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| Anees Pari posted on Thursday, April 07, 2016 - 7:09 am
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Dear Dr.Muthén,
Hello there. I am exploring whether generic preference based health related quality of measures are appropriate to use in conjunction with disease specific scales in severe mental illness. I have three individual scales that measure depression, mania and generic quality of life respectively in a cohort of patients.
I would like to know whether these instruments measure a common construct/s. All the three scales are unidirectional.To begin with, I ran EFA and found out there a three factor model is appropriate based on parallel plot and loading.
However, I notice that some of the items had negative loading on factors. This was the same case for ESEM and CFA. My questions are:
a) How to interpret negative loadings on factors
b)My sample has got repeated measurements on same individuals (there is no particular periodicity or pattern to their responses; some have sent their responses weekly, some monthly). I would like to use clustered standard errors to adjust for this clustering. In total , i have around 1400 observations on the three scales completed by 100 patients. Is there any way to do this in MPLUS?
I am new to MPLUS and factor analyses, and would be grateful for your advice.
Many thanks
Best wishes
Pari |
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a) When the factor value increases the factor indicator (or its probability) decreases. So just like regression.
b) You can use Analysis Type=Complex EFA. See UG. |
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| Anees Pari posted on Friday, April 08, 2016 - 7:02 am
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Thanks for your prompt response. I tried using the type complex but unable to get a solution and getting the following error
Data:
File is G:\examples.dat ;
variable:
Names are subjid item1 item2 item3 item4 item5 item6;
USEV=item1 item2 item3 item4 item5 item6;
IDVARIABLE =subjid;
CLUSTER=subjid;
Analysis:
Type=COMPLEX EFA 1 2;
OUTPUT: SAMPSTAT MODINDICES(10.00) STAND
*** ERROR
Cluster variable SUBJID has multiple uses.
Could you please advice where I am going wrong? |
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| Anees Pari posted on Friday, April 08, 2016 - 7:08 am
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Further to my above query, I also tried running a CFA but again getting some errors
File is G:\examples.dat ;
variable:
Names are subjid item1 item2 item3 item4 item5 item6;
USEV=item1 item2 item3 item4 item5 item6;
IDVARIABLE =subjid;
CLUSTER=subjid;
Analysis:
Type = complex;
MODEL: difficulty BY item1 item2 item3;
laziness BY item4 item5 item6 ;
OUTPUT: SAMPSTAT MODINDICES(10.00) STAND RESIDUAL TECH2;
PLOT: TYPE = PLOT1 PLOT2 PLOT3;
*** ERROR in VARIABLE command
TYPE=COMPLEX requires a cluster variable, a stratification variable
or replicate weights. Use the CLUSTER, STRATIFICATION or REPWEIGHTS
options to specify one of the requirements for TYPE=COMPLEX.
Thanks again for your help
Best wishes |
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| Subjid can be on either the CLUSTER statement or the IDVARIABLE statement but not both. If you have further error messages, send the output and your license number to support@statmodel.com. |
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