SQL & PL/SQL

Hello:

I have a query where I would like to get total counts. The result of the query should look like this:

org clinician name yes no na total
1 123 brown 5 2 0 7
2 345 gray 1 1 1 3
etc....

When I run my query, I receive the following error message:
ORA-01722 - Invalid Number

The sub-query which I'm using to do my counts is based on a field named cmf_flag which is a varchar though it contains a numeric value. Here is the query where I'm going through the decode and to_number process:

select org_key,
           clinician_key, 
           clin_name,
           yes,
           no,
           na,
            total

from 
  
      (select 
         clinician_key, 
	       clin_name, 
         org_key,
        count(decode(to_number(pi.cmf_flag),1,1)) YES,
         count(decode(to_number(pi.cmf_flag),2,1)) NO,
         count(decode(to_number(pi.cmf_flag),3,1)) NA,
         count(pi.rowid) as TOTAL
    
from v_patient_info pi

where org_key = &orgkey
       and program_key = &program_key

group by org_key, clinician_key, clin_name
)

order by org_key asc, clin_name asc;

Can someone help me?

Thanks