Hi, I am working with HCUP NIS data files. I get "using required". I don't know why!
/************************************************** ***************************
* Stataload_NIS_2014_Core.Do
* This program will load the 2014 NIS ASCII Core File into Stata.
* Because Stata loads the entire file into memory, it may not be possible
* to load every data element for large files. If necessary, edit this
* program to change the memory size or to load only selected data elements.
************************************************** ***************************/

*** Set available memory size ***
set mem 500m

*** Read data elements from the ASCII file ***
infix int AGE 1- 3 ///
byte AGE_NEONATE 4- 5 ///
byte AMONTH 6- 7 ///
byte AWEEKEND 8- 9 ///
byte DIED 10- 11 ///
double DISCWT 12- 22 ///
byte DISPUNIFORM 23- 24 ///
byte DQTR 25- 26 ///
int DRG 27- 29 ///
int DRG24 30- 32 ///
byte DRGVER 33- 34 ///
int DRG_NoPOA 35- 37 ///
str DX1 38- 42 ///
str DX2 43- 47 ///
str DX3 48- 52 ///
str DX4 53- 57 ///
str DX5 58- 62 ///
str DX6 63- 67 ///
str DX7 68- 72 ///
str DX8 73- 77 ///
str DX9 78- 82 ///
str DX10 83- 87 ///
str DX11 88- 92 ///
str DX12 93- 97 ///
str DX13 98- 102 ///
str DX14 103- 107 ///
str DX15 108- 112 ///
str DX16 113- 117 ///
str DX17 118- 122 ///
str DX18 123- 127 ///
str DX19 128- 132 ///
str DX20 133- 137 ///
str DX21 138- 142 ///
str DX22 143- 147 ///
str DX23 148- 152 ///
str DX24 153- 157 ///
str DX25 158- 162 ///
str DX26 163- 167 ///
str DX27 168- 172 ///
str DX28 173- 177 ///
str DX29 178- 182 ///
str DX30 183- 187 ///
int DXCCS1 188- 190 ///
int DXCCS2 191- 193 ///
int DXCCS3 194- 196 ///
int DXCCS4 197- 199 ///
int DXCCS5 200- 202 ///
int DXCCS6 203- 205 ///
int DXCCS7 206- 208 ///
int DXCCS8 209- 211 ///
int DXCCS9 212- 214 ///
int DXCCS10 215- 217 ///
int DXCCS11 218- 220 ///
int DXCCS12 221- 223 ///
int DXCCS13 224- 226 ///
int DXCCS14 227- 229 ///
int DXCCS15 230- 232 ///
int DXCCS16 233- 235 ///
int DXCCS17 236- 238 ///
int DXCCS18 239- 241 ///
int DXCCS19 242- 244 ///
int DXCCS20 245- 247 ///
int DXCCS21 248- 250 ///
int DXCCS22 251- 253 ///
int DXCCS23 254- 256 ///
int DXCCS24 257- 259 ///
int DXCCS25 260- 262 ///
int DXCCS26 263- 265 ///
int DXCCS27 266- 268 ///
int DXCCS28 269- 271 ///
int DXCCS29 272- 274 ///
int DXCCS30 275- 277 ///
str ECODE1 278- 282 ///
str ECODE2 283- 287 ///
str ECODE3 288- 292 ///
str ECODE4 293- 297 ///
byte ELECTIVE 298- 299 ///
int E_CCS1 300- 303 ///
int E_CCS2 304- 307 ///
int E_CCS3 308- 311 ///
int E_CCS4 312- 315 ///
byte FEMALE 316- 317 ///
int HCUP_ED 318- 320 ///
byte HOSPBRTH 321- 322 ///
byte HOSP_DIVISION 323- 324 ///
long HOSP_NIS 325- 329 ///
double KEY_NIS 330- 339 ///
long LOS 340- 344 ///
byte MDC 345- 346 ///
byte MDC24 347- 348 ///
byte MDC_NoPOA 349- 350 ///
byte NCHRONIC 351- 352 ///
byte NDX 353- 354 ///
int NECODE 355- 357 ///
byte NEOMAT 358- 359 ///
