topic counting total number of drugs used in SAS Programming

counting total number of drugs used

lone0708 — Sun, 17 Apr 2022 07:28:37 GMT

Hello all,

I hope you can help me.

I have a dataset containing information about prescriptions for drugs filled for an individual. I have 4 types of drugs which can be prescribed several times. Some individuals uses more than one drug and I

1. need to count how many different drugs the individual uses.

2. need to count how many different drugs the individual uses in one month

3. how long time is the total drug use (in days)

Data have:

ID date_of_prescription Drug type

1 01012018 drug 1

1 02012018 drug 2

1 03042018 drug 1

2 04052017 drug 1

2 01062017 drug 3

3 10122014 drug 3

Output want:

Number of drugs used Individuals

1 X

2 X

3 X

4 X

2. The same as 1. but within one month

Number of drugs used Individuals

1 X

2 X

3 X

4 X

3. mean, median p25, p75

Re: counting total number of drugs used

HB — Mon, 18 Apr 2022 22:12:36 GMT

with data like

data have;
  input id script_date:mmddyy10. drug:$1.;
  format script_date mmddyy10.;
  datalines;
1 01012018 A
1 02012018 B
1 02022018 C
1 03042018 A
2 04052017 A
2 01062017 C
3 10122014 C
4 10122014 A
4 10132014 B
4 10142014 C
;
run;

One approach might be

*how many different drugs an individual uses;
proc sql;
	select id, count(distinct(drug)) as 'num drugs used'n
	from have
	group by id;
quit;


*how many different drugs an individual uses by month;
proc sql;
	select distinct month, year, 
	id, drugcount as 'drug count'n
	from 
	(
	select month(script_date) as month, year(script_date) as year, 
	id as id, count(distinct(drug)) as drugcount
	from have
	group by month(script_date), year(script_date), id
	)
	order by 2 asc, 1 asc, 3;
quit; 

* drug use time period in days;
* start time is assumed to be prescription time;
* stop time is undefined and assumed as today;
proc sql;
	select id, script_date as 'drug start date'n, 
	drug, today() - script_date as 'days of usage'n
	from have;
quit;

which provides out of

id	num drugs used
1	3
2	2
3	1
4	3

month	year	id	drug count
10	2014	3	1
10	2014	4	3
1	2017	2	1
4	2017	2	1
1	2018	1	1
2	2018	1	2
3	2018	1	1

id	drug start date	drug	days of usage
1	1/1/2018	A	1568
1	2/1/2018	B	1537
1	2/2/2018	C	1536
1	3/4/2018	A	1506
2	4/5/2017	A	1839
2	1/6/2017	C	1928
3	10/12/2014	C	2745
4	10/12/2014	A	2745
4	10/13/2014	B	2744
4	10/14/2014	C	2743

Re: counting total number of drugs used

andreas_lds — Tue, 19 Apr 2022 07:10:29 GMT

Please post the expected results of all tasks you have to solve and show what you have tried so far.

EDIT

You should also explain how a duration in days should be calculated without having an end-date. You said:

Some individuals uses more than one drug

So using the prescription date of drug b as an end date for drug a seems wrong.