Health data guides · CDC NCHS
Health Data Guides
How CDC NCHS leading-cause-of-death data is collected, what age-adjusted death rates mean for fair state-to-state comparisons, and how to read trends spanning 1999–2017 across all 10 cause categories and 51 states.
Where should you start with mortality data?
Understanding Mortality Data
What CDC mortality statistics measure, how death certificates generate the data, and how to interpret age-adjusted death rates vs. raw counts.
Leading Causes of Death in America
The ten leading causes of death in the US, how rankings changed from 1999 to 2017, and what drives differences between states.
How to Read State Health Statistics
What age-adjusted death rates mean, why they matter for fair comparisons, and regional patterns visible in CDC mortality data.
How Mortality Rates Have Changed: 1999–2017
A 19-year historical analysis of which causes improved, which worsened dramatically, and what drove those shifts in US mortality.
Regional Health Disparities in the US
Why mortality rates vary dramatically by region, the stroke belt, Mountain West suicide patterns, Appalachian COPD, and the drivers behind these gaps.
What Are Age-Adjusted Death Rates and Why They Matter
Age-adjusted rates are essential for fair mortality comparison. How they work, when to use them, and the most common interpretation mistakes.
Deaths of Despair: Suicide and Overdose, 1999-2017
How suicide and drug-overdose deaths rose about 40% from 1999 to 2017 even as heart disease and cancer fell, and what the pattern reveals.
Methodology & Data Sources
All mortality statistics published on PlainHealth are drawn from the United States Centers for Disease Control and Prevention's National Center for Health Statistics (CDC NCHS), delivered through the National Vital Statistics System (NVSS) and retrieved using the CDC WONDER Underlying Cause of Death query interface (ICD-10 codes). Files cover all 50 US states and the District of Columbia from 1999 through the most recent final year released by CDC. Provisional data is not used.
We prefer age-adjusted rates per 100,000 population for all cross-state and cross-year comparisons. Age-adjustment uses the year 2000 US standard population, the convention adopted by CDC NCHS. Age-adjusted rates remove the confounding effect of different state age distributions, so a state with an older population does not appear to have "higher" mortality merely because of demographics. Crude rates and raw death counts are shown alongside for full transparency.
Cause-of-death groupings follow the ICD-10 113 Selected Causes of Death classification used by CDC WONDER. Where a county or demographic subgroup has fewer than 10 deaths in a given year, CDC suppresses the count for confidentiality, we treat suppressed cells as "data not available" rather than zero and omit them from rankings and averages. When a state's age-adjusted rate would be statistically unreliable (denominator too small), we mark it as unreliable instead of publishing it.
Rankings order states by the underlying metric (rate, count, or multi-year change) and preserve ties by listing states alphabetically at the same rank. Date-of-data reflects the CDC WONDER release cycle; the Data covers range on each page names the earliest and latest years available for that cause or state. These pages describe population-level statistics and are not a substitute for medical advice. For diagnosis, treatment, or prevention decisions, consult a qualified healthcare professional.