int NIS_STRATUM 360- 363 ///
byte NPR 364- 365 ///
byte ORPROC 366- 367 ///
byte PAY1 368- 369 ///
int PL_NCHS 370- 372 ///
str PR1 373- 376 ///
str PR2 377- 380 ///
str PR3 381- 384 ///
str PR4 385- 388 ///
str PR5 389- 392 ///
str PR6 393- 396 ///
str PR7 397- 400 ///
str PR8 401- 404 ///
str PR9 405- 408 ///
str PR10 409- 412 ///
str PR11 413- 416 ///
str PR12 417- 420 ///
str PR13 421- 424 ///
str PR14 425- 428 ///
str PR15 429- 432 ///
int PRCCS1 433- 435 ///
int PRCCS2 436- 438 ///
int PRCCS3 439- 441 ///
int PRCCS4 442- 444 ///
int PRCCS5 445- 447 ///
int PRCCS6 448- 450 ///
int PRCCS7 451- 453 ///
int PRCCS8 454- 456 ///
int PRCCS9 457- 459 ///
int PRCCS10 460- 462 ///
int PRCCS11 463- 465 ///
int PRCCS12 466- 468 ///
int PRCCS13 469- 471 ///
int PRCCS14 472- 474 ///
int PRCCS15 475- 477 ///
int PRDAY1 478- 480 ///
int PRDAY2 481- 483 ///
int PRDAY3 484- 486 ///
int PRDAY4 487- 489 ///
int PRDAY5 490- 492 ///
int PRDAY6 493- 495 ///
int PRDAY7 496- 498 ///
int PRDAY8 499- 501 ///
int PRDAY9 502- 504 ///
int PRDAY10 505- 507 ///
int PRDAY11 508- 510 ///
int PRDAY12 511- 513 ///
int PRDAY13 514- 516 ///
int PRDAY14 517- 519 ///
int PRDAY15 520- 522 ///
byte RACE 523- 524 ///
int SERVICELINE 525- 527 ///
double TOTCHG 528- 537 ///
byte TRAN_IN 538- 539 ///
byte TRAN_OUT 540- 541 ///
int YEAR 542- 545 ///
byte ZIPINC_QRTL 546- 547 ///
using "C:\Users\mjafaribidgoli\Desktop\HCUP\HCUP_NIS_201 4\NIS_2014_Core.ASC"

*** Assign labels to the data elements ***
label var AGE "Age in years at admission"
label var AGE_NEONATE "Neonatal age (first 28 days after birth) indicator"
label var AMONTH "Admission month"
label var AWEEKEND "Admission day is a weekend"
label var DIED "Died during hospitalization"
label var DISCWT "NIS discharge weight"
label var DISPUNIFORM "Disposition of patient (uniform)"
label var DQTR "Discharge quarter"
label var DRG "DRG in effect on discharge date"
label var DRG24 "DRG, version 24"
label var DRGVER "DRG grouper version used on discharge date"
label var DRG_NoPOA "DRG in use on discharge date, calculated without POA"
label var DX1 "Diagnosis 1"
label var DX2 "Diagnosis 2"
label var DX3 "Diagnosis 3"
label var DX4 "Diagnosis 4"
label var DX5 "Diagnosis 5"
label var DX6 "Diagnosis 6"
label var DX7 "Diagnosis 7"
label var DX8 "Diagnosis 8"
label var DX9 "Diagnosis 9"
label var DX10 "Diagnosis 10"
label var DX11 "Diagnosis 11"
label var DX12 "Diagnosis 12"
label var DX13 "Diagnosis 13"
label var DX14 "Diagnosis 14"
label var DX15 "Diagnosis 15"
label var DX16 "Diagnosis 16"
label var DX17 "Diagnosis 17"
label var DX18 "Diagnosis 18"
label var DX19 "Diagnosis 19"
label var DX20 "Diagnosis 20"
label var DX21 "Diagnosis 21"
label var DX22 "Diagnosis 22"
label var DX23 "Diagnosis 23"
label var DX24 "Diagnosis 24"
label var DX25 "Diagnosis 25"
label var DX26 "Diagnosis 26"
label var DX27 "Diagnosis 27"
label var DX28 "Diagnosis 28"
