Coffee giant Starbucks (SBUX 0.51%) is scheduled to report fiscal first-quarter results on Jan. 24. Following a strong 2018 in which the stock crushed the market, expectations are high. In its fourth quarter, the company's momentum was evident across multiple key metrics, including comparable-store sales, revenue, earnings per share, and active rewards members.

When Starbucks reports its fiscal first-quarter results, investors will get to see if the company's recent reacceleration will prove to be short-lived or rather a preview of strong results in fiscal 2019. Can Starbucks impress investors for a second quarter in a row?

Here are three areas worth watching when the coffee company reports its first-quarter results next week.

A barista holding Starbucks' 2017 Holiday cup

Image source: Starbucks.

Revenue

On the surface, Starbucks' revenue growth in its fourth quarter of fiscal 2018 suggests there wasn't an acceleration in the coffee giant's business during the quarter. For both Q3 and Q4, consolidated revenue rose 11% year over year. But when the net impact of currency changes and activities to streamline operations are excluded, third-quarter revenue was up 7% year over year, and fourth-quarter revenue was up 9% -- two percentage points higher than Q3's growth.

Can Starbucks' maintain this accelerated growth rate in its first quarter of fiscal 2019?

Comparable-store sales

One of the most important metrics for Starbucks investors to watch is the company's comparable-store sales trends. Measuring sales trends at stores open at company-operated stores for 13 months or longer and excluding the effect of fluctuations in foreign currency exchange rates, comparable-store sales trends give investors insight into how the company's stores are performing.

This key metric accelerated significantly in fiscal Q4, highlighting promising momentum for the company. Comparable-store sales were up 3% globally, driven by 4% growth in U.S. comparable-store sales. This compares to just 1% growth in global comparable-store sales in Q3.

Fortunately, management expects this accelerated pace in comparable-sales growth to persist. The company guided for 3% to 4% growth in the key metric in fiscal 2019. Investors, therefore, should look for first-quarter comparable-sales growth to come in somewhere in this range.

Digital relationships

One way Starbucks has driven sales growth over the years is by engaging its customers through digital relationships. These efforts remain important to the company, with active rewards members increasing 15% year over year in Q4 -- the company's highest growth rate in seven quarters.

"These customers continue to drive nearly 40% of tender in the U.S. with Mobile Order and Pay representing 14% of transactions," said Starbucks Chief Operating Officer Rosalind Brewer in the company's fiscal fourth-quarter earnings call.

The company has also recently started forming digital relationships through customers that are not rewards members, growing this number from zero to 10 million in fiscal 2018. Four million of these digital relationships were added in Q4 alone. Investors should look to see how many new non-rewards digital relationships Starbucks can form in Q1.

Starbucks reports its fiscal first-quarter results after market close on Thursday, Jan. 24.