I write regarding the number of decimal places (significant figures) to
which we should report results:
In concept I agree with the idea that the number of significant figures
should reflect the precision of the measurement. My problem with this is
that this varies widely with the numerical result. Taking HDL as an
example: at a value of 0.5 mmol/L, +/- 0.1 mmol/L is +/- 20% (hopefully our
precision is better than this) and +/- 0.01 is 2% (a pretty good HDL
assay!). At an HDL of 2.0 mmol/L, +/- 0.1 is 5% and +/- 0.01 mmol/L is 0.5%
(better than most of our assays). (note that these percentages are not the
same as assay CVs).
In summary the number of significant figures (on either side of the decimal
place) can only be a very approximate reflection of anything!
Regards,
Graham
Graham Jones
Staff Specialist in Chemical Pathology
St Vincent's Hospital, Sydney
Victoria St, Darlinghurst, 2010
NSW, Australia
Ph: (02) 8382-2170 Fax (02) 8382-2489
[log in to unmask]
**********************************************************************
This email and any files transmitted with it are confidential and
intended solely for the use of the individual or entity to whom they
are addressed. If you have received this email in error please notify
the system manager.
This footnote also confirms that this email message has been
virus scanned and although no viruses were detected by the system,
St Vincent's Hospital accepts no liability for any consequential
damage resulting from email containing any computer viruses.
**********************************************************************
------ACB discussion List Information--------
This is an open discussion list for the academic and clinical
community working in clinical biochemistry.
Please note, archived messages are public and can be viewed
via the internet. Views expressed are those of the individual and
they are responsible for all message content.
ACB Web Site
http://www.acb.org.uk
List Archives
http://www.jiscmail.ac.uk/lists/ACB-CLIN-CHEM-GEN.html
List Instructions (How to leave etc.)
http://www.jiscmail.ac.uk/
|