Prevalence of Cancer Screening in Older, Racially Diverse Adults: Still Screening After All These Years

Background While a great deal is known about cancer screening behaviors and trends in young and middle-aged adults, little is known about screening behaviors in older adults from different racial backgrounds. Our goal was to establish prevalence estimates and correlates of cancer screening, including physician recommendation in older (≥75 years), racially diverse adults.

Methods Data were analyzed from the National Health Interview Survey—an annual, in-person, nationwide survey used to track health trends in US civilians. The analytic sample included 49 575 individuals, of whom 1697 were 75 to 79 years old and 2376 were 80 years or older. Screening behaviors were examined according to the US Preventive Services Task Force recommendations for breast, cervical, colorectal, and prostate cancer screening.

Results Among adults aged 75 to 79 years, the percentage screened for cancer was as follows: colorectal, 57%; breast, 62%; cervical, 53%; and prostate, 56%. Among those 80 years or older, rates of screening ranged from a low of 38% for cervical cancer to a high of 50% for breast cancer. Although unadjusted screening prevalence rates differed by race/ethnicity, these differences were accounted for by low education attainment in the multivariate logistic regression model. Physician recommendation for a specific test was the largest predictor of screening. Over 50% of men and women older than 75 years report that their physicians continue to recommend screening.

Conclusion A high percentage of older adults continue to be screened in the face of ambiguity of recommendations for this group.

While promotion of early detection of cancer through screening programs has led to a substantial decline in mortality and morbidity in the population,^1,2 the thrust of programs is to increase uptake and adherence to screening and to reducing minority disparities inscreening rates.³ Less attention has been given to assessing rates of screening in older, racially diverse adults, a population expected to grow exponentially over the next few decades.⁴ This is imperative because there is growing recognition that certain segments of the older population, mainly older healthy adults with good functional status, few comorbid conditions, and a life expectancy of more than 5 years may benefit from continued screening and, if needed, can tolerate cancer treatments.^5,6

Current US Preventive Services Task Force (USPSTF) screening guidelines suggest that there is insufficient evidence to evaluate the mortality benefits of screening men and women older than 75 years and advocate for individualized decisions in this group.⁷ The lack of clarity regarding screening guidelines for older adults is partly due to the paucity of data from screening and treatment trials that include older adults.⁸ As such, screening decisions for this group are often based on physicians' extrapolations from screening trials in younger adults, clinicians' subjective judgment of a person's health status, and patient preference.⁹

While a great deal is known about cancer screening behaviors and trends in young and middle-aged adults,^2,10-12 less is known about screening behaviors in older adults from different racial backgrounds. A study analyzing data from the 2006 Behavioral Risk Factor Surveillance System (BRFSS) found that 60% of men older than 76 years, without a history of prostate cancer, received a prostate-specific antigen (PSA) test in the past year,¹³ which is consistent with some studies examining PSA test use in older men,¹⁴ yet inconsistent with others that have found national rates of PSA test use to be 46% in older men.¹⁵ In regard to mammography, a study of women older than 65 years, without a history of cancer, who participated in the Health and Retirement Study, found 68% of the sample had received mammography screening in previous 2 years.¹⁶ Another study examining screening utilization in 87 736 older adults diagnosed as having advanced cancer from the linked Surveillance, Epidemiology, and End Results (SEER)/Medicare claims data set found a sizable proportion of older patients with terminal cancer continue to be screened with mammography (8.9%), Papanicolaou test (5.8%), and PSA test (15.0%), despite a median 5-year survival rate of less than 16%.¹⁷ What was not assessed in this study was whether continued screening was the result of physicians' recommendations or preferences of patients. Finally, a study examining older adults' attitudes and preferences for continued screening in later life found that 72% of adults 70 years or older reported that they would continue cancer screening throughout their lives, and almost half of those (43%) would continue despite their physician's recommendation against further screening.¹⁸ While these studies have contributed to our understanding of screening in older adults, the generalizability of these findings is limited for various reasons, including lack of racial diversity, examining rates of screening in data that are almost 10 years old, or including older adults (65-74 years) who still fall within guidelines for screening.

The goal of this study was to examine cancer screening practices and correlates of screening, including physician recommendations for screening tests in racially diverse older adults, given that this group is the fastest growing segment of the US population and the largest consumers of health care.¹⁹ We expected that a sizable proportion of adults older than 75 years would continue to be screened and that differences would exist by racial status that mirror well known differences in younger adult minority populations. We also anticipated that a substantial percentage of physicians would continue to recommend screening tests, despite guidelines that recommend against routine screening after age 75 years, and that these recommendations would vary by race/ethnicity.