label var DX29 "Diagnosis 29"
label var DX30 "Diagnosis 30"
label var DXCCS1 "CCS: diagnosis 1"
label var DXCCS2 "CCS: diagnosis 2"
label var DXCCS3 "CCS: diagnosis 3"
label var DXCCS4 "CCS: diagnosis 4"
label var DXCCS5 "CCS: diagnosis 5"
label var DXCCS6 "CCS: diagnosis 6"
label var DXCCS7 "CCS: diagnosis 7"
label var DXCCS8 "CCS: diagnosis 8"
label var DXCCS9 "CCS: diagnosis 9"
label var DXCCS10 "CCS: diagnosis 10"
label var DXCCS11 "CCS: diagnosis 11"
label var DXCCS12 "CCS: diagnosis 12"
label var DXCCS13 "CCS: diagnosis 13"
label var DXCCS14 "CCS: diagnosis 14"
label var DXCCS15 "CCS: diagnosis 15"
label var DXCCS16 "CCS: diagnosis 16"
label var DXCCS17 "CCS: diagnosis 17"
label var DXCCS18 "CCS: diagnosis 18"
label var DXCCS19 "CCS: diagnosis 19"
label var DXCCS20 "CCS: diagnosis 20"
label var DXCCS21 "CCS: diagnosis 21"
label var DXCCS22 "CCS: diagnosis 22"
label var DXCCS23 "CCS: diagnosis 23"
label var DXCCS24 "CCS: diagnosis 24"
label var DXCCS25 "CCS: diagnosis 25"
label var DXCCS26 "CCS: diagnosis 26"
label var DXCCS27 "CCS: diagnosis 27"
label var DXCCS28 "CCS: diagnosis 28"
label var DXCCS29 "CCS: diagnosis 29"
label var DXCCS30 "CCS: diagnosis 30"
label var ECODE1 "E code 1"
label var ECODE2 "E code 2"
label var ECODE3 "E code 3"
label var ECODE4 "E code 4"
label var ELECTIVE "Elective versus non-elective admission"
label var E_CCS1 "CCS: E Code 1"
label var E_CCS2 "CCS: E Code 2"
label var E_CCS3 "CCS: E Code 3"
label var E_CCS4 "CCS: E Code 4"
label var FEMALE "Indicator of sex"
label var HCUP_ED "HCUP Emergency Department service indicator"
label var HOSPBRTH "Indicator of birth in this hospital"
label var HOSP_DIVISION "Census Division of hospital"
label var HOSP_NIS "NIS hospital number"
label var KEY_NIS "NIS record number"
label var LOS "Length of stay (cleaned)"
label var MDC "MDC in effect on discharge date"
label var MDC24 "MDC, version 24"
label var MDC_NoPOA "MDC in use on discharge date, calculated without POA"
label var NCHRONIC "Number of chronic conditions"
label var NDX "Number of diagnoses on this record"
label var NECODE "Number of E codes on this record"
label var NEOMAT "Neonatal and/or maternal DX and/or PR"
label var NIS_STRATUM "NIS hospital stratum"
label var NPR "Number of procedures on this record"
label var ORPROC "Major operating room procedure indicator"
label var PAY1 "Primary expected payer (uniform)"
label var PL_NCHS "Patient Location: NCHS Urban-Rural Code"
label var PR1 "Procedure 1"
label var PR2 "Procedure 2"
label var PR3 "Procedure 3"
label var PR4 "Procedure 4"
label var PR5 "Procedure 5"
label var PR6 "Procedure 6"
label var PR7 "Procedure 7"
label var PR8 "Procedure 8"
label var PR9 "Procedure 9"
label var PR10 "Procedure 10"
label var PR11 "Procedure 11"
label var PR12 "Procedure 12"
label var PR13 "Procedure 13"
label var PR14 "Procedure 14"
label var PR15 "Procedure 15"
