Table 3.
Chronic conditions counts and cumulative duration among Medicare Fee‐for‐Service Beneficiaries: N = 20 124 230
| N | Prevalence (%) | Cumulative duration (person‐years 1999‐2015) | |||||
|---|---|---|---|---|---|---|---|
| Mean | Median | Std Dev | Min | Max | |||
| Overall | 20 124 230 | 23.6 | 16.4 | 24.0 | 0 | 216.9 | |
| 0‐1 Chronic conditions | 5 698 784 | 28.3 | 2.6 | 0 | 4.2 | 0 | 17.0 |
| 2‐3 Chronic conditions | 6 263 676 | 31.1 | 17.4 | 15.5 | 11.1 | 0 | 51.0 |
| 4‐5 Chronic conditions | 4 676 475 | 23.2 | 32.9 | 31.9 | 16.8 | 0 | 84.9 |
| 6+ Chronic conditions | 3 485 295 | 17.3 | 56.5 | 55.6 | 26.4 | 0 | 216.9 |
Chronic conditions are identified based upon the Chronic Condition Data Warehouse (CCW) “end‐of‐year” indicators, which indicate whether a beneficiary met the CCW criteria for the condition algorithm as of the end of the calendar year. These variables are available from the CCW Master Beneficiary Summary—Chronic Conditions segment. Duration of exposure to each of the 19 conditions (in person‐years) is calculated from the date of first possible occurrence (01/01/1999) to the end of follow‐up (date of death or 12/31/2015). For beneficiaries with two or more conditions, a duration of zero can arise under two scenarios: (a) in the Medicare claims, the beneficiary has a date of death that is the same as the chronic condition “ever” date, (b) if the beneficiary is alive, the chronic condition “ever” date is 12/31/15, which is the last day of follow‐up.