Insurance Status, Age, and Cervical Cancer Stage at Diagnosis
Insurance Status, Age, and Cervical Cancer Stage at Diagnosis
Approximately 10.12% of patients in our sample were uninsured, 17.54% were Medicaid recipients, 2.94% were younger Medicare recipients, 12.74% were older Medicare recipients, 52.24% were privately insured, and 4.42% had missing data for insurance status (Table 1). The average age at diagnosis was 49.68 years (SD = 14.13). A higher percentage of Medicaid, uninsured, and younger Medicare patients than of privately insured patients were African American or Hispanic. Histologic types varied by insurance type. Among privately insured patients, 23.98% were diagnosed with adenocarcinoma, as were 12.27% of the uninsured, 11.37% of Medicaid recipients, and 14.39% of younger Medicare recipients.
Approximately 55.45% of privately insured patients, 36.37%of uninsured patients, 40.15% of Medicaid recipients, 42.29% of younger Medicare recipients, and 30.88% of older Medicare recipients were diagnosed with stage I disease (Table 1). Stage varied greatly by age: the proportion of patients diagnosed with stage I tumors declined by 0.77% with each additional year, and stage IV tumors increased by 0.27% for each additional year (Figure A, available as a supplement to the online version of this article at http://www.ajph.org).
When we examined the combined effect of age and insurance type, we found that privately insured patients aged 18 to 50 years had much lower rates of advanced-stage disease than did patients with other insurance types (Figure 1a). However, the rates of late-stage disease among privately insured patients approached convergence with other patients with increasing age. Privately insured patients aged 18 to 34 years had the lowest rate of advanced-stage disease (13.31%); uninsured patients aged 55 to 59 years had the highest rate (46.72%). NHIS data also showed differences in cervical cancer screening by insurance type and age, with higher screening rates among privately insured and younger women (Figure 1b). Uninsured women aged 50 years and older had the lowest Pap test rates.
(Enlarge Image)
Figure 1.
Invasive cervical cancer diagnoses and screening, by age group and insurance category, for (a) late-stage diagnosis and (b) Papanicolaou test in past 3 years: United States.
In multivariable models predicting moderate disease (stage II), age was the strongest predictor: patients aged 50 years and older were nearly twice as likely as patients aged 21 to 34 years to be diagnosed with stage II disease (Table 2). Uninsured and Medicaid-insured patients were respectively 1.43 and 1.32 times as likely as privately insured patients to be diagnosed with stage II disease. The likelihood of stage II disease was also higher among younger and older Medicare patients than among the privately insured. Patients diagnosed with adenocarcinoma or adenosquamous–glassy cell carcinomas were less likely than patients with squamous cell carcinoma to be diagnosed with stage II cancer. We observed only a tentative association between race/ethnicity and stage II disease.
In multivariable models predicting advanced-stage disease (stages III and IV), age was the most important predictor, followed by insurance type (Table 2). The risk of advanced-stage disease among women aged 50 years and older was 2.2 to 2.5 times that of patients aged 21 to 34 years. Uninsured and Medicaid patients were respectively 1.44 and 1.37 times as likely to be diagnosed with stage III or IV as with stage I disease. Younger and older Medicare patients were also more likely than others to be diagnosed with stage III or IV disease; however, their risk of advanced disease was not as pronounced as that of uninsured and Medicaid patients. Women diagnosed with adenocarcinomas were less likely to be diagnosed with late stage compared to squamous cell carcinomas. African Americans had a slightly higher risk of advanced-stage disease, and Hispanics and other race/ethnicity groups had a lower risk than did Whites.
We also examined associations with age and other covariates in multivariable models stratified by insurance type (Table 3). Although privately insured patients had lower percentages of advanced-stage disease across all age groups, they also had the steepest gradient of increasing relative risk by age of all insurance groups. Among privately insured women, we found an approximately tripled relative risk for women aged 55 years and older; among women in other insurance categories, maximum relative risks were around 2. Among uninsured, Medicaid-insured, and Medicare-insured patients, Hispanics and women of other races were less likely to be diagnosed with late-stage disease than were White women. Among privately insured and older Medicare-insured women, African Americans were more likely than Whites to be diagnosed with late-stage disease. Patients with adenocarcinomas were less likely than women with squamous cell carcinoma to be diagnosed with late-stage disease, regardless of insurance type.
The NCDB cervical cancer coverage rate was 88% of the North American Association of Central Cancer Registries' gold and silver registries in 2006 and 83% in 2004. The NCDB and SEER cases had similar age distributions, although SEER had a higher percentage (23%) of Hispanic patients and a lower percentage of unknown race/ethnicity (1%). The proportion of stage I patients in SEER (47.78%) was essentially the same as in the NCDB (46.84%); however, the proportion of stage II patients was higher in the NCDB (23.35%) than in SEER (16.38%). As a result, the NCDB had fewer stage III (19.61% vs 22.16%) and stage IV (10.20% vs 13.68%) cases than did SEER. These stage distributions point to slight differences between our study cohort and population-based registries. When we compared the 5097 (6.63%) NCDB cervical cancer patients who were missing staging data to the 69 739 (93.37%) who were not, we found no association with missing stage for race, geographic region, or area-level education in our multivariable analysis. Patients aged 70 to 85 years (RR = 1.19; 95% CI = 1.03, 1.37) and younger Medicare patients (RR = 1.25; 95% CI = 1.08, 1.45) were more likely to have missing data for stage.
