Unless you recently fell off the proverbial turnip truck (and avoided being injured by the subsequent fall), chances are you know there is a serious healthcare crisis in the United States. Firebrand filmmaker Michael Moore doesn't tell us much that we don't already know in Sicko, nor does he unearth any earth-shattering epiphanies. What Moore does do, and exceptionally well, is tear into the issue with the gusto of the zealous showman that he is.

Moore's approach incorporates at least one novel twist. Instead of centering on the 47 million Americans without health insurance, he spotlights the horror stories of folks who actually are insured but denied coverage by suspicious, penny-pinching insurance companies and HMOs. Some of the anecdotes are flat-out outrageous, like that of a woman who was knocked unconscious in a traffic accident but whose subsequent ambulance ride to the hospital was denied coverage because it hadn't been pre-approved. In another case, Blue Cross dropped coverage for a woman who was diagnosed with cancer because the company's investigators decided she hadn't divulged an earlier -- wait for it -- yeast infection.

Other tales are beyond absurd; they are heartbreaking. Anyone familiar with Moore's work (Fahrenheit 9/11, Bowling for Columbine) knows he is not one for subtlety. He is brazenly manipulative, right down to the treacly musical score, and his use of ironic humor is heavy-handed enough to make Larry the Cable Guy seem like Harold Pinter.

Even so, these stories are too wrenching to muck up. Medical bills account for more bankruptcies and cases of homelessness than any other single factor in the U.S. Some 18,000 Americans are expected to die this year alone as the result of not having health insurance. Moore is on the side of the angels here, and there is no denying that Sicko has moments of real power, passion and outrage.

Other facets of the healthcare industry take their lumps, too. Drug companies are skewered for their role in securing Medicare's budget-busting prescription-drug benefit. Moore follows the bread crumbs linking Congressional staffers to cushy jobs in the pharmaceutical industry, including the $2 million lobbyist gig that U.S. Rep. Billy Tauzin snatched shortly after he shepherded the Medicare bill through Congress (Moore accompanies this factoid to the strains of "I've Got a Golden Ticket" from Willy Wonka & the Chocolate Factory).

Moore certainly unleashes most of his scorn on Republicans such as Tauzin and George W. Bush, but he also takes the occasional shot at Democrats. He praises Hillary Clinton's ill-fated push for universal healthcare in the Nineties, but ultimately bashes her for surrendering to campaign contributions from the healthcare industry.

But Moore is an uneven filmmaker, and things get a bit wobbly when he stops illustrating the problem and purports to seek a solution. In a travelogue of sorts, Moore visits Canada, France and the United Kingdom to tout the glories of universal healthcare. He is only moderately successful. Moore effectively demystifies the bogeyman of "socialized medicine" -- a phrase long demonized by its opponents -- but he is mighty superficial and selective in what he shows. Talking to satisfied Canadians in a physician's waiting room is hardly conclusive stuff, nor does he prove that the French are not overtaxed just because he finds an affluent married couple in Paris. Admittedly, there are some amusing moments, such as Moore's ride-along with a French doctor who conducts house calls. In the end, however, whimsy and silliness undermine Moore's argument for socialized healthcare.

Moore figuratively falls off the boat as soon as he literally boards one. Rounding up a group of sick folks with illnesses related to their having volunteered at Ground Zero in the wake of 9/11, Moore sets course for the prison at Guantanamo Bay. The gimmick: To show that suspected terrorists incarcerated at Gitmo get better (and freer) health care than 9/11 volunteers. Moore is denied entry to Guantanamo, of course, and so he proceeds to Havana -- and a misguided glorification of Cuba's healthcare system. It's a ridiculous excursion. There is little doubt Castro's regime would use the occasion of an American film crew to put its best foot forward. The sequence grows increasingly exploitive and mawkish.

But the side trip to Cuba is only one of many elements in this engrossing and (mainly) serious-minded doc. While Sicko is far from the picture of perfect health, it reveals a decidedly more mature and persuasive Michael Moore, a left-wing populist whose self-righteousness can stick in the craw of even his admirers. He is less bombastic this time around, and he wisely limits his onscreen time.

Presented in anamorphic widescreen 1.85:1, Sicko boasts a strong, if unremarkable, picture. Colors are vivid, skin tones realistic. Aside from occasionally soft images, there are no complaints.

The Dolby Digital 5.1 mix doesn't get much of a workout here, but why would it? The sound is clean and crisp, with no distortion or drop-out. Subtitles are available in Spanish and English for the hearing-impaired.

Moore has contributed an array of original material for the DVD special features, which, like the film itself, range from provocative to embarrassing.

Sicko Goes to Washington (8:42) features Moore at a Congressional hearing to voice support for H.R. 676, which would establish a national health insurance plan for eligible families. The clip includes remarks by H.R. 676 author U.S. Rep John Conyers and other lawmakers backing the measure.

This Country Beats France is a travelogue in which Moore presents some of the most progressive governmental policies of Norway, a nation that he says ranks No. 1 in the world for healthcare, literacy, education and per capita income. Clocking it at 10 minutes, it is a fascinating window on a nation with an official state philosopher and prisons that resemble vacations resorts.

Uniquely American (4:37) spotlights the American phenomenon of community fundraisers for people who can't afford their medical bills. The story Moore centers on here is outrageous enough to have warranted inclusion in the film proper.

Similarly, Who Would Jesus Deny? (6:05) is a heartbreaking mini-documentary about a Texas town where nearly 60 percent of the population live below the poverty line. Moore focuses on a cancer patient whose radiation treatment and chemotherapy were suspended when he couldn't afford the out-of-pocket expenses.

More with Mike and Tony Benn (16:17) features more of Tony Benn, a former member of Britain's Parliament and Labor Party leader who appears in Sicko. Regardless of your politics, Benn is an impressive intellect and a mesmerizing speaker. This guy deserves his own documentary.

A Different Kind of Hollywood Premiere (2:44) shows Moore screening Sicko to homeless viewers at Los Angeles' Skid Row. As evidenced in the movie, the blighted urban area has become a favored spot for some hospitals to dump uninsured patients.

An interview gallery features additional clips with three people interviewed in Sicko: Aleida Guevara, daughter of Che Guevara; Harvard law professor Elizabeth Warren; and Marcia Angell, M.D., author of "The Truth about the Drug Companies." Viewers can watch the interviews separately or opt for the "play all" option. The aggregate running time is 26 minutes, 49 seconds.

The special features include a few low points, too. Moore does his annoying naïve-rube routine in What If You Work for G.E. in France (3:27), in which he talks to a French G.E. employee to belabor the point that American companies doing business in France must abide by the laws of that nation. The vignette devolves into some of Moore's trademark corporation-bashing. More unfortunate is Sister Mary Fidel (1:27). In Havana, Moore visits with a Cuban nun who claims there is no religious persecution under Castro's regime. Well, that settles that, Moore seems to say. It's this kind of idiocy that feeds Moore's loudest critics.

Other supplemental material includes a theatrical trailer and "Alone without You" music video performed by The Nightwatchman.

Sicko suffers from the same unevenness of Michael Moore's previous works, vacillating between riveting power and eye-rolling gimmickry. But it is also Moore's most effective and persuasive work to date -- and one that focuses on a problem of grave concern.