Other components of ABC’s Shonda Rhimes-branded TGIT may be ailing, but leadoff hitter “Grey’s Anatomy” has never looked healthier.

In a good example of how younger viewers are discovering veteran shows on multiple platforms, the hospital drama has seen a ratings resurgence in its 12th season — driven largely by adult women under 35 who were probably in middle school or high school when the show bowed in 2005. In this category, heading into its final four episodes starting tonight, “Grey’s” ranks second among all broadcast shows, behind only Fox’s “Empire.”

Season-to-date, same-night television viewership in most categories for “Grey’s Anatomy” is down in the single-digits from last year, according to Nielsen — itself a positive sign at a time when many returning series are tracking 20% or more lower due in large part to an ever-growing volume of scripted series across the dial. But a look at 35-day multi-platform ratings through March provided by ABC Research/Videobiquity reveals those arrows turn from red to green when DVR playback, video-on-demand and online viewing are part of the mix.

Specifically among women 18-34, while the percentage of Americans watching “Grey’s Anatomy” on Thursday night is 9% lower than last year (2.87 vs. 3.15), it is tracking 11% better than last season in 35-day multi-platform ratings (7.94 to 8.84). Outside of “same-day” ratings, the show is up in every other measurable: DVR and VOD within three days (up 1%, 1.92 to 1.94), DVR playback in days 4 through 7 (up 12%, 0.40 to 0.45) and, in the biggest surge, VOD usage for days 4-35 and online viewing on Hulu and ABC.com within five weeks of a telecast (up 45%, 2.47 to 3.59).

“(The research) confirms a lot of what we’ve heard anecdotally, which is that there are a lot of younger viewers who have been catching up and jumping in,” said said Lisa Heimann, VP, ABC Multi-Platform Research. “They’re more likely to watch on digital platforms, but when you add everything together, there’s a pretty impressive number of women 18-34 that are still watching the show in its 12th season.”

Because “Grey’s Anatomy” premiered in March 2005, months before the start of Nielsen’s inclusion of DVR playback and before online offerings and iTunes made it easier for fans to watch on one’s own timetable, the drama provides researchers a great case study of how viewing habits have changed in a relatively short time period.

“It’s one of those shows still on the air that we can go back and say ‘remember when,’ ” says Heimann. “And the other thing for us is it allows us to put into perspective the fact that when you add up all that viewing of the people who watched the season premiere (last September), it’s bigger in totality than the total who watched it (the series premiere) live in March of 2005.”

Other “Grey’s Anatomy” findings by ABC Research that help explain the show’s overall growth in popularity include: 38% of viewers who streamed the show over last summer went on to watch the series on ABC in the fall; 57% of “Grey’s Anatomy” online viewers are adults 18-34, as opposed to just 20% of the linear TV audience; and viewing of the pilot episode alone has more than doubled over the past five years.

Many thought the show would have a hard time recovering from the death of Patrick Dempsey’s character Derek around this time a year ago, but the opposite seems to have occurred. And here’s where the increased opportunities to watch a show may be helping.

“With McDreamy (Derek) dying, I think there’s a lot of nostalgia,” Heimann said, “so the combination of new viewers watching online and maybe some lapsed viewers checking back in has made the show hot again.”