Hi Reeza, Thank you for still being with me. Hope you will be with me until I am able to solve this problem.  So I guess this is what I want 03/13/2018  02/27/1931  1  N mmc 200 03/13/2018  02/27/1931  1  N mmc 200 01/19/2018 10/06/1934  mmc  300 02/26/2018 10/21/1944  10  P 02/13/2018  03/06/1978  1   N mmc  300 02/13/2018  03/06/1978  1   N mmc  300 01/26/2018  04/14/1949   1  N mmc 200 02/06/2018  04/14/1949  1  P mmc  300 I want everything for the lab data with added info from clinic if available.   Reeza, May be this might give you an idea better.   Lab Clinic A A B B C C C   D D D D E E F F G G G   H MISSING I I J J   J   J In the table above, person A & B visit clinic and get tested so I have info in both data sets. Person C visited clinic once, but got two tests done. Person D visited clinic twice, tested twice. Person E & F visited clinic and got tested. Person G visited clinic once and tested twice or had two different tests done. Person H is not in clinic data set. Person J visited clinic four times but only had two tests done. This is the pattern of the two datasets I am trying to merge. Your help will be appreciated. ... View more

Hi Reeza, I have 1109 visit date data in set 1 (clinic visit data)and I have 1704 visit date data in another set Lab test data). I have 899 unique patient in set 1 and 932 in set 2. Don't know how to say. So I have multiple in data1 and multiple in data2 in some case but in some case I have 1 in set one ands multiple in another case. Same person can have multiple tests on the same day and same day multiples patients get tested. I am trying to find the number of tests and test results. ... View more

As I mentioned earlier, these two data sets (lab and clinic) have two common variables and they are repeated in both datasets. Same individual may have several test at the same date and result of different can be different. And on the same date many individual get tested. All I want to know is number and type of tests done and their results. ... View more

  FROM THIS : First data set contents; 02/13/2018  03/06/1978  1   N 02/13/2018  03/06/1978  1   N   Second data set contains: 02/13/2018  03/06/1978  mmc  300 02/13/2018  03/06/1978  mmc  300   THIS IS WHAT I WANT 02/13/2018  03/06/1978  1   N mmc  300 02/13/2018  03/06/1978  1   N mmc  300 ... View more

Reeza, I know I am not being very explicit about what I have and what I want. Let me try to explain as clear as I can. I did ORDER=FREQ and NLEVELS To identify duplicates, and this is what I found out. I have two datasets. This data set has other variables for example test type and test result. Datasets A (lab data) has 932 unique DOB, of these Of 932 DOB: 443 DOB IS REPEATED TWICE 94 IS REPEATED THREE TIMES 23 REPEATED FOURTIMES 9 REPEATED 5 TIMES 4 REPEATED SIX TIMES 2 REPEATED 7 TIMES This data set also has other variables for example test type and test result. Data set B has 899 (clinic data) DOB, Of 899 DOB: 127 is repeated twice 37 is repeated three times 3 is repeated four times. And both dataset has visit date which is repeated as many as 39 times meaning that date that many test were conducted. So what I am trying to get is find out number and type of tests done, and number of test results negative or positive by merging these two data set. your help will be really appreciated. ... View more

HI Reeza, So then I should porbably use Visit id and  DOB variable.  One of my friends said he did it by converting the dates to sequential serial numbers and then concatonated those two numbers into one 10 digit number, and matched on that.  He did it in Epiinfo, there might be a way to do what he did in SAS, but I don't know. It would be great if you can help with that.  Thank you so much. ... View more

Hello, than you for your response. I did it again data LAB; input visit_dt date9. @12 Bdate date9. @22 Test $ @24 testresult $; format Bdate mmddyy10. visit_dt mmddyy10. ; cards;   13mar2018 27feb1931 gc n 26feb2018 21oct1944 gc n 13feb2018 06mar1948 gc p 13feb2018 06mar1948 gc n 26jan2018 14apr1949 gc p 02feb2018 14apr1949 gc n ; RUN; proc print data=lab; run; proc sort data=lab; by visit_dt bdate; run; data CLINIC; input visit_dt date9. @12 Bdate date9. @22 clinic $ diag @26 ; format Bdate mmddyy10. visit_dt mmddyy10. ; cards;   13mar2018 27feb1931 mmc 200 19jan2018 06oct1934 mmc 300 26feb2018 21oct1944 mmc 300 26jan2018 03jun1978 mmc 300 13feb2018 06mar1948 mmc 200 26jan2018 14apr1949 mmc 300 02feb2018 14apr1949 mmc 300 ; RUN; proc print data=clinic; run; proc sort data=clinic; by visit_dt bdate; run; data labcli; merge lab clinic; by visit_dt bdate; run;  it wirked perfectly here but in real datasets I am not sure if it merged correctly because when I did frequency analysis for test the result was not accurate and te log says; merge statement has multiple repeat values in by variable etc....Please help:(   ... View more