Issue with my code

[Fadams12]

Hello,

I have a problem with this code; I don't understand why it does not pick fire-related incidents.
Steps a and b are to show whether the hospitalization is related to CO poisoning yes or no
step c is to identify fire-related CO poisoning; I think either step c or step f has a problem, but I am not sure what it is because I expect to see fire-related incidents, but as it is, it returns nothing for fire-related incidents.
All other parts seem to be working well!
If anyone can identify something that may be off, I would appreciate it!

* sub-step A;
substr(dx18,1,5) in ('T5801', 'T5804', 'T5811', 'T5814', 'T5891', 'T5894') or substr(dx17,1,6) in ('T582X1', 'T582X4', 'T588X1', 'T588X4') then COyes_step2a10 = 1;
* sub-step B;
substr(dx18,1,5) in ('T5802', 'T5803', 'T5812', 'T5813', 'T5892', 'T5893') or substr(dx17,1,6) in ('T582X2', 'T582X3', 'T588X2', 'T588X3') then COno_step2b10 = 1;

if COyes_step2a10 = 1 and COno_step2b10 ~= 1 then COpoisoning = 1;

* sub-step c;
substr(dx18,1,3) in ('X00', 'X01', 'X02', 'X03', 'X04', 'X05', 'X06', 'X08') then CO_fire10 = 1;
 
* sub-step d;
substr(dx18,1,5) in ('T5801', 'T5811', 'T5891') or substr(dx17,1,6) in ('T582X1', 'T588X1') then CO_nonfire_prelim10 = 1; 

if CO_fire10 ~= 1 and CO_nonfire_prelim10 = 1 then CO_nonfire10 = 1;

* sub-step e;

substr(dx18,1,5) in ('T5804', 'T5814', 'T5894') or substr(dx17,1,6) in ('T582X4', 'T588X4') then CO_unknown_prelim1_10 = 1;

if CO_fire10 ~= 1 and CO_unknown_prelim1_10 = 1 then CO_unknown_prelim2_10 = 1;
		if CO_fire10 = 1 and CO_nonfire10 = 1 then CO_unknown_prelim3_10 = 1;
		if CO_unknown_prelim2_10 = 1 or CO_unknown_prelim3_10 = 1 then CO_unknown10 = 1;

		* sub-step f;
		if CO_fire10 = 1 then Cause = 1;*fire related ;
		if CO_nonfire10 = 1 then Cause = 2;*not fire related;
		if CO_unknown10 = 1 then Cause = 3;*Unknown mechanism or intent;
			if CO_fire10 = 1 and CO_nonfire10 = 1 then Cause = 3;
			if CO_fire10 = 1 and CO_unknown10 = 1 then Cause = 3;
			if CO_nonfire10 = 1 and CO_unknown10 = 1 then Cause = 3;
          HealthOutcomeID=3;
          MonthlyHosp=0;
			run;

[Tom]

I suspect you meant those first few to be IF/THEN/ELSE statements.

Not SUBSTR() = statements.