David, it seems like what you are saying is that statistically, it's possible to identify ALL variables affecting patient outcomes but piratically speaking, there's little applicability? Is this an accurate assessment?
----- Original Message ----- From: Lehman, David <[EMAIL PROTECTED]> Sent: Thursday, August 03, 2006 To: [email protected] <[email protected]> Subj: [OTlist] FW: Interesting Stats LD> Ron! It would require me to draw pictures with LD> explanations....just draw a bunch of circles that represent every LD> person in a population and then make sure each circle crosses over LD> another circle it has things common with but, the circle is free LD> of those things not common with the original circle. Then, look LD> at all the circles and how each crosses over with other circles - LD> the parts of the circle that are not overlapping with another LD> circle represents unique variables for each person in the LD> population. Then calculate the space that each circle has free LD> versus each part of the circle that overlaps with other circles. LD> That is your multivariate picture of how much is similar and LD> fifferent for each circle. The thing is that you choose all those LD> variables you listed previously as well as any and all variables LD> that people have. You would eventually see the unique portion of LD> each circle minimize into something that probably is not LD> significant in the outcome you wish to acheive with that LD> particular individual. LD> Get it? LD> ________________________________ LD> From: [EMAIL PROTECTED] on behalf of Ron Carson LD> Sent: Thu 8/3/2006 2:46 PM LD> To: Lehman, David LD> Subject: Re: [OTlist] FW: Interesting Stats LD> WAY, WAY, WAY, over my head. LD> David, please decipher!!! LD> Ron LD> ----- Original Message ----- LD> From: Lehman, David <[EMAIL PROTECTED]> LD> Sent: Monday, July 31, 2006 LD> To: [email protected] <[email protected]> LD> Subj: [OTlist] FW: Interesting Stats LD>> Ron...from our buddy Dan...have fun with this one. LD>> ________________________________ LD>> From: Lofald, Dan [mailto:[EMAIL PROTECTED] LD>> Sent: Mon 7/31/2006 2:00 PM LD>> To: Lehman, David; Ron Carson LD>> Subject: RE: [OTlist] Interesting Stats LD>> Howdy David, Howdy Ron LD>> We might not be sitting at the lunch table but the good conversation continues. LD>> As the Irish saying goes, "Is this a private fight or can anyone join" LD>> It appears to be that there are about 6 different concepts in play. LD>> David's comments about taking all of the variables en' mass LD>> and seeing what regression would tell us. LD>> Yep-folks do this all of the time. For example, I was LD>> involved trying to find lead indicators of newborn deaths at Univ. LD>> of Florida Hospital. There were 1400 independent variables and 1 LD>> dependent variable (death/life). LD>> We hunted around for months looking for best predictive sets LD>> of predictors. The approach to this work was, "if it works, it LD>> works." However, this is nothing more than mainframe level data LD>> grubbing. It can never tell us anything scientifically definitive LD>> because the alpha level is astronomical. However, it might give LD>> insight on a place to look with tools that are more sophisticated. LD>> Invariably, meaningful finds with first-order relationships LD>> are rare events. The good stuff is going to emerge out of finding LD>> important suppressor and mediator variables at work. In addition, LD>> most of the variables will probably not be in a linear LD>> relationship with each other (especially not with human beings). LD>> With regression, you can check for suppressor and mediator LD>> variables and you can test polynomial solutions --- however-to get LD>> to the good stuff, we would probably have use multi-variate tools. LD>> At the broader level - the two of you have an ontological & LD>> mathematical conversation combined (I love it). LD>> Let's look at the passage, "All humans are unique." What LD>> does that statement mean? Every part of every human is unlike LD>> every part of every other human? If that were the case, and we LD>> used Set Theory, we would have 121 billion non-intersecting LD>> circles. If that were the case, not only would science be LD>> impossible, but so also preclude the possibility