Using CHIS data to explore Cancer screening disparities in California

Israel De Alba, MD MPHCenter for Health Policy ResearchDepartment of MedicineUniversity of California, Irvine

OverviewUsing CHIS data to explore cancer screening

racial/ethnic disparities: two examples

1. Pap smear use in California: are closing the racial/ethnic gap?

2. Impact of U.S. citizenship status on cancer screening among immigrant women

BackgroundCervical Cancer Screening in California

Nearly 14% of all new cases nationwide are diagnosed in women residing in California

The cervical cancer age adjusted incidence rate in the state is above the national average

BackgroundCervical Cancer Screening in California

California has one of the largest proportions of minority populations in the country; one in every three state inhabitants is of Hispanic origin and one in nine of Asian descent

BackgroundStudy Aims

Aim 1. To assess the impact of race/ethnicity on Pap smear use among women in California

Aim 2. To examine the effect of ethnic sub-groups on cervical cancer screening among Hispanic and Asian women in California

Methods

Inclusion criteria:1. Women age ≥182. No hysterectomy

Outcomes1. Receipt of recent Pap smear

(in past 3 years)

2. Ever having a Pap smear

MethodsStatistical analysis

1. Descriptive statistics2. Bivariable analysis3. Logistic regression4. Generation of prevalence rate

ratios

MethodsLogistic regression models constructed

Population Dependent variable

Main independent variable

Model 1 All women Recent Pap smear

Race/ethnicity

Model 2 All women Pap smear ever

Race/ethnicity

Model 3 Hispanics only

Recent Pap smear

Hispanic sub-group

Model 4 Hispanics only

Pap smear ever

Hispanic sub-group

Model 5 Asians only Recent Pap smear

Asian sub-group

Model 6 Asians only Pap smear ever

Asian sub-group

Methods

Hispanic sub-groupsMexicanCentral AmericanSouth AmericanOther

Methods

Asian Sub-groupsJapaneseFilipinoKoreanChineseVietnameseSouth Asians • (Bangladeshi, Indian, Pakistani, Sri Lankan,

and more than one of these nationalities)

MethodsAdjusting variables in logistic regressionAge

18-30, 31-40, 41-50 and ≥51Educational attainment

< high school, high school, > high schoolAnnual household income

< 200% FPL or ≥ 200% FPLHealth insurance

any coverage or no insuranceSelf-reported health status

excellent, very good or good vs. fair or poorAbility to speak English (only among ethnic sub-

groups)very well, well, not well and not all

Results: all womenDemographics (N=25,228)

Age distribution 18-30 30%31-40 25%41-50 20%≥51 25%

Race/ethnicity: White 50%Hispanic 30%Asian 11%African American 5%Other 4%

Results: all womenPap smear use adjusted prevalence rates ratios

Recent Pap Pap ever

White 1.0 1.0

Hispanic 1.03* .99

Asian .81* .82*

African American 1.03* 1.01

Other .96 .98

* ≤ 0.05

Results: Hispanic subgroup analysisPap smear use adjusted prevalence rate ratios

Recent Pap Pap ever

Mexican 1.0 1.0

Central American 1.06* 1.04

South American 1.07 1.07

Other Hispanic 1.01 .99

* ≤ 0.05

Results: Asian subgroup analysis (N=2,625)Pap smear use adjusted prevalence rate ratios

Recent Pap Pap Ever

Filipino 1.0 1.0

Korean 0.95 0.91

Japanese 0.95 0.84

Chinese 0.95 0.79*

Vietnamese 0.93* 0.78*

South Asian 0.93* 0.73*

* ≤ 0.05

SummaryIn California, Hispanic and African American women are significantly more likely to report having a recent Pap smear as compared to White women and they are as likely to report a Pap smear ever

Asians, however, were significantly less likely to report having a Pap smear recently or ever despite a favorable sociodemographic profile

Summary

Pap smear use rate varied by ethnic subgroup

Mexican women were less likely to report recent or ever Pap smear as compared to Central and South Americans

Summary

Among Asians:• Filipino and Korean women are the most

likely to report recent or ever Pap smear• South Asians, Chinese and Vietnamese

were least likely to report any of these outcomes

Having a usual source of care and income contributes the most to Pap smear use among all women and Asians in California

Health insurance and income are the most important contributors to use of Pap smears among Hispanics

Summary, other findings

Limitations

Self-report of receipt and timing of Pap smearLow response rate for 2001 CHIS (63.7%)

Non-response bias

Generalizability

Specific aim

To evaluate the relationship between U.S. citizenship status and receipt of Pap smears and mammograms among immigrant women in California.

Rationale

Non-U.S. citizen immigrants may be disproportionately affected by access and cultural barriers

California has a higher percentage of non-U.S. citizens than any other state

OutcomesCervical cancer screening among immigrant women age 18 or older without a hysterectomy:

• Pap smear in the past three years• Pap smear ever

Breast cancer screening among immigrant women age 40 or older:

3. Mammogram in the past two years4. Mammogram ever

Statistical analysisMultivariable logistic regression model for each outcomeAdjusting for:

AgeRace/ethnicity Educational attainmentAnnual household incomeHaving health insuranceYears in the U.S.Health statusEnglish language proficiency

Results

6,320 women were included in our analysis of cervical cancer screening; 47% were U.S. citizens

3,828 in the analysis of breast cancer screening; 65% were U.S. citizens

Results

Results

ConclusionsNot being a U.S. citizen is a barrier to receiving cervical and breast cancer screening

Additional research is needed to explore causal factors for differences in cancer screening rates between citizens and non-U.S. citizens

Immigrants, especially those who are not U.S. citizens, should be targeted for improved health care access and appropriate cancer screening.

Using CHIS data to explore cancer screening racial/ethnic disparities: overall impressions

Positive aspectsData easily availableWell designed, standardized questionnairesExcellent “customer service”High proportion of minority populations

Using CHIS data to explore cancer screening racial/ethnic disparities: overall impressions

Minor commentsLow response rate in 2001 CHISLimitations of a phone survey