PRINCETON, NJ -- Most Americans say cancer screening tests today are done about the right amount of time (58%) or not frequently enough (31%). Americans have thus internalized the conventional wisdom about the benefits of cancer screening and early detection -- despite recent evidence that some cancer screening tests do more harm than good.
The value of cancer screening tests has been challenged in the medical literature in recent years. This is based on studies showing that the benefits of such tests, as measured by the ultimate goal of decreased cancer deaths, may not always outweigh the impact of false positives, repeated invasive tests, injurious procedures, and negative side effects of treatment. The U.S. Preventive Services Task Force's recommendations on lessened use of mammograms and PSA tests to screen for breast and prostate cancer, respectively, have generated substantial controversy in the medical community and in the general population.
Americans for many years have heard the traditional admonition that "early detection" of cancer is always beneficial for the patient, and the results of the current question suggest that this belief still holds in the minds of most. Few Americans (7%) believe that cancer tests are conducted too frequently.
Perception That Screenings Aren't Done Frequently Enough Decreases With Age
The perception that cancer screening tests are not conducted frequently enough declines with age, from 52% among 18- to 29-year-olds to 10% among those 65 and older. Older Americans are, however, no more likely than younger Americans to say screening tests are done too often; the differences by age are seen in the categories of "about the right amount" and "not often enough." Older Americans' higher level of belief that cancer screening tests are done with about the right amount of frequency could reflect the almost certain likelihood that this older group has been exposed more often to cancer screening tests than those who are younger.
Americans with college educations may be more likely than the less well educated to have read or heard news of the recent controversies about the efficacy of cancer screening, given the correlation between attention to news and education. Yet highly educated Americans are no more likely than others to say cancer screening tests are conducted too frequently.
Americans for the most part believe that cancer screening tests are done with about the right amount of frequency or not often enough, highlighting the attitudinal difficulty faced by the Preventive Services Task Force and other healthcare professionals who present evidence that cancer screening and early cancer detection is not always a good thing.
Previous Gallup research shows that 7 in 10 Americans usually feel confident in the accuracy of their doctor's medical advice, suggesting that attitudinal changes in the general population may need to come from the healthcare professionals Americans routinely come in contact with.
Results for this Gallup poll are based on telephone interviews conducted Nov. 3-6, 2011, with a random sample of 1,012 adults, aged 18 and older, living in the continental U.S., selected using random-digit-dial sampling.
For results based on the total sample of national adults, one can say with 95% confidence that the maximum margin of sampling error is ±4 percentage points.
Gallup surveyed 532 men and 480 women. For results based on men, one can say with 95% confidence that the maximum margin of sampling error is ±5 percentage points. For results based on women, one can say with 95% confidence that the maximum margin of sampling error is ±6 percentage points.
Interviews are conducted with respondents on landline telephones and cellular phones, with interviews conducted in Spanish for respondents who are primarily Spanish-speaking. Each sample includes a minimum quota of 400 cell phone respondents and 600 landline respondents per 1,000 national adults, with additional minimum quotas among landline respondents by region. Landline telephone numbers are chosen at random among listed telephone numbers. Cell phone numbers are selected using random-digit-dial methods. Landline respondents are chosen at random within each household on the basis of which member had the most recent birthday.
Samples are weighted by gender, age, race, Hispanic ethnicity, education, region, adults in the household, and phone status (cell phone only/landline only/both, cell phone mostly, and having an unlisted landline number). Demographic weighting targets are based on the March 2010 Current Population Survey figures for the aged 18 and older non-institutionalized population living in U.S. telephone households. All reported margins of sampling error include the computed design effects for weighting and sample design.
In addition to sampling error, question wording and practical difficulties in conducting surveys can introduce error or bias into the findings of public opinion polls.
For more details on Gallup's polling methodology, visit www.gallup.com.