Investing in trends that are unlikely to reverse is key to being a successful investor.

A more populous and aging global population is almost a guarantee that quality healthcare stocks will do well over the long haul. That's because healthcare products and services are essential to extended life expectancies, which also builds in pricing power for such stocks.

Here are three healthcare stocks that have proven to be reliable dividend growers, and each looks like a solid buy for this month.

A team of healthcare professionals work in the operating room.

Image source: Getty Images.

1. Medtronic

With a $145 billion market capitalization and operations in 150 countries, Medtronic (MDT 0.72%) is the largest pure-play medical devices stock in the world. 

The company's 49,000-plus patents and 300-plus ongoing clinical trials across a variety of treatment areas like diabetes, cardiovascular disease, and neuroscience position it to be the biggest beneficiary of a promising industry forecast. Rising rates of chronic disease and an aging population are expected to help the global medical devices industry compound at 5.5% annually from $532.6 billion in 2021 to $734.4 billion in 2027. 

This explains why analysts anticipate that Medtronic will be able to deliver 12.2% annual adjusted diluted earnings per share (EPS) growth through the next five years. 

And with a dividend payout ratio set to be 44.5% for its fiscal year ending this month, the stock should hand out high-single-digit annual dividend increases for the foreseeable future. Given Medtronic's market-beating 2.4% dividend yield, this is a nice mix of starting yield and growth potential. 

At the current $105 share price, Medtronic trades at a forward price-to-earnings ratio of just 18. This is an enticing valuation for a blue-chip stock with strong growth prospects, which is what makes Medtronic a solid buy for long-term investors.

2. AbbVie

The next stock to consider buying in May is AbbVie (ABBV 0.76%). AbbVie's $270 billion market cap makes it the fourth-largest pharma stock in the world. 

Unsurprisingly, the mega-cap stock features one of the most impressive drug portfolios in the world. AbbVie's portfolio contained 13 blockbuster drugs in 2021, including the top-selling drug in the world, Humira. 

It's easy for such a successful company to rest on its laurels. But that doesn't appear to be what AbbVie has done over the past several years since it has 60 compounds in different phases of clinical development. Analysts predict the company's stacked drug portfolio/pipeline and increasing demand for pharmaceuticals will lead to a 2% annual earnings growth over the next five years.

Better yet, AbbVie is a Dividend King that offers a market-crushing 3.8% dividend yield. What's more, the stock's projected 40.2% payout ratio for 2022 leaves it room to grow its dividend ahead of earnings over the medium term. That's why I am expecting mid-to-upper single-digit annual dividend growth over the next several years, which is a healthy combo of income and growth.

Investors can snatch up AbbVie's stock at $150 a share, which works out to a reasonable forward price-to-earnings (P/E) ratio of just 12.2. 

3. Humana

The third stock to think about purchasing this month is Humana (HUM -1.41%). The stock's $57 billion market cap makes it the fifth-largest health insurer in the world.   

Healthcare costs are steadily rising, and more people in the U.S. are turning to health insurers to assume risks on their behalf. Along with Humana's status as a leading health insurer, this is why analysts are anticipating 14% annual earnings growth for the next five years.

And given that Humana's dividend payout ratio will be less than 13% in 2022, the stock has plenty of room to grow its payout in the years ahead. This makes up for Humana's low starting yield of 0.7%. 

Best of all, Humana's stock trades at a forward P/E ratio of 15.6. This is a more-than-fair valuation for a stock with low-teens annual earnings growth in its future, which makes Humana an interesting buy for long-term investors.