Data were analyzed from the National Health Interview Survey (NHIS), an annual, in-person, nationwide survey of approximately 30 000 households that is used to track trends in illness and health status of noninstitutionalized US civilians.²⁰ Each survey year represents a different sample, and blacks and Hispanics are oversampled. To obtain a sample of adults from minority backgrounds with sufficient power for analyses we combined data from the surveys conducted in 2005 and 2008. The final response rate for the adult sample was 69.0% in 2005 and 62.6% in 2008.

Of the 31 428 sample adults surveyed in 2005, 2095 adults were excluded owing to self-reported diagnosis of cancer other than nonmelanoma skin cancer. The 2008 survey included 21 781 sampled adults, but 1539 reported a history of cancer and therefore were excluded from analyses. This resulted in an analytic sample of 49 575 (29 333 from 2005 and 20 242 from 2008), of whom 1697 were 75 to 79 years of age and 2376 were older than 80 years. Men and women who fell within USPSTF guidelines for screening (Table 1) were included in the analysis as a comparative group. Owing to concerns about confidentiality, the NHIS does not release exact ages for respondents older than 85 years. Hence, older respondents have their age truncated at 85 years.

Self-reported information included age, sex, race/ethnicity, education, family income (imputed for analyses), comorbidity (calculated as sum of 13 health conditions contained in the 2005 and 2008 NHIS), and physical limitations of any kind.

Screening behaviors of older adults were analyzed according to the USPSTF recommendations for breast, cervical, colorectal, and prostate cancer screening (Table 1).²¹ The USPSTF recommends against routine cervical cancer screening in women older than 65 years, and for other cancers, there is general agreement that screening decisions should be individualized based on life expectancy and patient preferences.

The NHIS asks participants “Within the past year, has a physician or other healthcare professional recommended that you have a particular screening test?” (ie, mammogram, Papanicolaou screen, fecal occult blood test, PSA test). Thus, we examined this question by age and race/ethnicity. This question was not asked in the survey for PSA testing in 2005.

To account for the complex sample design of the NHIS, including stratification, clustering, and multistage sampling, estimates were weighted to provide national estimates. Variance estimates for proportions and logistic regression model odds ratios (ORs) were calculated using SUDAAN statistical software (Research Triangle Institute; Research Triangle Park, North Carolina) to take into account the complexity of the survey design. Descriptive statistics, t tests, and χ² tests were used to examine differences between age, race/ethnicity, education, family income, comorbidities, and physical limitations between survey years (2005 and 2008). Despite statistically significant differences between survey years on age, income, and comorbidity, owing to the large sample size, the percentage differences were small (all <4%), suggesting no meaningful differentiation. Thus, the 2 data waves (2005 and 2008) were collapsed for analyses. To examine cancer screening rates of adults, weighted percentages, standard errors, and P values are presented by age group (screening guideline–specific ages for each test (75-79 years and ≥80 years) and race for each screening test. A multivariate logistic regression model is also presented for each test to indicate ORs of meeting guidelines by age group, race/ethnicity, education, family income, comorbidities, and physician recommendation. To further examine the percentage of physicians recommending specific screening tests by age and race/ethnicity, weighted percentages, standard errors, and P values are presented with t tests for differences between percentage of older age groups and guideline-specific ages for each racial group as well as within each age group.

Characteristics of the sample from each survey year are shown in Table 2. In the sample, 4073 participants were 75 years or older, providing sufficient sample size for estimating prevalence rates in this population. The mean (SE) age of the 4073 adults 75 years or older was 80.4 (0.07) years.

Table 3 shows the prevalence rates of screening for breast, cervical, colorectal, and prostate cancer by age group and race/ethnicity. Among women 75 to 79 years old and those 80 years or older, 62% and 50%, respectively, reported receiving a mammogram within the past 2 years. Receipt of mammogram in 50- to 74-year-old women was 74%. Similarly, 53% and 38% of women ages 75 to 79 years and 80 years or older, respectively, reported receipt of Papanicolaou screen within the past 3 years for cervical cancer screening. The prevalence of colorectal cancer screening in men and women was highest in the 75- to 79-year-old group (57%), followed by the USPSTF screening guideline–specific age group (48%) and the group that was 80 years or older (47%). The prevalence of PSA testing within the past year for prostate cancer among men was highest in the 75- to 79-year-old group (57%), followed by the group that was 80 years or older (42%) and the 50- to 74-year-old group (40%).