Results
Approximately 10.12% of patients in our sample were uninsured, 17.54% were Medicaid recipients, 2.94% were younger Medicare recipients, 12.74% were older Medicare recipients, 52.24% were privately insured, and 4.42% had missing data for insurance status (Table 1). The average age at diagnosis was 49.68 years (SD = 14.13). A higher percentage of Medicaid, uninsured, and younger Medicare patients than of privately insured patients were African American or Hispanic. Histologic types varied by insurance type. Among privately insured patients, 23.98% were diagnosed with adenocarcinoma, as were 12.27% of the uninsured, 11.37% of Medicaid recipients, and 14.39% of younger Medicare recipients.
Approximately 55.45% of privately insured patients, 36.37%of uninsured patients, 40.15% of Medicaid recipients, 42.29% of younger Medicare recipients, and 30.88% of older Medicare recipients were diagnosed with stage I disease (Table 1). Stage varied greatly by age: the proportion of patients diagnosed with stage I tumors declined by 0.77% with each additional year, and stage IV tumors increased by 0.27% for each additional year (Figure A, available as a supplement to the online version of this article at http://www.ajph.org).
When we examined the combined effect of age and insurance type, we found that privately insured patients aged 18 to 50 years had much lower rates of advanced-stage disease than did patients with other insurance types (Figure 1a). However, the rates of late-stage disease among privately insured patients approached convergence with other patients with increasing age. Privately insured patients aged 18 to 34 years had the lowest rate of advanced-stage disease (13.31%); uninsured patients aged 55 to 59 years had the highest rate (46.72%). NHIS data also showed differences in cervical cancer screening by insurance type and age, with higher screening rates among privately insured and younger women (Figure 1b). Uninsured women aged 50 years and older had the lowest Pap test rates.
(Enlarge Image)
Figure 1.
Invasive cervical cancer diagnoses and screening, by age group and insurance category, for (a) late-stage diagnosis and (b) Papanicolaou test in past 3 years: United States.
In multivariable models predicting moderate disease (stage II), age was the strongest predictor: patients aged 50 years and older were nearly twice as likely as patients aged 21 to 34 years to be diagnosed with stage II disease (Table 2). Uninsured and Medicaid-insured patients were respectively 1.43 and 1.32 times as likely as privately insured patients to be diagnosed with stage II disease. The likelihood of stage II disease was also higher among younger and older Medicare patients than among the privately insured. Patients diagnosed with adenocarcinoma or adenosquamous–glassy cell carcinomas were less likely than patients with squamous cell carcinoma to be diagnosed with stage II cancer. We observed only a tentative association between race/ethnicity and stage II disease.
In multivariable models predicting advanced-stage disease (stages III and IV), age was the most important predictor, followed by insurance type (Table 2). The risk of advanced-stage disease among women aged 50 years and older was 2.2 to 2.5 times that of patients aged 21 to 34 years. Uninsured and Medicaid patients were respectively 1.44 and 1.37 times as likely to be diagnosed with stage III or IV as with stage I disease. Younger and older Medicare patients were also more likely than others to be diagnosed with stage III or IV disease; however, their risk of advanced disease was not as pronounced as that of uninsured and Medicaid patients. Women diagnosed with adenocarcinomas were less likely to be diagnosed with late stage compared to squamous cell carcinomas. African Americans had a slightly higher risk of advanced-stage disease, and Hispanics and other race/ethnicity groups had a lower risk than did Whites.
We also examined associations with age and other covariates in multivariable models stratified by insurance type (Table 3). Although privately insured patients had lower percentages of advanced-stage disease across all age groups, they also had the steepest gradient of increasing relative risk by age of all insurance groups. Among privately insured women, we found an approximately tripled relative risk for women aged 55 years and older; among women in other insurance categories, maximum relative risks were around 2. Among uninsured, Medicaid-insured, and Medicare-insured patients, Hispanics and women of other races were less likely to be diagnosed with late-stage disease than were White women. Among privately insured and older Medicare-insured women, African Americans were more likely than Whites to be diagnosed with late-stage disease. Patients with adenocarcinomas were less likely than women with squamous cell carcinoma to be diagnosed with late-stage disease, regardless of insurance type.
The NCDB cervical cancer coverage rate was 88% of the North American Association of Central Cancer Registries' gold and silver registries in 2006 and 83% in 2004. The NCDB and SEER cases had similar age distributions, although SEER had a higher percentage (23%) of Hispanic patients and a lower percentage of unknown race/ethnicity (1%). The proportion of stage I patients in SEER (47.78%) was essentially the same as in the NCDB (46.84%); however, the proportion of stage II patients was higher in the NCDB (23.35%) than in SEER (16.38%). As a result, the NCDB had fewer stage III (19.61% vs 22.16%) and stage IV (10.20% vs 13.68%) cases than did SEER. These stage distributions point to slight differences between our study cohort and population-based registries. When we compared the 5097 (6.63%) NCDB cervical cancer patients who were missing staging data to the 69 739 (93.37%) who were not, we found no association with missing stage for race, geographic region, or area-level education in our multivariable analysis. Patients aged 70 to 85 years (RR = 1.19; 95% CI = 1.03, 1.37) and younger Medicare patients (RR = 1.25; 95% CI = 1.08, 1.45) were more likely to have missing data for stage.
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