1 Study overview

This cross-sectional study examines colorectal cancer screening among Arkansas adults aged 45–75 using the 2022 and 2024 Behavioral Risk Factor Surveillance System (BRFSS) public-use datasets. The primary outcome is being up to date with screening according to the CDC calculated colorectal screening variable.

Estimates account for BRFSS sampling weights, strata, and primary sampling units. Survey-weighted logistic regression assesses associations with age, sex, race and ethnicity, education, income, insurance, access to a personal healthcare provider, metropolitan residence, smoking, and survey year.

We also evaluate age-group interactions and perform sensitivity analyses using alternative age ranges and inverse-probability weighting for observed screening outcomes. Associations are observational and should not be interpreted as causal effects.

2 Data sources and study sample

The study uses the CDC 2022 and 2024 BRFSS annual public-use SAS transport files. The import step retains Arkansas records (state code 5) and caches the selected variables locally for subsequent runs.

## Arkansas_2022 Arkansas_2024 
##          5309          5344

Respondent counts refer to the Arkansas annual BRFSS records before age and outcome restrictions.

2.1 Harmonization across survey years

Some variable names change suffix between years (for example _CRCREC2 in 2022 and _CRCREC3 in 2024), so each is picked up by its prefix.

2.2 Variable definitions and recoding

The original CDC variables are retained in the analysis dataset alongside recoded fields. The categories below correspond to the model inputs.

Analysis variable Source variable Operational definition
Up to date with screening _CRCREC2 (2022), _CRCREC3 (2024) Yes = 1; overdue or never screened = 0; unavailable response = missing
Age group _AGE80 45–54, 55–64, 65–75 years; 65–75 is the model reference
Sex _SEX Female (reference), male
Race/ethnicity _IMPRACE White (reference), Black, Hispanic, other
Education _EDUCAG College graduate (reference), some college, high school, less than high school
Household income _INCOMG $50,000 or more (reference), $25,000–49,999, under $25,000, not reported
Insurance _HLTHPL Insured (reference), uninsured
Personal healthcare provider PERSDOC variables Has provider (reference), no provider
Metropolitan residence _METSTAT Metropolitan (reference), nonmetropolitan
Smoking _SMOKER Never (reference), former, current
Survey year Interview year 2022 (reference), 2024

Unknown, refused, or inapplicable responses remain missing unless a separate not reported group is explicitly specified. Missing screening outcomes are not treated as unscreened. The underlying source fields are not overwritten.

2.3 Survey design

## Original Arkansas records by year:
## 
## 2022 2024 
## 5309 5344
## Screening-valid records by year:
## Year
## 2022 2024 
## 2654 2688
## Missing screening outcome among age 45–75 by year:
##       
## year   FALSE TRUE
##   2022  2654  454
##   2024  2688  250

3 Survey-weight and prevalence quality checks

The verification compares weighted prevalence with reference estimates calculated directly from the source-year data using _LLCPWT. A tolerance of 0.15 percentage points is used to identify unexpected changes in data processing or weight selection.

Year Weighted screening (%) Reference estimate (%)
2022 2022 64.0 64.0
2024 2024 68.1 68.1

4 Screening prevalence by population group

Colorectal cancer screening by participant characteristics
Characteristic Group Respondents Screened (%) 95% CI lower 95% CI upper
Survey year 2022 2654 64.0 61.8 66.3
Survey year 2024 2688 68.1 65.9 70.2
Age group 65-75 2305 79.7 77.7 81.7
Age group 45-54 1313 45.4 42.3 48.6
Age group 55-64 1724 72.3 69.8 74.8
Sex Female 2943 68.4 66.3 70.5
Sex Male 2399 63.8 61.4 66.1
Race and ethnicity White 4312 68.1 66.4 69.7
Race and ethnicity Black 662 66.1 61.5 70.7
Race and ethnicity Hispanic 118 37.4 27.4 47.4
Race and ethnicity Other 250 60.6 52.8 68.4
Education College graduate 1810 71.3 68.8 73.8
Education Some college 1481 69.4 66.6 72.2
Education High school 1669 62.7 59.9 65.4
Education Less than high school 371 57.2 51.3 63.0
Household income $50,000 or more 2216 68.4 66.0 70.7
Household income $25,000-49,999 1242 67.0 63.7 70.3
Household income Under $25,000 1068 62.2 58.6 65.8
Household income Not reported 816 63.8 59.7 67.9
Health insurance Insured 4911 68.4 66.8 70.0
Health insurance Uninsured 192 29.4 21.7 37.2
Personal healthcare provider Has provider 4992 69.2 67.7 70.8
Personal healthcare provider No provider 312 27.8 22.0 33.6
Metropolitan status Metropolitan 2843 68.1 66.0 70.2
Metropolitan status Nonmetropolitan 2499 63.5 61.1 65.8
Smoking status Never 2730 67.3 65.2 69.5
Smoking status Former 1567 69.5 66.6 72.4
Smoking status Current 974 57.9 54.2 61.7

