BOOKS OF RtfiDIfGS - PAHO/WHO

O.667(A/(wL))I
where A is the area of the servce area in square miles and L is the
number of physician locatio;s in ihe service auea. Expected distaníce
was etimated for each revice area allowing for the different types of
practice--olo, partnerhip, aid group [22]. A convernion factor, estimated
to be 13 [22]. was employed o convert expected distance into
expected road distance.
Lacking informatin specific to Indiana, we anumed a simple
linear relationship betnen distance and demand rate. Using data
obtained from a sudy by Kane [2]J, we estimated the sope of this
line aud ausumed that the rclatiozhip observed for rural Kentucky
would also hold for rural Indiana becae of similar topography. This
set of assumptiocs led to the following equation for ,eographic accessibility
in a service ara:
4CCESS, = 100 - 2.5D
where ACCESS i the geopphic acceibility in tervice area j, expresed
as pe ntge, and DJ is tbe pectd~ road distance to physidcum
in lerv ~ j. The lMerpreta~on of the ucembility calculatian
b ti 100-ACCESI b tbe percentage of potential demand
tha doaes n bcoe exprced demand becaue of distance to a
physidan.
3. Com>ap #e ],ct ofl c omic St tusw on Expresucd tcmannd.
A ponaran :J Ph. potental demand kfr primary medical care is de-
Bflead by hc moaat ourn of obulning r The ecoaomic fecai.
blit7 of ob~ning cue b defined oa the br of restricted activity
dap par ymr, mui tr daa uad p~ccdurcs of Weds and Greenlick
[24]. As down la Table 8, peraina in low.inmme famillie ned more
mM~i l am thih pan In amll~ with bigher jcmnas It b as.
anme d (mnd tbis maumptou ba borne out by the data in Tabl 3) that
the hgber a fuity LaoCe. the arg the percentage of needa (po.
tental d and) ezxpea ua visita to physician. It is further assumed
TaS 8 Ceompma f _ dmaic Pembili Index
ldana iicv
o / , P restzLCted ~rlbilty
NED FOIL
PRaIMLRY CARE
PHYSICIANS