Objective: To assess factors related to consensus among community phys
icians regarding appropriate screening intervals for eight cancer scre
ening procedures for which guidelines have been published. Design: Int
erviews were conducted with a national random sample of 3436 physician
s in family practice, internal medicine, general surgery, and gynecolo
gy by mail or telephone or both. The overall response rate was 67%. Me
asurements: Consensus by specialization and by physician and practice
characteristics on the appropriate screening intervals for early detec
tion of cancers of the breast, cervix, colon and rectum, and lung for
asymptomatic adults at normal risk. ii Results: More than 60% of the p
hysicians surveyed agreed on the length of the screening intervals for
six of eight procedures. Consensus most closely followed American Can
cer Society- and National Cancer Institute-recommended screening inter
vals for all procedures except chest roentgenogram Acceptance of scree
ning intervals was not related to the extent of agreement among publis
hed guidelines. Surgeons tended to favor more aggressive screening tha
n family physicians and internists; gynecologists most consistently fa
vored aggressive screening for cancers occurring in women. Older physi
cians and those in solo practice tended to favor outmoded procedures s
uch as routine chest roentgenograms and to be more conservative about
screening intervals. Conclusions: Physicians stated that they follow t
he American Cancer Society and National Cancer Institute guidelines fo
r cancer screening more than the guidelines published by their own spe
cialty societies, but they also reported procedures not recommended in
any guidelines. These findings suggest that changing physician screen
ing practices will be difficult.