Black women who live in neighborhoods with high poverty rates are more likely than their counterparts in low-poverty areas to have not been screened for cervical cancer within the past two years, according to a nationwide study.1 In addition, black women who are 40 or older or obese, who smoke or who are not college graduates have an increased likelihood of not having been screened recently. Even after adjustment for these and other individual risk factors, however, the association between neighborhood poverty and women's screening status remains.
Current clinical guidelines recommend that women younger than 65 be screened for cervical cancer every 1–3 years. Some evidence suggests that women who live in areas with low poverty rates have higher rates of cervical cancer screening than women who live in high-poverty areas. However, it is unclear whether neighborhood-level risk factors are independent of established individual risk factors. To find out, researchers analyzed data from the Black Women's Health Study. The longitudinal study, launched in 1995, enrolled 59,090 black women aged 21–69, most of them subscribers to Essence magazine. The current analysis focused on 40,009 participants who, at baseline, were younger than 65, had not had cervical cancer or a hysterectomy, provided information on all relevant variables and had an address that could be coded by neighborhood poverty level using census data.
The outcome of interest was the self-reported length of time that had elapsed since participants' last cervical cancer screening; a screening was categorized as recent if it had occurred within two years. The researchers investigated a variety of individual-level predictors of recent screening, including age, marital status, parity, cigarette use, body mass index and family history of breast cancer. To examine neighborhood poverty, they identified the 1990 census tract (a fairly homogenous group of about 3,000 residents) that corresponded to each participant's 1995 address and determined the proportion of residents who lived in poverty in 1990. They also examined poverty rates at the state level.
Overall, 8% of participants had not received a Pap smear in the preceding two years. However, rates exceeded 10% in several subgroups of women, including those who had not attended college, never-married women, women 50 or older, and women with a body mass index of 30 or more kg'm2. Professional women and those with one or two children (as opposed to nulliparous women or those with three or more children) had a reduced likelihood of not having been screened.
In a multivariate analysis, several of these individual-level factors remained significant predictors that a woman had not received a recent Pap smear—notably, education, marital status and age. Women who had not completed high school, for example, were much more likely than women who had attended graduate school to have not been screened (odds ratio, 1.8); odds ratios were also elevated, though to a lesser extent, for high school graduates (1.5) and women who had attended college but had not graduated (1.3). Women who had never married were more likely than their married counterparts to have not been screened recently (1.9), as were women who were separated (1.4), divorced (1.2) or widowed (1.4). The odds of nonscreening were substantially higher among women aged 40–49 (1.9), 50–59 (2.1) and 60–64 (2.4) than among women 29 and younger.
Cigarette use, body mass index and parity were also associated with screening status. Current smokers were more likely than nonsmokers to have not been screened recently (odds ratio, 1.2). Women who were very thin or obese were also at risk; compared with women whose body mass index was 20–24.9, those whose body mass index was less than 20 or 30 or greater had an increased likelihood of nonscreening (1.3 and 1.6, respectively). Women with one or two children were less likely than nulliparous women to be overdue for screening (0.6 and 0.8, respectively).
Further analysis revealed that neighborhood poverty rate was a significant predictor of screening status, even after the researchers controlled for individual risk factors. Women who lived in census tracts with poverty rates of at least 20% were more likely than those who resided in tracts with poverty rates below 5% to have not been screened (odds ratio, 1.2). Because education level was a strong predictor of screening status, the investigators examined whether neighborhood-level effects were significant among women with at least a college education; even in this group, those who lived in neighborhoods with a poverty rate greater than 20% were more likely than women who lived in census tracts with poverty rates below 5% to have not been screened (1.3). Although state of residence predicted screening status, the association did not appear to be related to state poverty levels. "It is not clear what is causing the differences between states," the researchers note.
Despite the study's limitations—including a reliance on self-reports of Pap smear history and the use of a nonrandom sample of black women—the researchers observe that their results echo those of earlier studies that found that lower education, older age, obesity and smoking are associated with not having had a recent Pap test. "The study adds to the literature by demonstrating that census tract and state factors influence cervical cancer screening behaviors above and beyond individual factors," the investigators note. Given these results, they conclude that "community outreach programs should focus on high-poverty neighborhoods to decrease the proportion of black women who are not adherent to cervical cancer screening recommendations."—P. Doskoch
1. Datta G et al., Individual-, neighborhood-, and state-level socioeconomic predictors of cervical carcinoma screening among U.S. black women: a multilevel analysis, Cancer, 2006, 106(3):664–669.