*# var # Replaces invalid icd9 codes with missing ("") 
*! 29aug2007 
program icd9clear 
version 9.2 
syntax varlist 
 
local i 1 
local test: char _dta[note`i'] 
while ~mi("`test'") { 
	local test: char _dta[note`++i'] 
	} 
 
foreach v of varlist `varlist' { 
	tempvar bad 
	icd9 check `v', g(`bad') 
	replace `v'="" if `bad' 
	capture drop `bad' 
	} 
 
notes drop _dta in `i'/`=`i'+100' //as of 9/20/06 there are 32 icd9 notes 
end