Among women in the 75- to 79-year-old group, blacks were less likely to report receiving a mammogram within the past 2 years compared with whites (P <. 05) (Table 3). There were no statistically significant differences in screening behaviors by race/ethnicity in the group that was 80 years or older. Among 75- to 79-year-olds, black and Hispanic men and women were significantly less likely to be screened for colorectal cancer compared with whites (P < .005). Similarly, among this same age group, black, Hispanic, and Asian men were less likely to receive a PSA test compared with whites (P < .05 for all comparisons).

Although prevalence rates differ by race in Table 3, separate multivariate logistic regression analyses for each screening test suggest that race/ethnicity was not a significant predictor of screening in older adults. Education and recalling a physician recommendation for a specific test were predictive of screening in adults older than 75 years. Those individuals without a high school diploma were significantly less likely to be screened for breast (OR, 0.4; 95% CI, 0.3-0.7), cervical (OR, 0.4; 95% CI, 0.2-0.8), colorectal (OR, 0.5; 95% CI, 0.3-0.8), and prostate (OR, 0.5; 95% CI, 0.3-0.8) cancer compared with adults older than 75 years with a college degree. Adults older than 75 years were significantly more likely to be screened for breast (OR, 21.4; 95% CI, 16.0-28.6), cervical (OR, 42.1; 95% CI, 25.4-69.8), colorectal (OR, 67.7; 95% CI, 50.5-90.9), and prostate (OR, 44.1; 95% CI, 20.5-94.9) cancer if they recalled that a physician recommended the test. Also, men with more comorbidity were more likely to be screened for prostate cancer compared with men without any self-reported comorbidity (Table 4).

Table 5 presents percentages of people recalling recommendations for screening tests for breast, cervical, colorectal, and prostate cancer by age group and race/ethnicity. Among women, the rate of recalling physician recommendation for mammogram and Papanicolaou screen was highest in the screening guideline–specific age group (69% and 60%, respectively) followed by the group that was 75 to 79 years old group (62% and 48%, respectively) and the group that was 80 years or older (50% and 36%, respectively). The percentage of people recalling physician recommendations for screening for colorectal cancer was highest in the group that was 75 to 79 years old (65%) followed by the screening guideline–specific age group (62%) and the group that was 80 years or older (54%). Among men, the percentage recalling physician recommendation for PSA testing was highest among those who were 75 to 79 years old (62%), followed by those who were 80 years or older (53%) and the screening guideline–specific age group (49%).

Among the guideline specific–age group, several significant racial differences existed with respect to physicians' recommendation of screening tests. Blacks were significantly less likely to recall a physician's recommendation for colorectal screening, mammogram, and Papanicolaou screen compared with whites (P < .005 for all comparisons). Similarly, Hispanics were significantly less likely to recall a physician's recommendation for all types of screening examined (P < .05 for all comparisons). Finally, among the screening guideline–specific age group, Asians were significantly less likely to recall a physician's recommendation for colorectal screening, Papanicolaou screen, and PSA test (P < .05 for all comparisons).

These differences in recall of physician recommendations for colorectal screening for blacks, Hispanics, and Asians were also found in the group that was 75 to 79 years old (P < .01 for all comparisons). Although a statistically significant difference was found in recall of physician recommendations for mammography and PSA testing among Asians compared with whites in the group that was 75 to 79 years old, the sample size was too small for meaningful interpretation. No statistically significant differences were found in the group that was 80 years or older.

We examined the prevalence of cancer screening behaviors in older, racially diverse adults, as well as the extent to which they recalled physician recommendations for screening. A high percentage of older adults undergo cancer screening. Particularly striking are the rates of breast (62%) cervical (53%), colorectal (57%), and prostate cancer (56%) screening in the group that was 75 to 79 years old. Among those 80 years or older, rates of screening remain elevated and include a low of 38% for cervical cancer screening to a high of 50% for breast cancer screening. These persistently elevated rates of screening raise the question of whether the decision to be screened is being made without fully knowing or discussing the risks and benefits.

