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* File      HALCyon cognitive syntax_Lothian1921.do
* BY        Rebecca Hardy, MRC Unit for Lifelong Health and Ageing at UCL
* FOR       HALCyon cross-cohort collaboration (funded by the New Dynamics of Ageing (RES-353-25-0001))
* DATASET   Lothian 1921
* Date Created    07/04/2010
* PURPOSE         Recodes and derives cognitive variables for use in cross-cohort analyses
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# delimit;
set more off;



/*********************************************************************************/

/*Crystallized cognitive ability*/
/*NART*/
/*range 0-50*/
gen nart_w1=nart79 ;
label variable nart_w1 "NART at wave 1 (age 79)" ;
gen nart_w2=nart83 ;
label variable nart_w2 "NART at wave 2 (age 83)" ;

/*standardise NART to whole sample*/
egen nartz_w1=std(nart_w1) ;
label variable nartz_w1 "standardised NART at wave 1 (age 79)" ;
egen nartz_w2=std(nart_w2) ;
label variable nartz_w2 "standardised NART at wave 2 (age 83)" ;

/*standardise NART for men and women seprately*/
egen nartzm_w1=std(nart_w1) if sex==1;
egen nartzf_w1=std(nart_w1) if sex==2;
label variable nartzm_w1 "standardised NART for men at wave 1 (age 79)" ;
label variable nartzf_w1 "standardised NART  for women at wave 1 (age 79)" ;
egen nartzm_w2=std(nart_w2) if sex==1;
egen nartzf_w2=std(nart_w2) if sex==2;
label variable nartzm_w2 "standardised NART for men at wave 2 (age 83)" ;
label variable nartzf_w2 "standardised NART  for women at wave 2 (age 83)" ;
/*combine in one variable*/
gen nartzs_w1=. ;
replace nartzs_w1=nartzm_w1 if sex==1;
replace nartzs_w1=nartzf_w1 if sex==2;
label variable nartzs_w1 "sex-standardised NART at wave 1 (age 79)" ;
gen nartzs_w2=. ;
replace nartzs_w2=nartzm_w2 if sex==1;
replace nartzs_w2=nartzf_w2 if sex==2;
label variable nartzs_w2 "sex-standardised NART at wave 2 (age 83)" ;

/*verbal fluency*/
/*range 0-80*/
gen vftotal_w1=vftot79 ;
label variable vftotal_w1 "Total verbal fluency score at wave 1 (age 79)" ;
gen vftotal_w2=vtotal83 ;
label variable vftotal_w2 "Total verbal fluency score at wave 2 (age 83)" ;

/*standardised verbal fluency total*/
egen vftotalz_w1=std(vftotal_w1) ;
label variable vftotalz_w1 "standardised total verbal fluency at wave 1 (age 79)" ;
egen vftotalz_w2=std(vftotal_w2) ;
label variable vftotalz_w2 "standardised total verbal fluency at wave 2 (age 83)" ;

/*standardise NART for men and women seprately*/
egen vftotalzm_w1=std(vftotal_w1) if sex==1;
egen vftotalzf_w1=std(vftotal_w1) if sex==2;
label variable vftotalzm_w1 "standardised total verbal fluency for men at wave 1 (age 79)" ;
label variable vftotalzf_w1 "standardised total verbal fluency  for women at wave 1 (age 79)" ;
egen vftotalzm_w2=std(vftotal_w2) if sex==1;
egen vftotalzf_w2=std(vftotal_w2) if sex==2;
label variable vftotalzm_w2 "standardised total verbal fluency for men at wave 2 (age 83)" ;
label variable vftotalzf_w2 "standardised total verbal fluency for women at wave 2 (age 83)" ;
/*combine in one variable*/
gen vftotalzs_w1=. ;
replace vftotalzs_w1=vftotalzm_w1 if sex==1;
replace vftotalzs_w1=vftotalzf_w1 if sex==2;
label variable vftotalzs_w1 "sex-standardised total verbal fluency at wave 1 (age 79)" ;
gen vftotalzs_w2=. ;
replace vftotalzs_w2=vftotalzm_w2 if sex==1;
replace vftotalzs_w2=vftotalzf_w2 if sex==2;
label variable vftotalzs_w2 "sex-standardised total verbal fluency at wave 2 (age 83)" ;

