/* Code for SF-6D from version 2 of the SF-12.  Uses values from Brazier JE, Roberts JR.  The Estimation of a
Preference-Based Measure of Health From the SF-12.  Medical Care.  42:9;851-859  This code uses values from table 4.

Presumes the conversion from 5 to 2 role categories is the same as for the SF-36 version. 

sf2 = moderate activities where 1="limited a lot" to 3="not limited at all"
sf5 = physical limits kind of work where 1="all of the time" to 5="none of the time"
sf6 = emotional accomplish less where 1="all of the time" to 5="none of the time"
sf8 = pain interferes with work where 1="not at all" to 5="extremely"
sf10 = lots of energy where 1="all the time" to 5="none of the time"
sf11 = downhearted where 1="all the time" to 5="none of the time"
sf12 = social activities where 1="all the time" to 5="none of the time"

*/

data sf6d12 ; 
	set 'C:\. . .';
run;

/*recode 5 item response in version2 to 2 item response of version1 */

data sf6d12;
	set sf6d12;
	
if 0<sf5<5 then sf5=1;
if sf5=5 then sf5=2;
if 0<sf6<5 then sf6=1;
if sf6=5 then sf6=2;
run;

data SF6D12;
	set SF6D12;
	sf6d=1;
	if sf2=1 then sf6d=sf6d-.045;
	if sf6=1 or sf5 = 1 then sf6d=sf6d-.063;
	if sf12=4 then sf6d=sf6d-.063;
	if sf12 =3 then sf6d=sf6d-.066;
	if sf12=2 then sf6d=sf6d-.081;
	if sf12=1 then sf6d=sf6d-.093;
	if sf8=3 then sf6d=sf6d-.042;
	if sf8=4 then sf6d=sf6d-.077;
	if sf8=5 then sf6d=sf6d-.137;
	if sf11=4 or sf11=3 then sf6d=sf6d-.059;
	if sf11=2 then sf6d=sf6d-.113;
	if sf11=1 then sf6d=sf6d-.134;
	if sf10=2 or sf10=3 or sf10=4 then sf6d=sf6d-.078;
	if sf10=5 then sf6d=sf6d-.106;

	
	if sf2= 1 or sf6 = 1 or sf12 =1 or sf12=2 or sf8=4 or sf8=5 or sf11=2 or sf11=1 or sf10=6 then sf6d=sf6d-.077;
	
	if sf2= . or sf5=. or sf6=. or sf12=. or sf11=. or sf10=. then sf6d=. ;
run;