of language and LD>> culture. LD>> If by, "All humans are unique," we mean, that some part of my LD>> circle does not overlap with your circle - we are now onto LD>> something important. Now we can ask how much of our two Venn LD>> circles overlap and do not overlap. This is expression we have LD>> with a Pearson product-moment correlation of p = .80, which means LD>> that 64% of the variance in one variable can be predicted by the LD>> variance of the other circle. LD>> But what happens when there are ten of us. How do our LD>> circles overlap now (we are talking about the ephemeral LD>> phenomological/psychological variables that you guys are talking LD>> about). If we look at enough people can we find patterns among LD>> what initially appeared discretely idiosyncratic? LD>> [[Oh gee - I cannot finish this response this week but I LD>> should would like to take it up with you guys another time. You LD>> are drilling down to one of the most interesting and important LD>> pieces of social science. LD>> Dan LD>> Daniel R. Lofald, PhD LD>> Staff Development Coordinator LD>> Chippewa Valley Technical College LD>> 620 W. Clairemont Ave., Eau Claire, WI 54701-6162 LD>> Phone 715-852-1328 Fax 715-833-6451 LD>> ________________________________ LD>> From: Lehman, David [mailto:[EMAIL PROTECTED] LD>> Sent: Wednesday, July 26, 2006 8:54 PM LD>> To: Lofald, Dan LD>> Subject: FW: [OTlist] Interesting Stats LD>> Ron remembers you.....well! LD>> More thoughts? LD>> ________________________________ LD>> From: [EMAIL PROTECTED] on behalf of Ron Carson LD>> Sent: Wed 7/26/2006 8:42 PM LD>> To: Lehman, David LD>> Subject: Re: [OTlist] Interesting Stats LD>> Given that you have a PhD, and if I remember, you and Dan L. LD>> frequently talked about this stuff, I feel that I am definitely LD>> out-classed!! <lol>. But, being the brave, (uh, stupid) person that I LD>> am, I will continue wading in the deep end of the pool. LD>> It seems that regression analysis looks at individual variables. But LD>> we know that people are not just collection of individual variables. LD>> We are after all, greater then the sum of our parts. LD>> How does regression analysis look at the SUM of the variables? LD>> Also, is it possible to quantify a subjective feeling? I know this is LD>> done with pain scales, but the subjective nature of such scales LD>> renders them almost useless for comparisons sake. In other words, my LD>> reported pain of 9 is total meaningless when COMPARED to your reported LD>> pain of 9. LD>> Lastly, just because someone has a history of any of the variables, in LD>> and of itself, that history is meaningless. For example, just because LD>> someone has a history of total hip arthroplasty, that doesn't mean LD>> they will need adaptations to dress their lower body. LD>> Ok, one more "lastly". You said: david>>> The more variables, the more chances for your results occuring david>>> because of poor internal validity LD>> Are you saying that the greater the number of variables, the less LD>> likely you can predict the results? If so, they I maintain that the LD>> number of variable affecting patient outcomes is infinite and thus you LD>> can never truly predict the outcomes. Keep in mind that I refer to LD>> patients, not to procedures. LD>> Ron LD>> ----- Original Message ----- LD>> From: Lehman, David <[EMAIL PROTECTED]> LD>> Sent: Wednesday, July 26, 2006 LD>> To: [email protected] <[email protected]> LD>> Subj: [OTlist] Interesting Stats LD>>> I am not surprised you disagree, Ron! Thats what makes us get along so well! LD>>> I think you walked right into what I wanted to get across: LD>>> Each of the variables you listed below can be measured, LD>>> right? If something (a dependent or attribute variable) can be LD>>> measured, then it has a number which can then be used to determine LD>>> if the unique variable is significant , and this is the important LD>>> part, I think, that when using a regression analysis, it takes LD>>> into account all the other unique and not unique variables thought LD>>> to be a contributor to the healing (increased functional LD>>> activities, increased occupation). LD>>> So, if one individual, has a history of any or most of these, LD>>> then how does that effect your treatment versus