litwin: the u.s.preventive services task force said that at the population level, we shouldn't be spending money on screening, 'cause the evidence doesn't support it. researchers look at the outcomes. are the men who were screened regularly for prostate cancer more likely to be alive and not having died from prostate cancer? and the answer was no. for the physician, all the incentives are just to do it. if i don't do it, and you end up with prostate cancer, you're going to be very mad at me and you're going to-- you might sue me, and you're certainly going to think i cost you your life. you're going to be very, very unhappy. if i do it and i do no benefit to you, the test is normal, you'll still think i'm a good, savvy doctor. if i do it and i do worse than that, it gets a false positive and i end up doing all sorts of interventions, and you end up impotent for something that you had no reason ever to undergo in the first place, you're still going to thank me. you're going to say, "whew. the doctor sa