5 Screening modality indicators by income

Test Income Percent Lower Upper
Colonoscopy within 10 years $50,000 or more 64.2 61.9 66.6
Colonoscopy within 10 years $25,000-49,999 62.5 59.1 66.0
Colonoscopy within 10 years Under $25,000 54.7 51.1 58.4
Colonoscopy within 10 years Not reported 58.8 54.6 63.0
Stool blood test within 1 year $50,000 or more 6.8 5.6 8.0
Stool blood test within 1 year $25,000-49,999 7.1 5.5 8.8
Stool blood test within 1 year Under $25,000 9.9 7.6 12.1
Stool blood test within 1 year Not reported 6.0 4.2 7.7
Stool DNA test within 3 years $50,000 or more 3.2 2.4 4.1
Stool DNA test within 3 years $25,000-49,999 4.7 2.8 6.6
Stool DNA test within 3 years Under $25,000 5.6 3.8 7.3
Stool DNA test within 3 years Not reported 3.6 2.1 5.1

6 Multivariable logistic regression

Odds ratios below 1 mean lower odds of being up to date than the reference group. Reference groups: age 65-75, female, White, 2022, college graduate, income of $50,000 or more, insured, has a provider, metropolitan, never smoked.

Model 1: demographics
Characteristic Adjusted odds ratio 95% CI lower 95% CI upper P-value
Age 45-54 0.218 0.183 0.261 0.000
Age 55-64 0.678 0.568 0.810 0.000
Sex: Male 0.805 0.695 0.933 0.004
Race/ethnicity: Black 0.994 0.794 1.244 0.960
Race/ethnicity: Hispanic 0.368 0.238 0.570 0.000
Race/ethnicity: Other 0.878 0.616 1.251 0.471
Survey year 2024 1.263 1.091 1.462 0.002
Model 2: + education and income
Characteristic Adjusted odds ratio 95% CI lower 95% CI upper P-value
Age 45-54 0.203 0.168 0.244 0.000
Age 55-64 0.665 0.556 0.795 0.000
Sex: Male 0.816 0.702 0.948 0.008
Race/ethnicity: Black 1.058 0.846 1.323 0.623
Race/ethnicity: Hispanic 0.409 0.262 0.637 0.000
Race/ethnicity: Other 0.901 0.629 1.291 0.570
Survey year 2024 1.226 1.058 1.422 0.007
Education: Some college 0.890 0.734 1.080 0.237
Education: High school 0.653 0.540 0.790 0.000
Education: Less than high school 0.589 0.434 0.799 0.001
Household income: $25,000-49,999 0.858 0.698 1.055 0.146
Household income: Under $25,000 0.791 0.635 0.984 0.036
Household income: Not reported 0.723 0.573 0.913 0.006
Model 3 (main): + insurance, provider, residence, smoking
Characteristic Adjusted odds ratio 95% CI lower 95% CI upper P-value
Age 45-54 0.233 0.191 0.284 0.000
Age 55-64 0.753 0.624 0.909 0.003
Sex: Male 0.854 0.729 1.002 0.052
Race/ethnicity: Black 1.070 0.837 1.368 0.589
Race/ethnicity: Hispanic 0.526 0.317 0.875 0.013
Race/ethnicity: Other 0.885 0.600 1.307 0.540
Survey year 2024 1.228 1.051 1.436 0.010
Education: Some college 0.960 0.784 1.176 0.696
Education: High school 0.746 0.609 0.915 0.005
Education: Less than high school 0.682 0.488 0.953 0.025
Household income: $25,000-49,999 0.976 0.785 1.213 0.826
Household income: Under $25,000 0.890 0.703 1.127 0.334
Household income: Not reported 0.781 0.605 1.007 0.057
Insurance: Uninsured 0.440 0.272 0.712 0.001
Provider: No provider 0.279 0.197 0.396 0.000
Residence: Nonmetropolitan 0.724 0.618 0.848 0.000
Smoking: Former 1.093 0.909 1.314 0.347
Smoking: Current 0.844 0.680 1.047 0.124

7 Effect modification analyses

Each interaction is added to the main model and tested with a Wald test.

Interaction F df p
Age group x income 1.136 6 0.339
Age group x sex 1.921 2 0.147
Age group x survey year 0.180 2 0.835

7.1 Income within each age group

Adjusted odds ratios for income, by age group
Age group Characteristic Adjusted odds ratio 95% CI lower 95% CI upper P-value
45-54 Household income: $25,000-49,999 0.837 0.562 1.246 0.381
45-54 Household income: Under $25,000 0.856 0.585 1.253 0.424
45-54 Household income: Not reported 0.984 0.604 1.601 0.947
55-64 Household income: $25,000-49,999 0.937 0.656 1.338 0.722
55-64 Household income: Under $25,000 0.881 0.607 1.278 0.503
55-64 Household income: Not reported 0.714 0.476 1.070 0.102
65-75 Household income: $25,000-49,999 0.717 0.497 1.035 0.076
65-75 Household income: Under $25,000 0.523 0.343 0.797 0.003
65-75 Household income: Not reported 0.531 0.361 0.782 0.001

