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https://communities.sas.com/kntur85557/tracker
ph6 TrackerWed, 07 Aug 2024 12:54:11 GMT2024-08-07T12:54:11ZRe: Sample size calculation for repeated measure
https://communities.sas.com/t5/Statistical-Procedures/Sample-size-calculation-for-repeated-measure/m-p/768989#M37610
<P>Thanks a lot for this link. Indeed very helpful. I have a pilot study from which I would like to estimate the error standard deviation and correlation matrix. I use </P>
<P>```</P>
<P>proc corr data = ccl2_t;<BR />var _0 _12 _24 _36 _48;<BR />run;</P>
<P>```</P>
<P>to obtain the correlations but I get some negative values which do not suit for the proc glmpower. Do you know how that can be fixed? How can I simply enter the correlation matrix?</P>
<P>For the error standard deviation I simply find the SD of the mean differences. Is that a right approach?</P>Wed, 22 Sep 2021 01:54:34 GMThttps://communities.sas.com/t5/Statistical-Procedures/Sample-size-calculation-for-repeated-measure/m-p/768989#M37610ph62021-09-22T01:54:34ZSample size calculation for repeated measure
https://communities.sas.com/t5/Statistical-Procedures/Sample-size-calculation-for-repeated-measure/m-p/768783#M37597
I need to calculate the sample size for a study of biomarkers which indicate the progress of a disease. The samples will be collected at baseline, 12, 24,36 and 48 months and will be tested against 15 CSF biomarkers. A pilot study has been done with 15 patients which I would like to use as prior information. I believe that the biomarkers are independent but there also could be some correlation. The study question is to see if the continuous measurements of each biomarker changes over time. The biomarkers values are not normally distributed. I have tried Gpower software using non parametric Anova for repeated measure. My first question is whether I need to calculate the sample size for each biomarker individually using Bonferroni correction 0.05/15 and then choose the largest sample size, or to calculate the sample size for all biomarkers together. Another question, for the gpower I would need, no sphericity correction, epsilon, correlation between time points and eta square, I tried to calculate them using proc glm, as<BR /><BR />proc glm data=data;<BR />class timepoint;<BR />model biom= ...<BR />repeated timepoint/ Printe;<BR />run;<BR /><BR />But didn't get what I want. Do you know how can I obtain those values and shall I assume data for each biomarker separately?Tue, 21 Sep 2021 13:51:13 GMThttps://communities.sas.com/t5/Statistical-Procedures/Sample-size-calculation-for-repeated-measure/m-p/768783#M37597ph62021-09-21T13:51:13ZRe: How to estimate standard error for the reference category in proc glm?
https://communities.sas.com/t5/Statistical-Procedures/How-to-estimate-standard-error-for-the-reference-category-in/m-p/723192#M35059
I am designing a macro which could calculate the group means and SEs for a linear regression with categorical exposures. Is there any other way to find the group estimates, as it is hard to adjust the estimate statement when we have different number of categories?Wed, 03 Mar 2021 16:29:54 GMThttps://communities.sas.com/t5/Statistical-Procedures/How-to-estimate-standard-error-for-the-reference-category-in/m-p/723192#M35059ph62021-03-03T16:29:54ZHow to estimate standard error for the reference category in proc glm?
https://communities.sas.com/t5/Statistical-Procedures/How-to-estimate-standard-error-for-the-reference-category-in/m-p/723058#M35051
<P>I use proc glm to find the estimates for a categorical variable with 3 levels; rs1 : {1,2,3}</P>
<P>I have identified level 1 as the reference category. I would like to find the standard error for the reference category</P>
<P>so that I could form CIs for it as well.</P>
<P>I use the following code:</P>
<P> </P>
<PRE><CODE class=" language-sas">PROC GLM DATA=AllData PLOTS=NONE;
CLASS rs1(ref = '1');
MODEL nmr_acace = rs1 /CLPARM SOLUTION E;
estimate 'rs1 1' intercept 1 rs1 1 0 0 ;
QUIT;</CODE></PRE>
<P>I get the following results:</P>
<PRE> Estimate standard error
rs1 0 0.007628342 0.00335261
rs1 2 -0.000113952 0.00833655
rs1 1 0.000 .
