I have a table of data that lists a patient's name, Medical record Number, Admission Date, Laboratory Haemoglobin Value, and the time the test was taken.
I want to limit the resuilts in the query to show only the patient's first Laboratory HB (haemoglobin) value, but I cannot get the query to work. It keeps outputting very strange results and I cannot figure out how to do it.
There are 1600 records within this table for approx. 192 patients. Any ideas?

Anne there has been many discussions on the forum regarding the use of first and last but the experts conclusion is don't use them. I wont go into it now a search on First and Pat Hartman as user will point you at the info.

Now your problem, I think that you will need 3 queries
1 Groupby the first 2 fields of the current query and Min on Date this gives the earliest date
2 join this to the 2nd table and min on time to get earliest time
3 join this back to table on time + other fields as needed to then get the HB level. Run this query

Brian

Cheers Brian,

I did what you suggested - it is a logical answer when you see the end result - just couldn't see the wood for the trees!

First time using this forum - delighted with the result!

Anne