On Mon, 14 Jun 2010 23:09:17 -0700, Mike Wiliams wrote: >The ANAM battery is far too sensitive for a general application like >this.
What are the specificity and sensitivity for the ANAM? Also, what do you mean by "too sensitive"? One interpretation is that it is good at detecting cases with brain injury (sensitivity) while the article suggests that it produces false positives (i.e., 1 - specificity). >In addition, the base rate of TBI among returning soldiers is >so low that a screening with a test like this will be far too >expensive for what it is intended to do. Please explain this to me. From what I have heard, the rate of TBI is much higher than (a) that experienced in previous wars and (b) in the general population. If TBI can be researched in these groups, why shouldn't it be researched in soldiers from Iraq and Afghanistan? If I interpret the article correctly, the pretesting and posttesting was part of an ongoing study which can be interpreted as gathering baseline data under different conditions and in different groups. This seems to me like a worthwhile thing to do unless the ANAM has really bad diagnostic accuracy which raises the question of why it was chosen in the first place. In any event, the premature cancellation of posttests means that the pretest data makes it much more difficult to reach any conclusions at all (outside of supporting the confirmation bias).. >The obvious approach is to only test soldiers who have >some history of head injury, especially those who were rendered >unconscious. Do they really expect that soldiers serving in low >risk assignments will come back with a brain injury and PTSD? Although I agree that soldiers with a documented case of head injury or concussion should be used but you seem to suggest that multiple control groups should not be used. I assume that prettesting will identify a certain percentage of people with pre-existing problems -- are soldiers with pre-existing conditions more likely to develop worsening symptoms after combat experience relative to soldier with pre-existing conditions who were given clerical or noncombat assignments? How to soldiers with pre-existing problems differ from those soldiers who pretest "normal" but manifest abnormalities on posttest? If pretest "normals" can be divided into groups on the basis of combat experience (i.e., involved in combat vs. no involvement), type of wounding experiences (i.e., brain involvement vs other body parts), and so on, how do these differ on posttest as well as other variables, such as diagnosis of TBI and PTSD? There are many ways to slice this data pie and I think it premature to think that we know everything we need to know about this situation. As for whether soldiers with low risk assignments will come back with brain injury and PTSD, we'll have some relevant data coming from studies of people's reactions to the 9/11 attacks in NYC where comparisons are being made between people immediately involved with the World Trade Center (WTC) and some distance from the WTC site. If memory serves, at least once study has shown that the incidence of PTSD after 9/11 was related to distance from the WTC, with the rate decreasing as distance increased. One did not have to be at the WTC site to have developed PTSD. >The other thing they must include is an assessment of malingering. The >military disability support system is very ripe for abuse. It is a waste of >tax dollars to conduct these assessments without checks on malingering. Perhaps the testing program is set up very badly, with very little thought as to how it should be implemented and what sorts of controls need to be maintained (this seems to be a implication of what you are saying). But the news article provides little info on these points and unless one has the proposal for the program and progress reports on how well it is being implemented, it is very difficult to determine how well it is doing or poorly it is doing. An alternative interpretation as to why the posttest program was stopped is that it actually accurately detects a higher rate of valid cases of TBI then the methods currently in use but because treating such cases is expensive, it is better to keep the detection of such cases low instead of incurring the expense of providing treatment. There is much more we need to know about this situation including (a) if the ANAM is such a lousy screening instrument why was it used and how did the military's IRB allow it and (b) a convincing case for stopping the posttesting has not been made, in my opinion, and move evidence concerning this point needs to be provided. -Mike Palij New York University [email protected] --- You are currently subscribed to tips as: [email protected]. To unsubscribe click here: http://fsulist.frostburg.edu/u?id=13090.68da6e6e5325aa33287ff385b70df5d5&n=T&l=tips&o=3098 or send a blank email to leave-3098-13090.68da6e6e5325aa33287ff385b70df...@fsulist.frostburg.edu
