A client previously calculated split-half reliability using SPSS and I would like, if possible, to "match" their results in Stata; the scale I am investigating has 17 elements, each scored from 1 to 6; the client provided the following description of what they did in SPSS (in case that helps anyone); they were investigating a different scale:
RELIABILITY
This is from choosing "scale" and "reliability analysis"
/VARIABLES=VAR00001 VAR00002 VAR00003 VAR00004 VAR00005 VAR00006 VAR00007 VAR00008 VAR00009
VAR00010 VAR00011 VAR00012 VAR00013 VAR00014 VAR00015 VAR00016 VAR00017 VAR00018 VAR00019 VAR00020
VAR00021 VAR00022 VAR00023 VAR00024 VAR00025
/SCALE('ALL VARIABLES')
ALL
/MODEL=SPLIT
/ICC=MODEL(MIXED) TYPE(CONSISTENCY) CIN=95 TESTVAL=0.
Here, in the statistics options, I checked the box for "intraclass correlation
coefficient", and I chose the "two-way mixed method" in the model choice, and
"consistency" for the type choice.
****end of quoted material
I have seen Chuck Huber's user's group paper from 2012; but he uses the Spearman-Brown Prophesy formula and I would like to get an ICC if possible
I have looked at the -icc- command but the language on "target" and "rater" is confusing to me (not my area) and my attempts give a very low icc (<.2) which I don't believe to be even close to accurate
So, suggestions welcome (and help with translating the SPSS code above particularly welcome)
added in edit: each patient is given this scale on admission to the facility; I have over 800 facilities and over 600k patients; I do not know who collected the data but all collectors are, allegedly, trained in the use of the scale (in case this helps anyone figure out what "target" and "rater" are)
RELIABILITY
This is from choosing "scale" and "reliability analysis"
/VARIABLES=VAR00001 VAR00002 VAR00003 VAR00004 VAR00005 VAR00006 VAR00007 VAR00008 VAR00009
VAR00010 VAR00011 VAR00012 VAR00013 VAR00014 VAR00015 VAR00016 VAR00017 VAR00018 VAR00019 VAR00020
VAR00021 VAR00022 VAR00023 VAR00024 VAR00025
/SCALE('ALL VARIABLES')
ALL
/MODEL=SPLIT
/ICC=MODEL(MIXED) TYPE(CONSISTENCY) CIN=95 TESTVAL=0.
Here, in the statistics options, I checked the box for "intraclass correlation
coefficient", and I chose the "two-way mixed method" in the model choice, and
"consistency" for the type choice.
****end of quoted material
I have seen Chuck Huber's user's group paper from 2012; but he uses the Spearman-Brown Prophesy formula and I would like to get an ICC if possible
I have looked at the -icc- command but the language on "target" and "rater" is confusing to me (not my area) and my attempts give a very low icc (<.2) which I don't believe to be even close to accurate
So, suggestions welcome (and help with translating the SPSS code above particularly welcome)
added in edit: each patient is given this scale on admission to the facility; I have over 800 facilities and over 600k patients; I do not know who collected the data but all collectors are, allegedly, trained in the use of the scale (in case this helps anyone figure out what "target" and "rater" are)
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