Estimate standard error
rs1 1 3.05314364 0.00183197
</PRE>
<P>I do not know how to interpret the estimate for rs1 = 1 being 3.053. I was hoping to have it as 0 and by the standard error find the confidence intervals for it. </P>
<P> </P>
<P> </P>Wed, 03 Mar 2021 02:19:44 GMThttps://communities.sas.com/t5/Statistical-Procedures/How-to-estimate-standard-error-for-the-reference-category-in/m-p/723058#M35051ph62021-03-03T02:19:44ZRe: How to modify 'proc glm' in sas to find estimates per 10 units or per SD unit change of the expo
https://communities.sas.com/t5/Statistical-Procedures/How-to-modify-proc-glm-in-sas-to-find-estimates-per-10-units-or/m-p/722854#M35043
Would it be OK to divide x by 10, and standardize the SDs before running the model?Tue, 02 Mar 2021 13:12:37 GMThttps://communities.sas.com/t5/Statistical-Procedures/How-to-modify-proc-glm-in-sas-to-find-estimates-per-10-units-or/m-p/722854#M35043ph62021-03-02T13:12:37ZRe: How to modify 'proc glm' in sas to find estimates per 10 units or per SD unit change of the expo
https://communities.sas.com/t5/Statistical-Procedures/How-to-modify-proc-glm-in-sas-to-find-estimates-per-10-units-or/m-p/722750#M35029
Thank you, what if I have logistic regression?Tue, 02 Mar 2021 00:37:14 GMThttps://communities.sas.com/t5/Statistical-Procedures/How-to-modify-proc-glm-in-sas-to-find-estimates-per-10-units-or/m-p/722750#M35029ph62021-03-02T00:37:14ZRe: How to modify 'proc glm' in sas to find estimates per 10 units or per SD unit change of the expo
https://communities.sas.com/t5/Statistical-Procedures/How-to-modify-proc-glm-in-sas-to-find-estimates-per-10-units-or/m-p/722738#M35027
<P>.</P>Tue, 02 Mar 2021 00:43:31 GMThttps://communities.sas.com/t5/Statistical-Procedures/How-to-modify-proc-glm-in-sas-to-find-estimates-per-10-units-or/m-p/722738#M35027ph62021-03-02T00:43:31ZRe: How to modify 'proc glm' in sas to find estimates per 10 units or per SD unit change of the expo
https://communities.sas.com/t5/Statistical-Procedures/How-to-modify-proc-glm-in-sas-to-find-estimates-per-10-units-or/m-p/722631#M35016
Thank you so much. For the SD do you have any thoughts how could modify the data?Mon, 01 Mar 2021 17:31:44 GMThttps://communities.sas.com/t5/Statistical-Procedures/How-to-modify-proc-glm-in-sas-to-find-estimates-per-10-units-or/m-p/722631#M35016ph62021-03-01T17:31:44ZHow to modify 'proc glm' in sas to find estimates per 10 units or per SD unit change of the exposure
https://communities.sas.com/t5/Statistical-Procedures/How-to-modify-proc-glm-in-sas-to-find-estimates-per-10-units-or/m-p/722628#M35014
<P>I am using proc glm in SAS to find the estimates per unit change of exposure for the response variables. How could I modify my code so that it would calculate the estimates per 10 units or per SD change of the exposure variables? Here is my code:</P>
<PRE><CODE> PROC GLM DATA=MyData PLOTS=NONE;
CLASS &ClassAdj;
MODEL &TraitList = &PVar &ClassAdj &ContAdj / SOLUTION E;
%IF &ByVars ^= %THEN BY &ByVars;;
QUIT;
</CODE></PRE>
<P> </P>Mon, 01 Mar 2021 17:20:28 GMThttps://communities.sas.com/t5/Statistical-Procedures/How-to-modify-proc-glm-in-sas-to-find-estimates-per-10-units-or/m-p/722628#M35014ph62021-03-01T17:20:28ZRe: How to combine two columns in new rows in SAS?
