searching for age within range

[axescot78]

I have 2 datasets that look like the this:

data match_data;
input uniq_ID_A $ Sex $ Race $ Dx_Age 3. uniq_ID_B $ Sex $ Race $ Age_Begin 3. Age_End 3.;
datalines;
5018 F B 35 1013 F B 36 39
3127 M H 25 2996 M H 26 37
5571 M W 32 1290 M W 33 42
2058 F W 35 4130 F W 38 45
1785 F B 37 3053 F B 38 41
1278 M W 49 1686 M W 49 53
2446 M W 33 3716 M W 35 44
3067 M H 39 5010 M H 40 52
3146 M B 32 5299 M B 32 45
3429 M B 30 5243 M B 30 35
5771 M A 30 4027 M A 31 42
;


data pt_data;
input uniq_ID_B $ DOB:MMDDYY10. Visit_Date:MMDDYY10. Visit_Reason_Code $ Other_Demographic_Data $ ;
format DOB MMDDYY10. Visit_Date MMDDYY10.;
datalines;
2996 9/25/1990 9/24/2016 6 xzxz
2996 9/25/1990 11/15/2016 6 xzxz
2996 9/25/1990 12/5/2016 4 xzxz
5299 12/1/1984 12/1/2016 2 xzxz
5299 12/1/1984 12/27/2016 5 xzxz
5299 12/1/1984 2/21/2017 5 xzxz
5299 12/1/1984 3/14/2017 1 xzxz
5299 12/1/1984 4/26/2017 6 xzxz
5299 12/1/1984 5/21/2017 5 xzxz
4027 6/3/1990 6/2/2021 1 xzxz
4027 6/3/1990 7/5/2021 4 xzxz
;

The first has a study population matched with a control population. Due to size constraints, I couldn't pull all the data that I wanted from the control population. Now I would like to go back to the second data set and pull the remaining data. However, I am only interested in the entry whose age is closest to the match from the first data set. For example, for 2996 I am interested in the entry whose age is closest to 25 (the age of his match). For 5299, I am interested in the entry when he was 32 (the age of his match). Same for 4027, 30, the age of his match.

Any advice how to code this?

[KachiM]

"Same for 4027, 31, the age of his match."

Is it not 30?

[axescot78]

oh yea, 30... edited

[andreas_lds]

Please show exactly which obs to pull from the second dataset and explain what what should happen, if two obs in the second dataset have the same age.

[axescot78]

Good catch! So this is fake data that I created for this post. The actual data has ages to 2 decimal places so there won't be any observations with the same age.

[axescot78 · Accepted solution]

I ended up calculating the age difference, sorting by ID and age difference smallest to largest, and then selecting the first ID entry. Worked well.