如何在 sas 中使用 proc sql 查找丢失的案例？

Question

我想在 sas 中使用 proc sql 来识别案例或记录​​是否缺少某些信息。我有两个数据集。一个是整个数据收集的记录，显示访问期间收集了哪些表格。第二个是在访问期间应该收集哪些表格的规范。我尝试了很多选项，包括使用not in 的数据步骤和sql 代码，但无济于事......

示例数据如下

---

*****  dataset crf is a listing of all forms that have been filled out at each visit ;
*****  cid is an identifier for a study center  ;
*****  pid is an identifier for a participant  ;

data crf;
  input visit cid pid form ;
cards;
1 10 101 10
1 10 101 11
1 10 101 12
1 10 102 10
1 10 102 11
2 10 101 11
2 10 101 13
2 10 102 11
2 10 102 12
2 10 102 13
;
run;


*****  dataset crfrule is a listing of all forms that should be filled out at each visit  ;
*****  so, visit 1 needs to have forms 10, 11, and 12 filled out  ;
*****  likewise, visit 2 needs to have forms 11 - 14 filled out  ;

data crfrule;
  input visit form ;
cards;
1 10
1 11
1 12
2 11
2 12
2 13
2 14
;
run;


*****  We can see from the two tables that participant 101 has a complete set of records for visit 1 ;
*****  However, participant 102 is missing form 12 for visit 1 ;
*****  For visit 2, 101 is missing forms 12 and 14, whereas 102 is missing form 14  ;


*****  I want to be able to know which forms were **NOT**  filled out by each person at each visit (i.e., which forms are missing for each visit)  ;


*****  extracting unique cases from crf ;
proc sql;
  create table visit_rec as
    select distinct cid, pid, visit
      from crf;
quit;



*****  building the list of expected forms by visit number ;
proc sql;
  create table expected as 
    select  x.*,
            y.*

    from visit_rec as x right join crfrule as y
      on x.visit = y.visit

    order by visit, cid, pid, form;
quit;


*****  so now I have a list of which forms that **SHOULD** have been filled out by each person  ;

*****  now, I just need to know if they were filled out or not...  ;

---

我一直在尝试的策略是将expected 合并回crf 表中，并带有一些指示每次访问缺少哪些表单。

理想情况下，我想生成一个包含以下内容的表：visit、cid、pid、missing_form

非常感谢任何指导。

Answer 1

EXCEPT 会做你想做的事。我不一定知道这通常是最有效的解决方案（如果您在 SAS 中执行此操作，几乎可以肯定不是），但鉴于您到目前为止所做的，这确实有效：

create table want as
    select cid,pid,visit,form from expected
    except select cid,pid,visit,form from crf
;

请小心 EXCEPT - 它非常挑剔（请注意 select * 不起作用，因为您的表格的顺序不同）。

Answer 2

我建议使用嵌套查询，也可以分两步完成。这个呢：

proc sql;
   create table temp as
   select distinct c.*
        , (d.visit is null and d.form is null and d.pid is null) as missing_form 
   from (
      select distinct a.pid, b.* from
      crf a, crfrule b
      ) c 
   left join crf d
   on     c.pid = d.pid 
      and c.form = d.form 
      and c.visit = d.visit
   order by c.pid, c.visit, c.form
   ;
quit;

它为您提供了一个列表，其中包含 pid、表单、访问和一个布尔值的所有可能（即预期）组合，指示它是否存在。

Answer 3

您可以使用左连接并使用 where 子句过滤掉右表中缺少记录的记录。

 select 
  e.* 
 from
  expected e left join 
  crf c on
   e.visit = c.visit and 
   e.cid = c.cid and
   e.pid = c.pid and
   e.form = c.form
 where c.visit is missing
;