Table 1 Characteristics of the study cohort over three time periods.
Characteristic | 2004–2006 | 2007–2009 | 2010–2012 |
|---|---|---|---|
Annual number of admissions | 438015 | 423787 | 403882 |
Demographics | |||
  Male sex, no (%) | 218208 (49.9%) | 214746 (50.76%) | 204465 (50.67%) |
  Age (Mean ± SE) | 68.65 ± 0.105 | 67.90 ± 0.137 | 67.29 ± 0.118 |
Income | |||
  Income quartile 1, no (%) | 109542 (25.52%) | 107084 (25.83%) | 107918 (27.27%) |
  Income quartile 2, no (%) | 111779 (26.04%) | 109658 (26.45%) | 99466 (25.14%) |
  Income quartile 3, no (%) | 105967 (24.69%) | 98883 (23.85%) | 98443 (24.88%) |
  Income quartile 4, no (%) | 101811 (23.72%) | 98815 (23.84%) | 89781 (22.69%) |
Comorbidity | |||
  Combined comorbidity score (Mean ± SE) | 3.01 ± 0.039 | 3.23 ± 0.055 | 3.68 ± 0.05 |
Disease stage | |||
  Localized | 245456 (56.03%) | 244713 (57.74%) | 241488 (59.79%) |
  Locally advanced | 22013 (5.02%) | 21701 (5.12%) | 22052 (5.46%) |
  Regional nodal disease | 64827 (14.80%) | 54081 (12.76%) | 40749 (10.08%) |
  Metastatic | 100029 (22.83%) | 96983 (22.88%) | 92864 (22.99%) |
Outcome | |||
  Mortality, no (%) | 19588 (4.47%) | 16244 (3.84%) | 13385 (3.31%) |
  Length of stay (Mean ± SE) | 8.78 ± 0.049 | 8.42 ± 0.043 | 7.952 ± 0.039 |
  Total charge for inhospital stay (Mean ± SE) | 44881 ± 695.83 | 56238 ± 898.67 | 66546 ± 925.70 |
Hospital characteristics | |||
  Rural hospital, no (%) | 61460 (14.04%) | 51300 (12.17%) | 45763 (11.41%) |
  Urban, nonteaching hospital, no (%) | 194276 (44.38%) | 177782 (42.19%) | 156853 (39.14%) |
  Urban, teaching hospital, no (%) | 181939 (41.56%) | 192208 (45.62%) | 198170 (49.44%) |
