[NEWBIE] Interpretation of blastp results

[Ichisen]

I'm extremely new to this and I apologize if this question seems naive. I created a database for virulence factors and did BLASTP.

I got the the following values:

qaccver saccver pident length mismatch gapopen qstart qend sstart send evalue bitscore

However, according to my reference journal, I need "slen" or length of matching sequence and "qlen" or length of query sequence to be used in a formula to identify the homologous protein. The formula is:
Ha = pident x slen/qlen

Is "slen/qlen" equivalent to "length" already?

or can I just use evalue and pident to identify the best match? Can you recommend a protocol for this?

Thank you!