Thank you, Mike, so much for this helpful video. What would one do if they do have predictors that are time-dependent (significant T_COV*Var interaction)?
@Mike Crowson Dear Dr Mike How to include mean and median survival time with the output of a multivariate Cox proportional hazard analysis in SPSS (or SAS, if you have the syntax)? My model has 7 covariates. A hazard ratio for one covariate is therefore adjusted for other covariates in the model. The mean and median values given with Kaplan Meier (KM) curves are for unadjusted survival curves because KM allows only a one-covariate analysis (univariate). Thank you in advance.
Nice informative video. The question, what is the selection criteria for including variables in the multivariate analysis model? I can see some insignificant p values in the current model. Thx in advance.
Hi there. To tell you the truth, I don't really know all the reasoning behind Luke and Homan's (1988) decisions behind inclusion of all the predictors in this model. This isn't really my area of research. Ordinarily, the choice of which variables to include would be based on well-reasoned theory and perhaps bolstered by previous suggestive findings. Nevertheless, even seemingly good theoretical reasoning may not results in findings that are significant. Thanks for visiting and your question! Cheers!
Hello. At the 6:29 mark, you stated that some people may used a transformed version of time. Why would one use the natural log of time [i.e., LN(T_)]? I've read that it is commonly used by some, but none of the sources explain "why." I'm assuming if you use the natural log of time to test the assumption, you must use it in your final model, right? If these questions are too much to explain here, then if you could point me in the direction of another resource (website, textbook, or journal article) that would be great!
thankyou very much, but i have a problem, what if my value have more than 2. For example : in your "group" coded 0 = detox only 1 = partial detox, 2 = treatment, with that i cant get HR result huhuhu
HI, I am using data from a prospective cohort study and I am conducting survival analysis. I have several models and for each of them I have to calculate HR, CIs, number of cases and the person-time. how can I calculate the person time in spss?
Thank you! Very helpful. Do you think other tests such as log minus log plot and residual plots are necessary in addition to check the proportionality assumption over time?
Thank you for this video! If the observation period is 30 days, how can number of weeks take up to 30 weeks then? I'm asking because I have data with variable observation durations, and I want to know if taking observation_duration as a covariate is a good way of dealing with this variability.
Thank you very much for the video! I have a question, what tests should I do to measure the influence of a set of variables on the occurrence of a phenomenon in the absence and / or combination of them? I'm working on my thesis and I'm trying to find patterns in the interaction of this variables. I would really appreciate your help
Thanks for your video it was very helpful. Just one doubt. What means the significant value of the referent dummy variable (Symptom3)? (Variables of he question box). is it the significance of the variable in the equation? Becuase i understand thar the other significants values is comparation with the reference. is That ok ? Thank you again.
This is the best video I have come across on the topic. Plus you give very clear interpretations. Thanks for sharing.
Impressive amount of info in this video thanks!
I have got a great lesson from your presentation. Thank you!
Great video! Thank you!
So nice to attach the powerpoint as well!
Thank you, Mike, so much for this helpful video. What would one do if they do have predictors that are time-dependent (significant T_COV*Var interaction)?
Specifically, I have two continuous variables (SES and a stress exposure variable) that are each significant w/ time.
@Mike Crowson
Dear Dr Mike
How to include mean and median survival time with the output of a multivariate Cox proportional hazard analysis in SPSS (or SAS, if you have the syntax)?
My model has 7 covariates. A hazard ratio for one covariate is therefore adjusted for other covariates in the model. The mean and median values given with Kaplan Meier (KM) curves are for unadjusted survival curves because KM allows only a one-covariate analysis (univariate).
Thank you in advance.
Great video, thank you so much!
You helped me so much! Thanks! :D
This is very helpful! Do you have an example on how to write results for a cox-regression survival analysis?
Very good video! How about if there are 4 groups in the group variable? Thanks in advance!
Nice informative video. The question, what is the selection criteria for including variables in the multivariate analysis model? I can see some insignificant p values in the current model. Thx in advance.
Hi there. To tell you the truth, I don't really know all the reasoning behind Luke and Homan's (1988) decisions behind inclusion of all the predictors in this model. This isn't really my area of research. Ordinarily, the choice of which variables to include would be based on well-reasoned theory and perhaps bolstered by previous suggestive findings. Nevertheless, even seemingly good theoretical reasoning may not results in findings that are significant. Thanks for visiting and your question! Cheers!
@@mikecrowson2462 Thanks for your input.Appreciate it.
How can I check assumption of cox regression model?
Hello. At the 6:29 mark, you stated that some people may used a transformed version of time. Why would one use the natural log of time [i.e., LN(T_)]? I've read that it is commonly used by some, but none of the sources explain "why." I'm assuming if you use the natural log of time to test the assumption, you must use it in your final model, right? If these questions are too much to explain here, then if you could point me in the direction of another resource (website, textbook, or journal article) that would be great!
logarithm compresses original data, it helps in several ways
What if chi square is not significant ? For both categorical variable (last and first) hazard ratio is same.How to interpret it?
thankyou very much, but i have a problem, what if my value have more than 2. For example : in your "group" coded 0 = detox only 1 = partial detox, 2 = treatment, with that i cant get HR result huhuhu
4:28 what if b is 0 for a covariate?
Thanks.. Very helpful
thank you very much! your videos are very helpful!
Can SPSS run other models of Cox regression for clustered data like shared shared frailty?
HI, I am using data from a prospective cohort study and I am conducting survival analysis. I have several models and for each of them I have to calculate HR, CIs, number of cases and the person-time. how can I calculate the person time in spss?
Thank you! Very helpful. Do you think other tests such as log minus log plot and residual plots are necessary in addition to check the proportionality assumption over time?
Thank you for this video!
If the observation period is 30 days, how can number of weeks take up to 30 weeks then?
I'm asking because I have data with variable observation durations, and I want to know if taking observation_duration as a covariate is a good way of dealing with this variability.
Thank you very much for the video!
I have a question, what tests should I do to measure the influence of a set of variables on the occurrence of a phenomenon in the absence and / or combination of them? I'm working on my thesis and I'm trying to find patterns in the interaction of this variables.
I would really appreciate your help
Thanks for your video it was very helpful.
Just one doubt. What means the significant value of the referent dummy variable (Symptom3)? (Variables of he question box). is it the significance of the variable in the equation?
Becuase i understand thar the other significants values is comparation with the reference. is That ok ?
Thank you again.
I am so sorry Professor. I can' t download the ppt file as well as data.
Hi Kraiwut, the links should now be fixed so you can download the data and Powerpoint. Best wishes.
@@mikecrowson2462 Thank you so much.
Great !
was very helpful indeed
Thanks!
very informative