Dear all,

I am using Stata 16, on mac and have provided a sample of my dataset using dataex.

I am having a problem. My dataset is based on a longitudinal survey so the same participants were tracked from 1997-2009. The participants ID number is given the variable name PUBID_1997.The participants who dropped out of particular years is indicated by -5 for the age_months. For example, the second participant that was tracked from 1997-2009 has -5 for age_months since they dropped out of the study in 2006 and 2007. The problem is when I use the Stata code drop if age_months==-5 for example it doesn't not get rid of the second participant entirely but only deletes the second participant's rows for the years 2006 and 2007. Is there a way to write a Stata code that deletes a participant entirely if age_months==-5? So for example, since participant 2 dropped out of the study I would like to remove them completely from my analysis.

Here is a sample of my dataset using dataex

nput int(PUBID_1997 year) byte(sex_1997 race_1997) int age_months byte(ever_smoked ever_alcohol ever_marijuana)

1 1997 2 4 190 1 1 0

1 1998 2 4 206 -4 -4 -4

1 1999 2 4 219 -4 -4 -4

1 2000 2 4 231 -4 -4 -4

1 2001 2 4 243 . . .

1 2002 2 4 256 . . -4

1 2003 2 4 266 . . .

1 2004 2 4 279 -4 -4 -4

1 2005 2 4 290 -4 -4 -4

1 2006 2 4 302 . . .

1 2007 2 4 313 . . .

1 2008 2 4 325 . . .

1 2009 2 4 337 . . .

2 1997 1 2 178 0 0 0

2 1998 1 2 196 -4 -4 -4

2 1999 1 2 209 -4 -4 -4

2 2000 1 2 221 -4 -4 -4

2 2001 1 2 232 . . .

2 2002 1 2 245 . . -4

2 2003 1 2 256 . . .

2 2004 1 2 268 -4 -4 -4

2 2005 1 2 284 -4 -4 -4

2 2006 1 2 -5 . . .

2 2007 1 2 -5 . . .

2 2008 1 2 318 . . .

2 2009 1 2 330 . . .

3 1997 2 2 163 0 1 0

3 1998 2 2 182 -4 -4 -4

3 1999 2 2 197 -4 -4 -4

3 2000 2 2 210 -4 -4 -4

3 2001 2 2 222 . . .

3 2002 2 2 232 . . -4

3 2003 2 2 249 . . .

3 2004 2 2 255 -4 -4 -4

3 2005 2 2 -5 -5 -5 -5

3 2006 2 2 -5 . . .

3 2007 2 2 -5 . . .

3 2008 2 2 -5 . . .

3 2009 2 2 317 . . .

4 1997 2 2 192 0 1 0

4 1998 2 2 213 -4 -4 -4

4 1999 2 2 228 -4 -4 -4

4 2000 2 2 238 -4 -4 -4

4 2001 2 2 251 . . .

4 2002 2 2 262 . . -4

4 2003 2 2 276 . . .

4 2004 2 2 287 -4 -4 -4

4 2005 2 2 297 -4 -4 -4

4 2006 2 2 309 . . .

4 2007 2 2 320 . . .

4 2008 2 2 336 . . .

4 2009 2 2 344 . . .

5 1997 1 2 186 1 1 1

5 1998 1 2 194 -4 -4 -4

5 1999 1 2 205 -4 -4 -4

5 2000 1 2 218 -4 -4 -4

5 2001 1 2 234 . . .

5 2002 1 2 243 . . -4

5 2003 1 2 255 . . .

5 2004 1 2 266 -4 -4 -4

5 2005 1 2 277 -4 -4 -4

5 2006 1 2 289 . . .

5 2007 1 2 300 . . .

5 2008 1 2 312 . . .

5 2009 1 2 323 . . .

6 1997 2 2 188 0 0 0

6 1998 2 2 202 -4 -4 -4

6 1999 2 2 215 -4 -4 -4

6 2000 2 2 229 -4 -4 -4

6 2001 2 2 242 . . .

6 2002 2 2 251 . . -4

6 2003 2 2 266 . . .

6 2004 2 2 278 -4 -4 -4

6 2005 2 2 290 -4 -4 -4

6 2006 2 2 302 . . .

6 2007 2 2 310 . . .

6 2008 2 2 323 . . .

6 2009 2 2 334 . . .

7 1997 1 2 173 0 0 0

7 1998 1 2 187 -4 -4 -4

7 1999 1 2 200 -4 -4 -4

7 2000 1 2 214 -4 -4 -4

7 2001 1 2 224 . . .

7 2002 1 2 237 . . -4

7 2003 1 2 -5 . . .

7 2004 1 2 -5 -5 -5 -5

7 2005 1 2 275 -4 -4 -4

7 2006 1 2 283 . . .

7 2007 1 2 -5 . . .

7 2008 1 2 -5 . . .

7 2009 1 2 319 . . .

8 1997 2 4 202 0 0 0

8 1998 2 4 210 -4 -4 -4

8 1999 2 4 221 -4 -4 -4

8 2000 2 4 234 -4 -4 -4

8 2001 2 4 246 . . .

8 2002 2 4 258 . . -4

8 2003 2 4 273 . . .

8 2004 2 4 282 -4 -4 -4

8 2005 2 4 295 -4 -4 -4

end

label values PUBID_1997 vlR0000100

label def vlR0000100 1 "1 TO 999", modify

label values sex_1997 vlR0536300

label def vlR0536300 1 "Male", modify

label def vlR0536300 2 "Female", modify

label values race_1997 vlR1482600

label def vlR1482600 2 "Hispanic", modify

label def vlR1482600 4 "Non-Black / Non-Hispanic", modify


Thank you in advance for your help

Jason Browen