label var PRCCS1 "CCS: procedure 1"
label var PRCCS2 "CCS: procedure 2"
label var PRCCS3 "CCS: procedure 3"
label var PRCCS4 "CCS: procedure 4"
label var PRCCS5 "CCS: procedure 5"
label var PRCCS6 "CCS: procedure 6"
label var PRCCS7 "CCS: procedure 7"
label var PRCCS8 "CCS: procedure 8"
label var PRCCS9 "CCS: procedure 9"
label var PRCCS10 "CCS: procedure 10"
label var PRCCS11 "CCS: procedure 11"
label var PRCCS12 "CCS: procedure 12"
label var PRCCS13 "CCS: procedure 13"
label var PRCCS14 "CCS: procedure 14"
label var PRCCS15 "CCS: procedure 15"
label var PRDAY1 "Number of days from admission to PR1"
label var PRDAY2 "Number of days from admission to PR2"
label var PRDAY3 "Number of days from admission to PR3"
label var PRDAY4 "Number of days from admission to PR4"
label var PRDAY5 "Number of days from admission to PR5"
label var PRDAY6 "Number of days from admission to PR6"
label var PRDAY7 "Number of days from admission to PR7"
label var PRDAY8 "Number of days from admission to PR8"
label var PRDAY9 "Number of days from admission to PR9"
label var PRDAY10 "Number of days from admission to PR10"
label var PRDAY11 "Number of days from admission to PR11"
label var PRDAY12 "Number of days from admission to PR12"
label var PRDAY13 "Number of days from admission to PR13"
label var PRDAY14 "Number of days from admission to PR14"
label var PRDAY15 "Number of days from admission to PR15"
label var RACE "Race (uniform)"
label var SERVICELINE "Hospital Service Line"
label var TOTCHG "Total charges (cleaned)"
label var TRAN_IN "Transfer in indicator"
label var TRAN_OUT "Transfer out indicator"
label var YEAR "Calendar year"
label var ZIPINC_QRTL "Median household income national quartile for patient ZIP Code"

*** Convert special values to missing values ***
recode AGE (-99 -88 -66=.)
recode AGE_NEONATE (-9 -8 -6 -5=.)
recode AMONTH (-9 -8 -6 -5=.)
recode AWEEKEND (-9 -8 -6 -5=.)
recode DIED (-9 -8 -6 -5=.)
recode DISCWT (-99.9999999 -88.8888888 -66.6666666=.)
recode DISPUNIFORM (-9 -8 -6 -5=.)
recode DQTR (-9 -8 -6 -5=.)
recode DRG (-99 -88 -66=.)
recode DRG24 (-99 -88 -66=.)
recode DRGVER (-9 -8 -6 -5=.)
recode DRG_NoPOA (-99 -88 -66=.)
recode DXCCS1 (-99 -88 -66=.)
recode DXCCS2 (-99 -88 -66=.)
recode DXCCS3 (-99 -88 -66=.)
recode DXCCS4 (-99 -88 -66=.)
recode DXCCS5 (-99 -88 -66=.)
recode DXCCS6 (-99 -88 -66=.)
recode DXCCS7 (-99 -88 -66=.)
recode DXCCS8 (-99 -88 -66=.)
recode DXCCS9 (-99 -88 -66=.)
recode DXCCS10 (-99 -88 -66=.)
recode DXCCS11 (-99 -88 -66=.)
recode DXCCS12 (-99 -88 -66=.)
recode DXCCS13 (-99 -88 -66=.)
recode DXCCS14 (-99 -88 -66=.)
recode DXCCS15 (-99 -88 -66=.)
recode DXCCS16 (-99 -88 -66=.)
recode DXCCS17 (-99 -88 -66=.)
recode DXCCS18 (-99 -88 -66=.)
recode DXCCS19 (-99 -88 -66=.)
recode DXCCS20 (-99 -88 -66=.)
recode DXCCS21 (-99 -88 -66=.)
recode DXCCS22 (-99 -88 -66=.)
recode DXCCS23 (-99 -88 -66=.)
