Shares of population groups excluded from the full DRV sample by German region
| West Germany (% of full DRV sample) | East Germany (% of full DRV sample) | |
| Not covered by compulsory health insurance | 17.4 | 4.3 |
| Former miners | 5.7 | 8.9 |
| Foreign citizenship | 5.1 | 0.6 |
| Ethnic German repatriates | 5.6 | 1.4 |
| Final study population (restricted DRV sample) | 68.9 | 85.4 |
DRV, Deutsche Rentenversicherung.