exactly like Y-BOCS in OCD;

''Full response 35% or greater reduction of Y-BOCS, Partial response Greater than 25% but less than 35% Y-BOCS reduction'

http://ijnp.oxfordjournals.org/content/ijnp/5/2/181.full.pdf

Consider using the SYMPTOMS OF TRAUMA SCALE (SOTS):

Article The Symptoms of Trauma Scale (SOTS)

Perhaps PTSD would be amenable to interventions and diagnostic test similar to that for the retina.

Dear Miraç,

In addition to Lewis' great suggestion, response to treatment could be measured using the self-reported PTSD symptom severity (Impact of Event Scale-Revised). Another option could be the Posttraumatic Stress Diagnostic Scale.

Please see attached for some articles that could be of interest to you.

Best wishes,

Julio

http://www.ncbi.nlm.nih.gov/pubmed/26335088

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4686047/

http://www.psychiatrist.com/jcp/article/Pages/2015/v76n08/v76n0807.aspx

 Thank you Mr. Opler and Mr. Torales for your answers.

( http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4686047/ ) says;

''either showed a poor response (defined as a reduction in PTSD symptoms of no more than a third) or good response (defined as a reduction defined as a reduction in PTSD symptoms of two thirds or greater)''    = means %33.3 reduction in DSM-IV 4 item likert  scale is a good response. Maybe i can use %30 symptom reduction for ''good response''

One strategy is to utilise effect size for evaluating interventions or alternatively consider pre post 'p' value.

there is evidence that even in the presence of elevated PCL-C scores there can be improvement in quality of life, the issue is not just reduction PTSD scores but measures quality of life etc

 I agree with you Mr. Crompton, but i want to corralate biological parameters like cortisol, DHEA etc with flashbacks maybe, how can i say patient relieved from flashbacks or avoidance or negative thinking ? ( of course there will confounders like depression etc.)

There are a number of measures that you can consider including CAPS 5, PCL-C or M, DES, DASS, there are instruments that assess phobic avoidance and you may consider Schema Questionairre

CAPS 5 and PCL 5 are gold standard and are being used with DSM5/ICD10.

Technical Report (PLEASE READ ABSTRACT BEFORE REQUESTING) Pynoos, R. S., Weat...

Article Psychometric Properties of the PTSD Checklist for Diagnostic...

Mirac,

One very simple way of assessing a good/bad response to PTSD treatment is to ask if the sufferer has returned to, or remained in, their job.

Bw

Chris

Thank you for your answers; i checked almost all questionaries and semi-structered forms of PTSD including  CAPS 5, PCL-C, DES, DASS, PTSD-I etc. but i m looking for a test that gives me dichotomous (responded or not , like in depression or ocd trials) variables that i can run ROC analysis.  

 The convention in all research on psychopharm for PTSD has defined a response as 30% response in a standardized measure.  That lower threshold for delta scores is supposed to reflect the difficulty of getting a response for PTSD.

A dichotomous decision is best obtained from the shortest scales. Two 4-item scales exist for PTSD: Breslau's Short Screening Scale and the Primary Care PTSD Screen (PC-PTSD)

Best of all then would be the Single-item PTSD Screener (SIPS). Quoting from its development: "The final selected item for the screen was, “Were you recently bothered by a past experience that caused you to believe you would be injured or killed?”. Response options include not bothered at all, bothered a little, or bothered a lot."

Follow-ups would presumable be reworded for the index incident to ask "How bothered are you now by (index incident) etc.?" Arguably any change in response would be categorical and equate to 33% improvement (or worsening) on average.

Here is another article RE: SOTS.

Article The Symptoms of Trauma Scale (SOTS): Psychometric Evaluation...

