Hi: I am working on a study. It has been planned to do multiple imputation for missing values related to the primary endpoint by an agency's requirements. I have read many materials online and have some ideas. But, I am still not sure. Study information: The study's indication is Epilepsy. Each patient is given a diary and they are supposed to record how many seizures they expeirenced each day during the study period (DB period is ~ 85 days). As you can image, some patients may forget to record their seizures on some days and some patients may discontinue from the study before the Day 85. So there are missing values for seizure counts on some days for some subjects. My questions: 1. Our missing type is considered as 'missing as random' and so this procedure(Proc MI) can be used, correct? 2. Since our missing data is only in one variable, i.e., seizure count, so I think I should NOT use the methods in SAS documentation (Imputation Methods, Table 5) with 'monotone', correct? 3. Since our data is 'seizure count', which should follow poission distribution (correct?), not normal, I should NOT use methods with 'MCMC' since MCMC method is based on the assumption of multivariate normal distribution (MVN) for variables, correct? 4. Then I thought I should use FCS, fcs reg, or fcs regpmm. I read SAS documentation, it has "The predictive mean matching method ensures that imputed values are plausible; it might be more appropriate than the regression method if the normality assumption is violated (Horton and Lipsitz 2001, p. 246)." So I thought I should use 'fcs regpmm'. I also tried 'fcs reg', the imputed values gives non-integer, a number with decimal. It seems it does not fit my case. Our seizure is an count; so it should be an interger. If I use 'fcs regpmm', the imputed values are integers. 5. If using 'fcs regpmm' is correct for my case, what number of 'k' (SAS option with 'fcs regpmm' option) should I pick? Here is the code I use. proc mi data = post nimpute = 25 out = post_mi seed = 54321 noprint; by subjid; var qsdy count;' fcs regpmm (/k = 5); run; Note: 'qsdy' is the study Day variable; it is from Day 1 till Day 85. 'count' is seizure count for each day. There are missings in this variable. Note: since the imputation is by subjid, so covariates such as age, treatment, etc, are not needed (no change for an individual), correct? If any detailed information is needed for this discussion, please ask me. Thanks a lot in advance. Xiaoshu
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Anyone can help with following question? Thanks. In the logistic regression model, b1 is the coefficient of natural log transformed variable x, it is not the coefficient of original scale of x. logit (p/(1-p)) = b0+ b1 In (x) If b1=0.1, What is the OR for one unit increase in the natural log of x (e^0.1)? What is the OR for one unit increase in original scale of X? What is the OR for 5-unit increase in natural log of x ( ? What is the OR for 5-unit increase in X?
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Hi all,
Whenever I import my data into SAS, this note below. Any ways around keeping the original data type when using proc import. Thanks.
NOTE: One or more variables were converted because the data type is not supported by the V9 engine. For more details, run with options MSGLEVEL=I.
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Hi all, I have some code that uses proc hpbin in SAS Viya, however everytime I try to run it in my environment - we get an error message saying that there is insufficient resources to proceed. I have tried breaking down the dataset into smaller chunks and using do loops but still have the same error. Are there any likely causes code wise or this just an environment issue? Also, are there any alternatives to using proc hpbin to perform binning? Thanks
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I have got the SAS re-installed in my personal laptop. Earlier when I used to open a new file whether it is a SAS data file or a SAS code, they used to open in separate windows. However, now when I open any kind of SAS files, all the files get clubbed under one window and within the process flow as shown in the attached screenshot. This makes it quite difficult to see these different files separately or at the same time. Could anyone please help me resolve this issue? Thanks
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