Table 1.
Study population of Medicare beneficiaries treated in hospital in 2011-14 by age of treating physician. Figures are percentage unless otherwise specified
| Physician age (years) | |||||
|---|---|---|---|---|---|
| <40 (n=10 177) | 40-49 (n=8016) | 50-59 (n=3331) | ≥60 (n=1086) | P value | |
| Physician characteristics | |||||
| Mean (SD) age (years) | 35.3 (2.6) | 43.89 (2.8) | 53.8 (2.9) | 63.7 (3.5) | <0.001 |
| Women | 39.0 | 34.4 | 28.7 | 15.7 | <0.001 |
| Mean (SD) years of experience since completion of residency | 4.9 (2.7) | 10.9 (4.3) | 18.1 (6.7) | 28.6 (8.6) | <0.001 |
| MD (allopathic) | 93.4 | 95.1 | 95.2 | 97.5 | <0.001 |
| Annual No of admissions/physician* | 136 | 156 | 155 | 127 | <0.001 |
| Patient characteristics | |||||
| No of Medicare admissions in 2011-13 | 309 020 | 280 894 | 115 660 | 30 963 | |
| Mean (SD) age (years) | 80.5 (8.5) | 80.6 (8.5) | 80.5 (8.5) | 80.6 (8.6) | 0.01 |
| Women | 60.7 | 60.5 | 60.3 | 60.3 | 0.40 |
| Race: | |||||
| White | 82.6 | 82.6 | 83.2 | 83.2 | 0.72 |
| Black | 10.2 | 9.7 | 9.4 | 9.4 | 0.53 |
| Hispanic | 4.3 | 4.7 | 4.7 | 4.5 | 0.47 |
| Other | 3.0 | 3.0 | 2.7 | 3.0 | 0.31 |
| Median household income ($) | 58 240 | 57 858 | 55 133 | 53 167 | 0.06 |
| Medicaid status | 22.6 | 23.3 | 24.2 | 25.5 | 0.01 |
| No of Elixhauser comorbidities | 3.4 | 3.4 | 3.4 | 3.4 | <0.001 |
| Elixhauser comorbidity score† | 6.7 | 6.7 | 6.8 | 6.9 | <0.001 |
| Comorbidities: | |||||
| Congestive heart failure | 19.8 | 19.7 | 19.7 | 20.3 | <0.001 |
| Chronic obstructive pulmonary disease | 24.4 | 25.2 | 26.1 | 27.1 | <0.001 |
| Diabetes | 31.5 | 31.5 | 32.0 | 32.3 | 0.44 |
| Renal failure | 22.5 | 22.0 | 22.2 | 22.3 | 0.88 |
| Neurological disorders | 15.3 | 15.5 | 16.2 | 16.8 | <0.001 |
| Cancer | 7.2 | 7.0 | 6.9 | 7.3 | 0.03 |
| Mental illness | 15.2 | 15.0 | 15.4 | 15.8 | 0.14 |
*Estimated using facts that our sample was 20% random sample of fee-for-service Medicare beneficiaries, that proportion of all Medicare beneficiaries with Medicare Advantage plans is about 30%, and that Medicare beneficiaries (including fee-for-service plus Medicare Advantage) comprise 40% of all hospital admissions in US. See appendix for details.
†Composite score developed by van Walraven et al36 was used to combine Elixhauser comorbidities into single numeric score.