## To find continuity in enrollment of a patient

Solved
Occasional Contributor
Posts: 7

# To find continuity in enrollment of a patient

[ Edited ]

To find zero interval continuity..

Accepted Solutions
Solution
‎09-03-2016 05:54 AM
Posts: 5,535

## Re: To find continuity in enrollment of a patient

I interpreted your date interval requirement as continuous enrolment for the twelve months prior the index month, for the index month and for the eleven months after the index month.

``````data enrolment;
set sasforum.annual_cut;
array memday{12};
indexMonth = intnx("MONTH", index_dt, 0);
do i = 1 to 12;
month = mdy(i, 1, year);
days = memday{i};
if -12 <= intck("MONTH", indexMonth, month) <= 11 then output;
end;
format month indexMonth yymm.;
keep enrolId indexMonth month days;
run;

proc sql;
create table continuous as
select enrolId, indexMonth
from enrolment
group by enrolId, indexMonth
having sum(days) >= 2*365;
quit;``````
PG

All Replies
Solution
‎09-03-2016 05:54 AM
Posts: 5,535

## Re: To find continuity in enrollment of a patient

I interpreted your date interval requirement as continuous enrolment for the twelve months prior the index month, for the index month and for the eleven months after the index month.

``````data enrolment;
set sasforum.annual_cut;
array memday{12};
indexMonth = intnx("MONTH", index_dt, 0);
do i = 1 to 12;
month = mdy(i, 1, year);
days = memday{i};
if -12 <= intck("MONTH", indexMonth, month) <= 11 then output;
end;
format month indexMonth yymm.;
keep enrolId indexMonth month days;
run;

proc sql;
create table continuous as
select enrolId, indexMonth
from enrolment
group by enrolId, indexMonth
having sum(days) >= 2*365;
quit;``````
PG
Occasional Contributor
Posts: 7

## Re: To find continuity in enrollment of a patient

[ Edited ]

To find zero interval continuity.. 02

Occasional Contributor
Posts: 11

Thanks PGStats..

Posts: 5,535

## Re: To find continuity in enrollment of a patient

It is simpler to change the approach slightly because there can be anywhere between 365+365+28 and 365+366+31 days in 25 consecutive months. The new approach is: 1) keep only complete months within the desired range, then 2) select ranges that include exactly 25 consecutive months.

``````data enrolment;
set sasforum.annual_cut;
array memday{12};
indexMonth = intnx("MONTH", index_dt, 0);
do i = 1 to 12;
month = mdy(i, 1, year);
days = memday{i};
if -12 <= intck("MONTH", indexMonth, month) <= 12 and
days = intck("DAY", month, intnx("MONTH", month, 1))then output;
end;
format month indexMonth yymm.;
keep enrolId indexMonth month;
run;

proc sql;
create table continuous as
select enrolId, indexMonth
from enrolment
group by enrolId, indexMonth
having count(month) = 25;
quit;
``````
PG
Super User
Posts: 10,784

## Re: To find continuity in enrollment of a patient

```PG,
Why not use RANGE() in your original code?

proc sql;
create table continuous as
select enrolId, indexMonth,  range(indexMonth) as range
from enrolment
group by enrolId, indexMonth
having sum(days) >= 2*365;
quit;

```
Posts: 5,535

## Re: To find continuity in enrollment of a patient

@Ksharp, I guess you mean RANGE(month)? I can't see how that would help.

See new version of the code for a simpler solution that can also accomodate any number of consecutive months.

PG
Super User
Posts: 10,784

## Re: To find continuity in enrollment of a patient

```OK. Test it on your own. I have no time to check it.

data key;
set annual_cut;
array x{*} memday1-memday12;
do i=1 to dim(x);
monyy=put(mdy(i,1,year),monyy7.);
value=x{i};
output;
end;
keep enrolid monyy value;
run;

data want;
if _n_=1 then do;
if 0 then set key;
declare hash h(dataset:'key',hashexp:20);
h.definekey('enrolid','monyy');
h.definedata('value');
h.definedone();
end;
set annual_cut;
pre_sum=0;
do i=-11 to 0;
monyy=put(intnx('month',index_dt,i),monyy7.);
if h.find()=0 then pre_sum+value;
end;

post_sum=0;
do j=0 to 11;
monyy=put(intnx('month',index_dt,j),monyy7.);
if h.find()=0 then post_sum+value;
end;

if pre_sum ge 365 and post_sum ge 365 then output;

drop i j monyy value;
run;

```
Occasional Contributor
Posts: 7

## Re: To find continuity in enrollment of a patient

Thank you Ksharp, for your time and efforts..

Occasional Contributor
Posts: 11

## Re: To find continuity in enrollment of a patient

Thanks Ksharp..

Occasional Contributor
Posts: 7

## Re: To find continuity in enrollment of a patient

Hi Ksharp,

The codes that you have provided to me (which are aliter for below codes provided by PGStats) are giving distinct number of observations. Can you please look into it.

1. Even after changing the pre_sum do interval to: <do i =-12 to -1> and,

2. I am sure that there are no duplicates in final dataset that I get after running PGStats codes and your codes.

``````data enrolment;
set sasforum.annual_cut;
array memday{12};
indexMonth = intnx("MONTH", index_dt, 0);
do i = 1 to 12;
month = mdy(i, 1, year);
days = memday{i};
if -12 <= intck("MONTH", indexMonth, month) <= 11 then output;
end;
format month indexMonth yymm.;
keep enrolId indexMonth month days;
run;

proc sql;
create table continuous as
select enrolId, indexMonth
from enrolment
group by enrolId, indexMonth
having sum(days) >= 2*365;
quit;``````

Thanks!

Super User
Posts: 10,784

## Re: To find continuity in enrollment of a patient

```That is because I counted
month=-11 to 0
AND
month=0 to 11

Notice: I count month=0 twice.

PG only count month=0 once .

```
Occasional Contributor
Posts: 7

## Re: To find continuity in enrollment of a patient

[ Edited ]

Sorry Ksharp, but in last message I replied that I have changed the first do loop for pre_sum to -12 to -1 and I have checked that there are no duplicates in final datasets of yours i.e. "want" and final dataset of PG i.e. "continuous" and as I last remember yours' codes were giving less number of observations as compared to PG's.

Thanks!!

Super User
Posts: 10,784

## Re: To find continuity in enrollment of a patient

```I am not following the message after that.
My code would not take care of duplicated value,since it is monthly (1-12) data.

if you want that change:
i =-11 to 0
-->
i=-12 to -1

My code will give you the exact number as the number of original dataset.

If you have some data like this, mine is different with PG.
id   date
1   01jan2010
1   10feb2010
1   01jan2010
1   01jan2010

```
☑ This topic is solved.