Leprosy
mailing list – September 8th, 2005
Ccn: all.
Ref.:
“discussion
document on monitoring of epidemiological trends of leprosy and
validation of data”.
From: W
v Brakel, Amsterdam, The Netherlands.
Dear
Salvatore,
I
would like to endorse the arguments put forward by Paul Saunderson (LML Sep. 6th, 2005) on use of
indicators for monitoring of epidemiological trends. I want to add two
points.
1.
Incidence rates are commonly expressed per 100,000 population.
Following the same practice for leprosy would therefore make good
sense.
2.
Regarding WHO disability grading, we have discussed the pros and cons
of this system in several published papers. I fully agree with Dr.
Saunderson that the grading is by no means ideal, but that its chief
strength lies in its widespread use. The utility of the data can be
further improved by calculating the EHF score (Eyes, Hands, Feet score -
the sum of the six individual disability grades) as indicator of
severity of impairment, instead of using only the maximum grade (van
Brakel et al., Lep Rev 1999; Saunderson et al., Lep Rev 2000; Meima et
al., Lep Rev 2001). The EHF score then can be used to calculate
simple cohort-based indicators, such as 'the proportion whose
impairment improved' or 'the proportion who impairment deteriorated'
between diagnosis and release from treatment. The EHF score is still
not as sensitive to change as the Impairment Summary Form, but the
latter is too sophisticated for most (integrated) leprosy control
programmes.
The
WHO disability grading (but maximum grade and EHF score) has been
shown to be very reliable, provided training is given and standardised
operational definitions are used (Brandsma et al., Lep Rev 2004 and
Nienhuis et al., Lep Rev 2004). A proposal for such definitions has
been published (Brandsma & van Brakel, Lep Rev 2003). If these
were implemented widely, the reliability of the WHO grading system
could be further improved.
With
best wishes,
