Health Outcomes
Current Asthma by County — US Rankings
CDC PLACES 2023 · Age-adjusted prevalence · All 3,144 US counties
Current asthma is the share of adults who were told they had asthma and report they still have it — distinct from the lifetime measure. PLACES uses age-adjusted prevalence from BRFSS to strip out the effect of a county skewing young or old. The measure correlates with air-quality and housing-quality patterns, but the survey does not record either, so the rankings should not be read as a pollution proxy. Counties with high current-asthma prevalence often have lower-than-average asthma management indicators, but the PLACES dataset does not include controller-medication adherence at the county level.
How this ranking is built
Source: CDC PLACES 2023 release. Methodology: BRFSS survey responses pooled across years, fitted with a small-area statistical model, age-adjusted to the 2000 US standard population. Confidence intervals (95%) are shown for each county — wider intervals indicate more uncertainty in the modeled estimate, typically driven by smaller populations.
Lowest Current Asthma Rates — Top 100 Counties
Counties with the lowest reported current asthma prevalence — these counties show the most favorable position on this measure.
Best 100 counties for Current Asthma.
Highest Current Asthma Rates — Bottom 100 CountiesCounties with the highest reported current asthma prevalence.
Worst 100 counties for Current Asthma.
What this ranking suggests
Asthma prevalence is a useful starting point for local public-health teams; for clinical management questions, state Medicaid utilization data and EPA AirNow PM2.5 rankings carry more signal. Pair the current-asthma ranking with the air-quality data on each county page to see whether prevalence and ambient PM2.5 trend together for a specific place.
Methodology notes & limitations
Estimates are statistical model outputs, not direct measurements. Small counties have wider confidence intervals; treat narrow rank differences in those rows as within-noise. Counties where the underlying population is too small to support modeling are suppressed entirely (about 1% of US counties). All measures are age-adjusted to the 2000 US standard population. The PLACES dataset uses BRFSS self-reported data — self-report introduces known direction-of-bias in some measures (BMI is under-reported; binge drinking is under-reported), but the bias is roughly uniform across counties so ranking comparability is preserved. See the methodology page for full data-pipeline documentation.
Data source: CDC PLACES 2023 release. Measure ID: CASTHMA.