Table 2.

Reasons for exclusion of practices initially selected from the telephone directory

Reason for exclusion	Total number of practices excluded n = 61)	Percent of excluded practices (61 = 100%))
Service/Treatment in question not offered, e.g. pulmonary function test	21	34.4
Practice closed for vacation for more than 1 week after the initial call (as indicated on the answering machine)	6	9.8
Practice not attainable after three attempts (excluding "line busy")	4	6.6
Practice offering only open consultation hours	10	16,4
Exclusive service for private insurees	13	21.3
Practice no longer in service	7	11.5