7.2 Change from 2022 to 2024 within each age group

Age group Year Percent Lower Upper
65-75 2022 78.7 75.8 81.6
45-54 2022 41.9 37.4 46.3
55-64 2022 69.3 65.5 73.1
65-75 2024 80.6 77.8 83.4
45-54 2024 48.4 44.0 52.9
55-64 2024 75.2 72.0 78.5

8 Secondary analysis: never screened

Adjusted odds ratios for never having been screened
Characteristic Adjusted odds ratio 95% CI lower 95% CI upper P-value
Age 45-54 6.392 5.123 7.975 0.000
Age 55-64 1.536 1.228 1.921 0.000
Sex: Male 1.264 1.060 1.508 0.009
Race/ethnicity: Black 1.056 0.807 1.381 0.691
Race/ethnicity: Hispanic 2.065 1.224 3.482 0.007
Race/ethnicity: Other 0.997 0.650 1.528 0.989
Survey year 2024 0.744 0.625 0.886 0.001
Education: Some college 1.037 0.826 1.301 0.755
Education: High school 1.357 1.083 1.701 0.008
Education: Less than high school 1.508 1.046 2.175 0.028
Household income: $25,000-49,999 1.013 0.795 1.292 0.914
Household income: Under $25,000 1.173 0.906 1.518 0.226
Household income: Not reported 1.222 0.918 1.625 0.169
Insurance: Uninsured 2.231 1.355 3.673 0.002
Provider: No provider 3.417 2.390 4.884 0.000
Residence: Nonmetropolitan 1.280 1.073 1.527 0.006
Smoking: Former 0.898 0.733 1.102 0.303
Smoking: Current 1.125 0.884 1.433 0.339

9 Screening by age and household income

10 Analysis sample sizes

## Valid screening outcomes: 5342
## Full adjusted regression sample: 4999

11 Sensitivity analyses

CDC’s calculated colorectal screening indicators differ by survey year: _CRCREC2 in 2022 and _CRCREC3 in 2024. The source documentation also specifies differences in the underlying age information used to construct these indicators. We therefore examine the screening trend in narrower age ranges. These analyses assess robustness; they do not make the CDC indicators fully equivalent across years.

11.1 Screening by year in narrower age ranges

If the estimated time trend is comparable when excluding participants near the lower/upper boundaries, this supports robustness to the chosen age range, but does not prove that the outcome algorithms are identical.

Age-range sensitivity, with correct final BRFSS survey weights
Age_range Year Rate_pct CI_low CI_high
45-75 (primary) 2022 64.03 61.75 66.30
45-75 (primary) 2024 68.08 65.93 70.24
50-75 2022 69.20 66.87 71.54
50-75 2024 74.05 71.93 76.18
50-74 2022 68.78 66.39 71.17
50-74 2024 74.02 71.86 76.19
55-74 2022 73.51 71.00 76.03
55-74 2024 77.99 75.81 80.18 
## 
## Percentage-point changes (2024 minus 2022):
## 45-75 (primary): 4.05
## 50-75: 4.85
## 50-74: 5.24
## 55-74: 4.48

11.2 Missing-outcome patterns

The counts below are unweighted sample characteristics, not estimated population prevalences. Missing screening outcomes can reflect nonresponse, question skip patterns or incomplete information for the CDC-derived outcome; we do not assume missing means unscreened.

## 
## Outcome availability by year (unweighted):
##       Observed
## Year      0    1
##   2022  454 2654
##   2024  250 2688
## 
## Outcome availability by age and year (unweighted):
## , , Observed = 0
## 
##       Age
## Year   45-49 50-54 55-64 65-75
##   2022    51   111   131   161
##   2024    25    34    93    98
## 
## , , Observed = 1
## 
##       Age
## Year   45-49 50-54 55-64 65-75
##   2022   287   356   845  1166
##   2024   323   347   879  1139

11.3 Inverse-probability weighting for observed screening outcomes

Inverse-probability weighting models the probability of an observed screening outcome using available demographic and socioeconomic variables. Observed responses receive the final survey weight multiplied by the inverse estimated observation probability. This sensitivity analysis addresses measured patterns in outcome availability; it cannot rule out bias from unmeasured missingness or differences between the yearly outcome definitions.

Missingness sensitivity with final raked weight
Year Original_pct Original_LCL Original_UCL IPW_pct IPW_LCL IPW_UCL
2022 64.03 61.76 66.30 63.31 60.89 65.73
2024 68.08 65.93 70.24 67.75 65.57 69.93 
## 
## Original percentage-point change: 4.06
## IPW-adjusted percentage-point change: 4.44
## 
## Observed-case inverse observation probability (weight multiplier):
##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
##   1.023   1.047   1.062   1.128   1.102   4.916
## 
## Number of complete screening outcomes: 5342

12 Interpretation and limitations

The primary results describe survey-weighted associations with screening, not causal relationships. The two survey years use CDC-derived screening indicators that are not perfectly interchangeable, and screening history is self-reported. Outcome nonresponse and complete-case regression may introduce selection bias. The inverse-probability analysis relies on assumptions about missing outcomes given the observed covariates; its confidence intervals do not include uncertainty from fitting the observation model. Results should not be interpreted as direct evidence of an effect of state policy changes.

13 Data and methods references