https://communities.sas.com/t5/SAS-Programming/How-to-combine-two-columns-in-new-rows-in-SAS/m-p/666856#M199594
I tried your code, it works but removes the first row of the levels, <BR /><BR />variable value<BR />-------------------<BR />Age_group<BR />2 0.3<BR />3 0.2<BR />4 0.5Fri, 03 Jul 2020 15:52:59 GMThttps://communities.sas.com/t5/SAS-Programming/How-to-combine-two-columns-in-new-rows-in-SAS/m-p/666856#M199594ph62020-07-03T15:52:59ZRe: How to combine two columns in new rows in SAS?
https://communities.sas.com/t5/SAS-Programming/How-to-combine-two-columns-in-new-rows-in-SAS/m-p/666788#M199568
I want to report this, but I am using a macro for outputing and need to have the data ready with one column which includes the variable and its levels.Fri, 03 Jul 2020 11:39:27 GMThttps://communities.sas.com/t5/SAS-Programming/How-to-combine-two-columns-in-new-rows-in-SAS/m-p/666788#M199568ph62020-07-03T11:39:27ZRe: How to combine two columns in new rows in SAS?
https://communities.sas.com/t5/SAS-Programming/How-to-combine-two-columns-in-new-rows-in-SAS/m-p/666687#M199513
This made no change into my data..Thu, 02 Jul 2020 19:38:24 GMThttps://communities.sas.com/t5/SAS-Programming/How-to-combine-two-columns-in-new-rows-in-SAS/m-p/666687#M199513ph62020-07-02T19:38:24ZRe: How to combine two columns in new rows in SAS?
https://communities.sas.com/t5/SAS-Programming/How-to-combine-two-columns-in-new-rows-in-SAS/m-p/666656#M199502
I want variable to be in a separate blank row as in my question.Thu, 02 Jul 2020 17:57:15 GMThttps://communities.sas.com/t5/SAS-Programming/How-to-combine-two-columns-in-new-rows-in-SAS/m-p/666656#M199502ph62020-07-02T17:57:15ZRe: How to combine two columns in new rows in SAS?
https://communities.sas.com/t5/SAS-Programming/How-to-combine-two-columns-in-new-rows-in-SAS/m-p/666653#M199499
Thanks, but I want is to combine the two columns, not only removing variable.Thu, 02 Jul 2020 17:43:00 GMThttps://communities.sas.com/t5/SAS-Programming/How-to-combine-two-columns-in-new-rows-in-SAS/m-p/666653#M199499ph62020-07-02T17:43:00ZHow to combine two columns in new rows in SAS?
https://communities.sas.com/t5/SAS-Programming/How-to-combine-two-columns-in-new-rows-in-SAS/m-p/666644#M199494
<P>Hi, I have a dataset as follows:</P>
<P> </P>
<PRE><CODE class=" language-sas">variable level value
-----------------------
Age_group 1 0.1
Age_group 2 0.3
Age_group 3 0.2
Age_group 4 0.5</CODE></PRE>
<P><BR /><BR />I would like to reformat it to get,</P>
<P> </P>
<PRE><CODE class=" language-sas">variable value
-------------------
(^\b Age_group)
1 0.1
2 0.3
3 0.2
4 0.5</CODE></PRE>
<P> </P>
<P>Is there any way to perform this?</P>Thu, 02 Jul 2020 16:45:12 GMThttps://communities.sas.com/t5/SAS-Programming/How-to-combine-two-columns-in-new-rows-in-SAS/m-p/666644#M199494ph62020-07-02T16:45:12ZRe: How to combine three datasets with same variables in SAS?
https://communities.sas.com/t5/SAS-Programming/How-to-combine-three-datasets-with-same-variables-in-SAS/m-p/654050#M196466
It works, but I needed to put by a also in the update statement. Thank you!Sun, 07 Jun 2020 17:47:38 GMThttps://communities.sas.com/t5/SAS-Programming/How-to-combine-three-datasets-with-same-variables-in-SAS/m-p/654050#M196466ph62020-06-07T17:47:38ZHow to combine three datasets with same variables in SAS?
https://communities.sas.com/t5/SAS-Programming/How-to-combine-three-datasets-with-same-variables-in-SAS/m-p/654042#M196461
<P>Hi, I have three datasets,</P><PRE><CODE class=" language-sas">data1
A B C D
1 8 7 9
2 0 . .