recode DXCCS24 (-99 -88 -66=.)
recode DXCCS25 (-99 -88 -66=.)
recode DXCCS26 (-99 -88 -66=.)
recode DXCCS27 (-99 -88 -66=.)
recode DXCCS28 (-99 -88 -66=.)
recode DXCCS29 (-99 -88 -66=.)
recode DXCCS30 (-99 -88 -66=.)
recode ELECTIVE (-9 -8 -6 -5=.)
recode E_CCS1 (-999 -888 -666=.)
recode E_CCS2 (-999 -888 -666=.)
recode E_CCS3 (-999 -888 -666=.)
recode E_CCS4 (-999 -888 -666=.)
recode FEMALE (-9 -8 -6 -5=.)
recode HCUP_ED (-99 -88 -66=.)
recode HOSPBRTH (-9 -8 -6 -5=.)
recode HOSP_DIVISION (-9 -8 -6 -5=.)
recode HOSP_NIS (-9999 -8888 -6666=.)
recode KEY_NIS (-999999999 -888888888 -666666666=.)
recode LOS (-9999 -8888 -6666=.)
recode MDC (-9 -8 -6 -5=.)
recode MDC24 (-9 -8 -6 -5=.)
recode MDC_NoPOA (-9 -8 -6 -5=.)
recode NCHRONIC (-9 -8 -6 -5=.)
recode NDX (-9 -8 -6 -5=.)
recode NECODE (-99 -88 -66=.)
recode NEOMAT (-9 -8 -6 -5=.)
recode NIS_STRATUM (-999 -888 -666=.)
recode NPR (-9 -8 -6 -5=.)
recode ORPROC (-9 -8 -6 -5=.)
recode PAY1 (-9 -8 -6 -5=.)
recode PL_NCHS (-99 -88 -66=.)
recode PRCCS1 (-99 -88 -66=.)
recode PRCCS2 (-99 -88 -66=.)
recode PRCCS3 (-99 -88 -66=.)
recode PRCCS4 (-99 -88 -66=.)
recode PRCCS5 (-99 -88 -66=.)
recode PRCCS6 (-99 -88 -66=.)
recode PRCCS7 (-99 -88 -66=.)
recode PRCCS8 (-99 -88 -66=.)
recode PRCCS9 (-99 -88 -66=.)
recode PRCCS10 (-99 -88 -66=.)
recode PRCCS11 (-99 -88 -66=.)
recode PRCCS12 (-99 -88 -66=.)
recode PRCCS13 (-99 -88 -66=.)
recode PRCCS14 (-99 -88 -66=.)
recode PRCCS15 (-99 -88 -66=.)
recode PRDAY1 (-99 -88 -66=.)
recode PRDAY2 (-99 -88 -66=.)
recode PRDAY3 (-99 -88 -66=.)
recode PRDAY4 (-99 -88 -66=.)
recode PRDAY5 (-99 -88 -66=.)
recode PRDAY6 (-99 -88 -66=.)
recode PRDAY7 (-99 -88 -66=.)
recode PRDAY8 (-99 -88 -66=.)
recode PRDAY9 (-99 -88 -66=.)
recode PRDAY10 (-99 -88 -66=.)
recode PRDAY11 (-99 -88 -66=.)
recode PRDAY12 (-99 -88 -66=.)
recode PRDAY13 (-99 -88 -66=.)
recode PRDAY14 (-99 -88 -66=.)
recode PRDAY15 (-99 -88 -66=.)
recode RACE (-9 -8 -6 -5=.)
recode SERVICELINE (-99 -88 -66=.)
recode TOTCHG (-999999999 -888888888 -666666666=.)
recode TRAN_IN (-9 -8 -6 -5=.)
recode TRAN_OUT (-9 -8 -6 -5=.)
recode YEAR (-999 -888 -666=.)
recode ZIPINC_QRTL (-9 -8 -6 -5=.)

save "C:\Users\mjafaribidgoli\Desktop\HCUP\HCUP_NIS_201 4\NIS_2014_Core.dta", replace