if she had 30% LD>>> relevant, or 10% relevant, etc... The more variables, the more LD>>> chances for your results occuring because of poor internal LD>>> validity (poor job controlling all the other variablesvariables) - LD>>> and you dont know if it were treatment approach a or b or c or d LD>>> or e.....or placebo. LD>>> OK...I am going statistical here and trying to explain LD>>> it..,.....but, if you can quantify something, you can study its LD>>> relationship with other variables and outcomes. LD>>> This is fun. LD>>> ________________________________ LD>>> From: [EMAIL PROTECTED] on behalf of Ron Carson LD>>> Sent: Wed 7/26/2006 7:31 PM LD>>> To: Lehman, David LD>>> Subject: Re: [OTlist] Interesting Stats LD>>> Hello David: LD>>> I hate to disagree but every person has unique variables. That's what LD>>> makes us unique. And perhaps the greatest and uniqueness variable of LD>>> all is the subjective feeling and experiences associated with injury, LD>>> disease and illness. It is in fact that subjective experience of our LD>>> patient's that makes being an OT so difficult. LD>>> Regarding a list, here's a few: LD>>> age, gender, marital status, employment history, race, religion, LD>>> medical history, current medications, spiritual beliefs, family LD>>> support, financial support, cognitive status, mental status, LD>>> education, prior experience with OT, expectations, diet, sleep LD>>> patterns, do they have regular bowel movements, etc. LD>>> The list is truly endless!! LD>>> This is a GREAT topic LD>>> Ron LD>>> ----- Original Message ----- LD>>> From: Lehman, David <[EMAIL PROTECTED]> LD>>> Sent: Wednesday, July 26, 2006 LD>>> To: [email protected] <[email protected]> LD>>> Subj: [OTlist] Interesting Stats LD>>>> I mis-spoke, perhaps....meaning that there really are no LD>>>> unique variables that ONLY exist to one person on earth. If LD>>>> enough data is gathered on a population, the "unique" or should I LD>>>> say less appearing variables we call unique, would be detectable LD>>>> and the statistical model would show us what contribution that LD>>>> particular "unique variable" makes and if it is significant in the LD>>>> outcome. LD>>>> I guess my next question would be to ask the members to list LD>>>> variables they consider unique to a person that have an impact on LD>>>> the treatment they provide. LD>>>> ________________________________ LD>>>> From: [EMAIL PROTECTED] on behalf of Ron Carson LD>>>> Sent: Wed 7/26/2006 4:04 PM LD>>>> To: Lehman, David LD>>>> Subject: Re: [OTlist] Interesting Stats LD>>>> I don't know much, if anything, about regression theory, but I'm LD>>>> pretty confident that it is impossible to take into account ALL the LD>>>> UNIQUE variables that account for healing. Also, it seems rather LD>>>> counterintuitive to try include a "unique" variable into a "general" LD>>>> logarithm. LD>>>> Ron LD>>>> ----- Original Message ----- LD>>>> From: Lehman, David <[EMAIL PROTECTED]> LD>>>> Sent: Wednesday, July 26, 2006 LD>>>> To: [email protected] <[email protected]> LD>>>> Subj: [OTlist] Interesting Stats LD>>>>> all of the unique variables of LD>>>>> a client could one day be analysed in a regression model LD>>>>> and thus determine how much these LD>>>>> unique variables actually account for healing, then LD>>>>> include them in the logaritm? LD>>>> -- LD>>>> Unsubscribe? LD>>>> [EMAIL PROTECTED] LD>>>> Change options? LD>>>> www.otnow.com/mailman/options/otlist_otnow.com LD>>>> Archive? LD>>>> www.mail-archive.com/[email protected] LD>>>> Help? LD>>>> [EMAIL PROTECTED] LD>>> -- LD>>> Unsubscribe? LD>>> [EMAIL PROTECTED] LD>>> Change options? LD>>> www.otnow.com/mailman/options/otlist_otnow.com LD>>> Archive? LD>>> www.mail-archive.com/[email protected] LD>>> Help? LD>>> [EMAIL PROTECTED] LD>> -- LD>> Unsubscribe? LD>> [EMAIL PROTECTED] LD>> Change options? LD>> www.otnow.com/mailman/options/otlist_otnow.com LD>> Archive? LD>> www.mail-archive.com/[email protected] LD>> Help? LD>> [EMAIL PROTECTED] LD> -- LD> Unsubscribe? LD> [EMAIL PROTECTED] LD> Change options? LD> www.otnow.com/mailman/options/otlist_otnow.com LD> Archive? LD> www.mail-archive.com/[email protected] LD> Help? LD> [EMAIL PROTECTED] -- Unsubscribe? 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