/* Raven's Matrices*/
/*range 0-60*/
gen ravens_w1=ravens ;
label variable ravens_w1 "Ravens Matrices score at wave 1 (age 79)" ;
gen ravens_w2=ravens83 ;
label variable ravens_w2 "Ravens Matrices score at wave 2 (age 83)" ;

/*standardise Raven's scores */
egen ravensz_w1=std(ravens_w1) ;
label variable ravensz_w1 "standardised Ravens Matrices score at wave 1 (age 79)" ;
egen ravensz_w2=std(ravens_w2) ;
label variable ravensz_w2 "standardised Ravens Matrices score at wave 2 (age 83)" ;

/*standardise Raven's Matrices score for men and women seprately*/
egen ravenszm_w1=std(ravens_w1) if sex==1;
egen ravenszf_w1=std(ravens_w1) if sex==2;
label variable ravenszm_w1 "standardised Raven's Matrices score for men at wave 1 (age 79)" ;
label variable ravenszf_w1 "standardised Raven's Matrices score for women at wave 1 (age 79)" ;
egen ravenszm_w2=std(ravens_w2) if sex==1;
egen ravenszf_w2=std(ravens_w2) if sex==2;
label variable ravenszm_w2 "standardised Raven's Matrices score for men at wave 2 (age 83)" ;
label variable ravenszf_w2 "standardised Raven's Matrices score for women at wave 2 (age 83)" ;
/*combine in one variable*/
gen ravenszs_w1=. ;
replace ravenszs_w1=ravenszm_w1 if sex==1;
replace ravenszs_w1=ravenszf_w1 if sex==2;
label variable ravenszs_w1 "sex-standardised Raven's Matrices score at wave 1 (age 79)" ;
gen ravenszs_w2=.;
replace ravenszs_w2=ravenszm_w2 if sex==1;
replace ravenszs_w2=ravenszf_w2 if sex==2;
label variable ravenszs_w2 "sex-standardised Raven's Matrices score at wave 2 (age 83)" ;

/*Wechsler logical memory*/
/*range 0-75*/
gen logmem_w1=logmem79 ;
label variable logmem_w1 "Logical Memory score at wave 1 (age 79)" ;
gen logmem_w2=logtot83 ;
label variable logmem_w2 "Logical Memory score at wave 2 (age 83)" ;

/*standardise logical memory score */
egen logmemz_w1=std(logmem_w1) ;
label variable logmemz_w1 "standardised Logical Memory score at wave 1 (age 79)" ;
egen logmemz_w2=std(logmem_w2) ;
label variable logmemz_w2 "standardised Logical Memory score at wave 2 (age 83)" ;

/*standardise logical memory score for men and women seprately*/
egen logmemzm_w1=std(logmem_w1) if sex==1;
egen logmemzf_w1=std(logmem_w1) if sex==2;
label variable logmemzm_w1 "standardised logical memory score for men at wave 1 (age 79)" ;
label variable logmemzf_w1 "standardised logical memory score for women at wave 1 (age 79)" ;
egen logmemzm_w2=std(logmem_w2) if sex==1;
egen logmemzf_w2=std(logmem_w2) if sex==2;
label variable logmemzm_w2 "standardised logical memory score for men at wave 2 (age 83)" ;
label variable logmemzf_w2 "standardised logical memory score  for women at wave 2 (age 83)" ;
/*combine in one variable*/
gen logmemzs_w1=. ;
replace logmemzs_w1=logmemzm_w1 if sex==1;
replace logmemzs_w1=logmemzf_w1 if sex==2;
label variable logmemzs_w1 "sex-standardised logical memory score at wave 1 (age 79)" ;
gen logmemzs_w2=.;
replace logmemzs_w2=logmemzm_w2 if sex==1;
replace logmemzs_w2=logmemzf_w2 if sex==2;
label variable logmemzs_w2 "sex-standardised logical memory score at wave 2 (age 83)" ;

/*derive fluid cognitive ability - Gf*/
factor vftotalz_w1 ravensz_w1 logmemz_w1, factors(1) pcf ;
predict Gf_w1 ;
label variable Gf_w1 "Gf at wave 1 (age 79)" ;
factor vftotalz_w2 ravensz_w2 logmemz_w2, factors(1) pcf ;
predict Gf_w2 ;
label variable Gf_w2 "Gf at wave 2 (age 83)" ;