient trend is your friend

Sean Williams (DaVita): Sometimes the best healthcare stocks to buy are the ones that make you do the least amount of thinking. That's why Warren Buffett holding DaVita is a worth a much closer look.

DaVita is one of the largest providers of outpatient dialysis services in the United States, with 2,625 centers servicing 201,000 patients. Although estimates vary, the consensus among Wall Street analysts is that it controls about 35% of the outpatient dialysis market. Additionally, DaVita runs 251 outpatient dialysis centers in 10 countries outside the U.S. 

DaVita's size presents both a promise and a peril. The company comes under scrutiny on occasion for reimbursements from Medicare in the U.S., but at the same time it should benefit from a numbers game that unequivocally favors it over the long run. More specifically, the U.S. Census Bureau's 2017 National Population Projections suggest that one in every five residents will be of retirement age by 2030. Retirees are far likelier to require dialysis than younger folks, priming DaVita to succeed based on the sheer volume of patients.

In addition, the company's 201,000 patients as of Sept. 30, 2018, will be a drop in the bucket compared to the number of global dialysis patients the company should be treating by 2030. In the U.S., this should provide DaVita with more leverage when negotiating on reimbursements with private insurance companies and possibly even the federal government. 

While some folks might be turned off by DaVita's profit slump in 2018, I primarily attribute this to a one-time gain in 2017 that wasn't recognized in 2018. That aside, revenue growth should still be in the mid-to-upper single digits when all is said and done for the full year. With a genuine opportunity to more than double its earnings per share between 2018 and 2021, DaVita looks ripe for the picking. 

Check out the latest DaVita earnings call transcript.

Fast growth, value price

Brian Feroldi (PRA Health Sciences): It isn't easy to bring a new drug through the regulatory approval process. It can often take multiple years and cost tens of millions of dollars in research and development to even have a chance at winning a thumbs-up. The process is extremely challenging under the best of circumstances.

Given the long odds of success and huge costs, lots of pharmaceutical and biotech companies choose to partner with clinical research organizations (CRO) that specialize in this kind of work. CROs often have decades of experience under their belt and employ hundreds of experienced researchers. Hiring a CRO to do the grunt work can be an easy way to maximize their chance of success. 

PRA Health Sciences is one of the biggest CROs on the market. The company counts numerous pharmaceutical and biotech companies as customers and it has a built a reputation as being a great partner. That fact allows it to consistently win more than its fair share of new business.

An attractive feature of CRO companies is that they build up large backlogs of projects. That fact gives investors a lot of visibility into what the company's financial statements will look like in the near future. PRA Health Sciences' current backlog of projects totals $4.1 billion. That's a lot of pent-up demand, so investors should have confidence when its management team issues guidance. 

PRA has done a great job in recent years of turning its book of business into fast profit growth. Earnings per share have grown at a 31% annualized rate over the past five years. That fast growth rate is a big reason why shares are up more than 400% since the company's initial public offering (IPO) in 2014. 

Market watchers presently believe that PRA is still in growth mode. Current estimates call for the profits to grow in excess of 18% annualized over the next five years. That's quite fast for a winning business that is only trading for 20 times next year's earnings estimates. 

Check out the latest PRA Health Sciences earnings call transcript.

Good news for this leading telehealth stock

Keith Speights (Teladoc Health): First, the bad news: Teladoc Health isn't profitable. The telehealth services provider's stock is down nearly 30% from its highs in September 2018. And Teladoc's share price still looks expensive with a price-to-sales (P/S) ratio of 11.4. So why would I claim that Teladoc Health is a top healthcare stock to buy right now? Because the good news outweighs the bad news.

Although Teladoc isn't profitable yet, that's primarily because the company is pouring money into expansion. Revenue, on the other hand, continues to soar, with 62% year-over-year growth in the third quarter of 2018. Over the last five years, the company has increased its revenue by a compound annual growth rate of 75%. This level of growth makes Teladoc's current P/S multiple much less concerning.

Teladoc's customer base includes around 40% of the Fortune 500. The company has partnered with over 35 major health plans and more than 290 hospitals and health systems. Teladoc Health ranks as the largest telehealth services provider in the world, with the most extensive global reach and the widest offering of services.

But the market for telehealth has tremendous room to grow. Aging demographic trends are causing greater demand for healthcare services, prompting payers across the world to explore opportunities to control costs. Teladoc Health's telehealth services give payers a relatively easy way to control healthcare costs. 

Providing increased convenience for patients and cost savings for payers should be a winning formula for Teladoc Health for a long time to come. The good news is only beginning for this high-growth healthcare stock.

Check out the latest Teladoc Health earnings call transcript.