tag:blogger.com,1999:blog-2020989200831574035.post374268320245211154..comments2023-12-13T01:47:38.575-05:00Comments on The New Life of e-Patient Dave: Don't let the median scare you to deathe-Patient Davehttp://www.blogger.com/profile/11608258246509102466noreply@blogger.comBlogger2125tag:blogger.com,1999:blog-2020989200831574035.post-73753704194823954182009-12-21T16:01:53.171-05:002009-12-21T16:01:53.171-05:00PNSchmidt,
To amplify this - in my particular cas...PNSchmidt,<br /><br />To amplify this - in my particular case, Stage IV kidney cancer, most people who are diagnosed at that stage are indeed in big trouble. I found a short questionnaire online that asked questions like "have you been losing your appetite," which graded by condition. From that answer (I think it was the Karnofsky Performance Scale) I looked up the median time.<br /><br />Only later, <i>through my ACOR patient community</i>, did I learn that those numbers were <i>obsolete</i> - the data was all collected in the early 1990s. <br /><br />That's just another example of why the "best available" information may not be USEFUL information. It still comes down to "Okay, what are my options?" Knowing the odds aren't good is just a motivator.e-Patient Davehttps://www.blogger.com/profile/11608258246509102466noreply@blogger.comtag:blogger.com,1999:blog-2020989200831574035.post-455761351613161632009-12-21T09:32:06.703-05:002009-12-21T09:32:06.703-05:00Dave- this is a difficult (mathematical) topic. F...Dave- this is a difficult (mathematical) topic. First of all, most medical statistics are interpreted incorrectly. I was just at a conference where they presented a distribution by the mean and standard deviation, however 100% of the data was less than one standard deviation above the mean. If data isn't normally distributed, standard deviation is meaningless. Let's take mean. If a disease kills 90% of those affected instantly but 10% live 50 years more, the mean survival time is 5 years. Does that tell you anything? Further, studies on survival include death by causes other than the disease. In Parkinson's disease, the median survival after diagnosis is 12 years, but 50% die from causes other than PD. In diseases that predominantly affect the elderly, it is important to consider the median age at diagnosis. One of the simplest ways to get a sense of a distribution is to see both the median and the mean. A difference between the two shows a skew in the distribution.<br /><br />My advice for anyone who is told a single statistic about a disease is to recognize that you've been told nothing. Any physician who doesn't know a disease well would be best off not trying to characterize it on the basis of a single metric. To understand survivability, you need to understand not just the survivorship curve of a disease but also the profile of typical patient on diagnosis (not just their age and general health but also the stage of their disease) and how the current patient deviates from that profile, and the therapies of the typical patient versus the therapies available to your current patient. If your doc doesn't tell you these things, ask; if she doesn't know, she ought to have been more careful about telling you the info in the first place.pnschmidthttp://twitter.com/pnschmidtnoreply@blogger.com