Table 1—
Summary Statistics, 1999–2013
| Mean | Standard deviation | Observations | |
|---|---|---|---|
| PM 2.5 (μg/m3) | 10.48 | 7.13 | 1,980,549 |
| Number of beneficiaries | |||
| 65+ | 49,106 | 78,983 | 1,980,549 |
| 65–69 | 13,173 | 20,910 | 1,980,549 |
| 70–74 | 11,672 | 18,802 | 1,980,549 |
| 75–79 | 9,658 | 15,767 | 1,980,549 |
| 80–84 | 7,452 | 12,183 | 1,980,549 |
| 85+ | 7,151 | 11,818 | 1,980,549 |
| Number of FFS beneficiaries | 34,196 | 52,182 | 1,898,236 |
| Continuously enrolled FFS beneficiaries | 26,901 | 39,335 | 1,898,236 |
| Three-day mortality rate | |||
| 65+ | 388.25 | 247.60 | 1,980,549 |
| 65–69 | 135.37 | 264.38 | 1,980,549 |
| 70–74 | 201.83 | 369.19 | 1,980,549 |
| 75–79 | 320.70 | 487.38 | 1,980,549 |
| 80–84 | 526.38 | 787.33 | 1,980,549 |
| 85+ | 1,168.68 | 1,118.87 | 1,980,549 |
| All FFS | 404.84 | 274.51 | 1,898,236 |
| Continuously enrolled FFS | 456.06 | 317.66 | 1,898,236 |
| Three-day inpatient spending, planned and ER | 34,598,644 | 15,236,367 | 1,898,236 |
| Three-day inpatient ER spending | 13,793,534 | 7,831,989 | 1,898,236 |
| Three-day admissions rate, planned and ER | 3,270 | 1,207 | 1,898,236 |
| Three-day ER admissions rate | 1,547 | 707 | 1,898,236 |
| Three-day ER (inpatient and outpatient) visit rate | 4,185 | 1,206 | 1,898,236 |
Notes: Table reports unweighted statistics for the estimation sample. Unit of observation is county-day. All rates are per million Medicare beneficiaries in the relevant group. Spending and admissions variables are only available for fee-for-service (FFS) beneficiaries. Continuously enrolled refers to beneficiaries who have been continuously enrolled in FFS for at least two years. Life-years lost analysis uses variables only available for continuously enrolled FFS beneficiaries. All FFS samples begin in 2001 instead of 1999.