Dear R epidemiologists,

The package help for the above function states:

Arguments X A 2x2 matrix, with Gold Standard Class A and B in the columns
and Comparison Method A and B in the rows.
I understood this to mean the following:

                                   Gold standard
Comparison method         A (neg)     B (pos)
A  (neg)                          18             1
B   (pos)                          0              201

However, it gives the results backwards:

 sensSpec(t1)

 Simple Sensitivity and Specitivity Output

Input Matrix:
          ref
r1a        negative positive
  negative       18        1
  positive        0      201

The sample of sensitivity is: 100%

The sample of specificity is: 99.5%

but if you calculate the sensitivity and specificity by hand, sensitivity is
99.5 and specificity is 100%....


Many thanks,
Amy




-- 
Amy Mikhail
Program Manager, ACTc Afghanistan Malaria Project
London School of Hygiene & Tropical Medicine

****** NEW HPRO OFFICE ADDRESS
************************************************************************************************************************
HPRO Head Office, House number P860 (10th house on the right off Taimany
road), Street 10, Taimany, District 10, Kabul, Afghanistan
*********************************************************************************************************************************************************************

Email (Afg): amy.mikhail@googlemail.com
Email (UK): Amy.Mikhail@lshtm.ac.uk
Tel (Afg): +93 (0)706 126627
Tel (UK): +44 (0)781 4176107

	[[alternative HTML version deleted]]