Defining treatment response in single event PTSD is difficult. Interpreting what it means on some binary level is likely subject to misinterpretation due to its imprecise nature.  Do you mean reduction in symptoms?  For how long?  Mean time between symptom experiences?  Is the underlying interpretation that response to treatment is equivalent to cure (return to pre-exposure baseline)?  Avoidance and reactivity may be relatively easy to assess, but intrusive behaviors and emotions are probably more likely event based rather than time based.  Response to treatment in the intrusion domain may be difficult to assess using a self-report questionnaire.  Response to treatment may be much more related to which triggers have been desensitized.  Since neither the therapist nor the patient may be aware of those triggers, it may be impossible to make a measure of response to treatment.  Measurement is rarely categorical or binary.  It is not about whether, it is about how much.  I suspect that in the complex milleau of PTSD domains, a change in one due to therapy is a response to therapy.  But does that tell the story we want to tell?  To paraphrase Einstein, we want our measures to be as simple as possible, but not simpler. 

My concern has to do with funding sources and policy makers who want to see immediate results of response to treatment for those diagnosed with PTSD (or any other condition, for that matter.)  Most phase oriented trauma treatment protocols start with establishing safety, trust and rapport, as well as self-soothing behaviors and coping skills development.  Only then does the therapist work directly toward desensitizing PTSD triggers and eliminating other PTSD behaviors.  I have found that too often the response to treatment starting at phase II rather than Phase I results in the patient bolting from therapy and taking a "flight into health."  That is a failed therapy!  But when one spends weeks to years to create safety and do the other things associated with Phase I insurers don't get to see response to therapy in reduction of PTSD symptoms and they consider an ongoing healthy therapeutic alliance and overall working therapy as an inadequate response and terminate funding the therapy.  Perhaps any measure of response to therapy needs to incorporate our theoretical orientation toward that therapy and our conceptualization of the patient.  The social, economic and political impact of our use of measures carries some obligation to properly interpret them in an appropriate context.  To look for one global omnibus measure of PTSD victims response to therapy begs oversimplification and misunderstanding.  I hope that we don't add to that misunderstanding.

I realize that my response to your question does not answer it directly.  If you assume that the scale is linear and of interval level, perhaps the best is not to report that there is or is not a response to treatment, but rather something like the following.  " The patient today reported a 50 point reduction from baseline in symptoms of PTSD on the PTSD-I scale." Or you could just put into your note that the patient scored a "27 today on the PTSD-X scale.  A graph over time would probably be more revealing.  You might also just indicate that the patient is feeling (better, the same or worse) since the last session."  You could also have the patient make a subjective non-specific evaluation of symptoms and turn that into an intervention of self-efficacy, as well.  For example, "On a scale of 0 to 100 how are you doing today with regard to your PTSD?"  When the patient replies, say "I'm really crappy today at about a 40."  You have your measure and can add the intervention as follows:  "Wow!  You are at a 40.  What are you doing to make it a 40 rather than a 30?"  This is not the time to ask "What do you need to do to make it a 50."

Please don't make the measure fit the analysis tool, make the tool fit the best description the data can provide."  This is much too serious to be held hostage by the requirements of a computer program.  Others may have a different opinion.

Dear Mr. Drehmer,

       First of all, thank you for your comphrensive answer, as a junior clinican i totally agree with you. We want to think psychiatry/psychology as a biological science and so we are copying the other medical areas like endocrinology/diabetus. If you have diabetus and more than %6 Hba1c in your blood, you have a bad blood sugar regulation, if you have less you are treated well. That is also arguable and im not a expert of internal medicine but this test is easy, useful, generalizeable and mostly reflects the real situation. And yes, our self-reports and other clinician administered PTSD measurements are not enough to understand patients changing negative self image, functionality in therapy, maybe. Also everyone responds a therapy somehow and we dont know future results of PTSD therapy for now.

       I want a binary result of a therapy ( if it is possible or not, not sure) because i will be using biological measurements also (like DHEA, cortisol, NPY etc.). thank you again for reminding and confrontaion of how hard to measure PTSD symptoms and treatment response.