With heterogeneity in the health status of this older population, it is likely that continued screening for certain population segments is warranted, but making that determination is complex. These national estimates argue for more research that would examine factors that influence clinicians' and patients' decisions to screen or not to screen. A framework has been proposed to guide individualized cancer screening decisions that take into account estimated life expectancy, risk of cancer death from indolent or aggressive disease, and patients' values and preferences.⁵ Another option, used primarily to understand treatment tolerance in older adults, is the use of Comprehensive Geriatric Assessment (CGA),²² a measure of physical function, frailty, cognitive impairments, nutrition, and physical disabilities. This may be useful in individualized cancer screening decisions for older adults, although the evidence for the effectiveness of this tool for cancer prevention is nonexistent. Notable shortcomings of implementing this type of framework for individualized decision making are time, familiarity, and cost. In addition, third-party reimbursement may need to “forgo oversimplified guidelines that do not allow for the application of clinical judgment.”^{5 (p2756)}

Our analyses revealed racial differences in breast, colorectal, and prostate cancer screening among older adults (75-79 years) in the unadjusted prevalence estimates, but these differences were accounted for by low education attainment in the logistic regression model. These findings perhaps point to differences in educational access between blacks and Hispanics compared with whites. Although the education attainment of all races has increased over the past decade, the gap between Hispanics and blacks compared with whites is still significant.²³ These finding suggest that older minority adults from racial groups, perhaps owing to education level, are being screened less frequently than older whites, which demonstrates a continuing pattern of health disparities. Randomized clinical trials and/or leveraging existing population based data sets, such the SEER/Medicare data set, are needed to examine the efficacy of cancer screening in this diverse population of older adults. Also of note is the interesting finding that men with more comorbidity were more likely to be screened for prostate cancer, perhaps reflecting a relationship between higher rates of screening in men who have frequent interaction or encounters with the health care system.

Despite USPSTF guidelines recommending against routine screening for breast, cervical, colorectal, and prostate cancer at the age of 75 years (65 years for cervical cancer), over 50% of physicians are continuing to recommend these screening tests in older men and women. Interestingly, these high recommendation rates continue in the group 80 years or older for colorectal (54%), breast (50%), and prostate (53%). These data could not be assessed to provide insight into whether physician recommendations are initiated as part of the informed decision making process, patient preferences, or objective measures of mortality risk. Findings from the logistic regression suggest that a person's recollection of a physician's recommendation for screening was a significant predictor of screening behavior. This finding reinforces the critical role for health care providers to make informed screening decision for older adults.

We know from studies of older adults' attitudes and preferences for continued screening in later life that 72% of adults 70 years or older report that they would continue cancer screening throughout their lives and almost half of those (43%) would continue despite their physicians recommendation against further screening.^18,24 Other studies in younger adult populations found higher perceived risk for cancer increased screening rates,²⁵ which could not be assessed in this study. Perhaps with the known increase risk of cancer with age, older adults are hypervigilant with their primary care physicians about their desires to be screened. This is an empirical question yet to be examined.

Our analyses should be interpreted in the context of limitations using NHIS data. First, this study relied on self-report data. Therefore, rates of screening may have been overestimated as a result of social desirability.¹² Second, individuals who live in nursing homes, long-term care facilities, or hospice are not included in the survey, so these findings generalize to noninstitutionalized US civilians. Third, current screening recommendations for breast, colorectal, and prostate cancer were not in place at the time of the surveys. Finally, the low numbers of older Asian men and women in our sample provided insufficient power to detect meaningful differences in screening behaviors between these groups and whites.

In the United States, the number of adults 65 years or older, currently estimated at 36.8 million, is expected to double by the year 2030.⁴ Providing high-quality care to this growing population while attempting to contain costs will pose a significant challenge. One strategy is to develop and disseminate evidence-based decision tools to guide clinicians to objectively determine, in conjunction with values and preferences of older adults, whether the benefits of screening outweigh the harms. This approach needs to be equitably distributed across the racially diverse population of older adults at risk for cancer. Prevalence results from this study can serve as a benchmark for progress as we move the science of cancer screening in older, diverse adults forward.

Correspondence: Keith M. Bellizzi, PhD, MPH, Department of Human Development and Family Studies, University of Connecticut, 348 Mansfield Rd, Unit 2058, Storrs, CT 06269 (keith.m.bellizzi@uconn.edu).

Accepted for Publication: September 18, 2011.

Author Contributions:Study concept and design: Bellizzi, Breslau, and Burness. Analysis and interpretation of data: Bellizzi and Waldron. Drafting of the manuscript: Bellizzi and Breslau. Critical revision of the manuscript for important intellectual content: Bellizzi, Burness, and Waldron. Statistical analysis: Waldron. Administrative, technical, and material support: Breslau and Burness. Study supervision: Bellizzi.