3 . . .
data2
A B C D
1 8 . .
2 0 5 0
3 . . .
data3
A B C D
1 8 . .
2 0 . .
3 . 7 4</CODE></PRE><P>I need to combine these three datasets keeping A, B the same and combining C and D variables.</P><PRE><CODE class=" language-sas">All
A B C D
1 8 7 9
2 0 5 0
3 . 7 4</CODE></PRE><P>I am using merge, but it does not produce what I want:</P><PRE>data all;
merge data1 data2 data3;
run;</PRE><P>Any ideas how can I perform this action?</P>Sun, 07 Jun 2020 16:50:07 GMThttps://communities.sas.com/t5/SAS-Programming/How-to-combine-three-datasets-with-same-variables-in-SAS/m-p/654042#M196461ph62020-06-07T16:50:07ZIncluding all treatments in crossover design mixed model in SAS
https://communities.sas.com/t5/SAS-Programming/Including-all-treatments-in-crossover-design-mixed-model-in-SAS/m-p/646517#M193431
<P>Hi, I have a dataset effects of 3 treatments against ctrl on cell-lines collected from 4 donors.</P><P>```<BR />Treatment donor value log_val<BR />Ctrl D1 xx<BR />T1 D2 xx<BR />T2 D3 xx<BR />T4 D4 xx<BR />```<BR />I would like to compare the effects of treatments against ctrl and also with each other using a mixed model. I use the following mixed model in SAS:<BR />```<BR />PROC MIXED data=data;<BR />CLASS DONOR TREATMENT;<BR />MODEL log_val= TREATMENT/ DDFM=SATTERTH;<BR />random DONOR ;<BR />LSMEANS TREATMENT / PDIFF CL E;<BR />estimate 'T/R' TREATMENT -1 1 / cl ;<BR />run;<BR />```</P><P>When I include all the treatments in one model I am getting higher standard errors than the case if I include only two treatments which I want to compare for different combinations of treatments. Which approach should I choose? Including all the treatments as once or including two treatments and repeating for different combinations?</P>Sun, 10 May 2020 15:17:34 GMThttps://communities.sas.com/t5/SAS-Programming/Including-all-treatments-in-crossover-design-mixed-model-in-SAS/m-p/646517#M193431ph62020-05-10T15:17:34ZProc glimmix does not converge
https://communities.sas.com/t5/SAS-Programming/Proc-glimmix-does-not-converge/m-p/630106#M186484
<P>I have a dataset with two variables, first variable is the test result, it attains values : 1,2,3,4,5. The other one is the golden standard with values 0,1 and missing. I am using the following model to find the effect of the test on the golden standard:</P><P> </P><PRE><CODE class=" language-sas">proc glimmix data=data;
class studyID PosResultDesc ;
model tbyn1 = PosResultDesc/ cl dist=binary or link=logit chisq;
random intercept / subject = studyID ;
run;</CODE></PRE><P>But the model does not converge. I attach the data, any thoughts what could be the reason?</P><P> </P><DIV class="branch"><DIV><DIV align="left"><TABLE><TBODY><TR><TD> </TD></TR></TBODY></TABLE></DIV></DIV></DIV>Fri, 06 Mar 2020 15:33:24 GMThttps://communities.sas.com/t5/SAS-Programming/Proc-glimmix-does-not-converge/m-p/630106#M186484ph62020-03-06T15:33:24ZRe: Logistic regression when there are more than one observation for each subject
https://communities.sas.com/t5/SAS-Programming/Logistic-regression-when-there-are-more-than-one-observation-for/m-p/621459#M182689
<P>Thank you. Using least square means method I am getting negative values for the lower bound of the confidence intervals. Can I report them as they are or replace by zero?</P>Fri, 31 Jan 2020 16:06:44 GMThttps://communities.sas.com/t5/SAS-Programming/Logistic-regression-when-there-are-more-than-one-observation-for/m-p/621459#M182689ph62020-01-31T16:06:44Z