Table 1. Hospitals and populations studied in France.
| Hospital | N = 609 | % |
| Monthly volume of stays per hospital, mean (SD) | 237.0 (349.7) | - |
| Monthly temperature per hospital, mean (SD) | 16.9 (1.8) | - |
| Status | ||
| Teaching | 48 | 7.9 |
| Public or private non-for-profit | 260 | 42.7 |
| Private for profit | 301 | 49.4 |
| Geographic location | ||
| Paris | 121 | 19.9 |
| North West | 102 | 16.7 |
| North East | 160 | 26.3 |
| South West | 85 | 14.0 |
| South East | 141 | 23.2 |
| Inpatient stays | N = 8,926,120 | % |
| Inpatient mortality | 73,477 | 0.8 |
| Year | ||
| 2007 | 1,545,068 | 17.3 |
| 2008 | 1,535,327 | 17.2 |
| 2009 | 1,493,460 | 16.7 |
| 2010 | 1,459,603 | 16.4 |
| 2011 | 1,452,632 | 16.3 |
| 2012 | 1,440,030 | 16.1 |
| Women | 4,648,989 | 52.1 |
| Age (years), mean (SD) | 58.2 (17.7) | - |
| No. different Elixhauser comorbidities, a mean (SD) | 0.8 (1.1) | - |
| Surgical procedure codes | ||
| Operation on the Nervous system | 267,287 | 3.0 |
| Operation on the Ear, Nose, Mouth and Pharynx | 481,417 | 5.4 |
| Operation on the Cardiovascular system | 1,396,807 | 15.6 |
| Operation on the Hematologic and Lymphatic system | 321,201 | 3.6 |
| Operation on the Respiratory system | 132,926 | 1.5 |
| Operation on the Digestive system | 859,637 | 9.6 |
| Operation on the Urinary system | 209,809 | 2.4 |
| Operation on the Genital organs | 986,981 | 11.1 |
| Operation on the Endocrine system | 274,791 | 3.1 |
| Operation on the Musculoskeletal system | 3,494,955 | 39.2 |
| Operation on the Integumentary system | 1,326,220 | 14.9 |
| Procedure complexity, mean (SD) | 364.8 (291.4) | - |
| Month | ||
| January | 783,138 | 8.8 |
| February | 798,006 | 8.9 |
| March | 848,363 | 9.5 |
| April | 771,396 | 8.6 |
| May | 732,360 | 8.2 |
| June | 765,809 | 8.6 |
| July | 664,904 | 7.4 |
| August | 468,758 | 5.3 |
| September | 737,604 | 8.3 |
| October | 860,629 | 9.6 |
| November | 762,169 | 8.5 |
| December | 732,984 | 8.2 |
a Elixhauser comorbidities include congestive heart failure, cardiac arrhythmias, valvular disease, pulmonary circulation disorders, peripheral vascular disorders, hypertension uncomplicated/complicated, paralysis, other neurological disorders, chronic pulmonary disease, diabetes uncomplicated/complicated, hypothyroidism, renal failure, liver disease, peptic ulcer disease excluding bleeding, AIDS/HIV, lymphoma, metastatic cancer, solid tumour without metastasis, rheumatoid arthritis/collagen vascular diseases, coagulopathy, obesity, weight loss, fluid and electrolyte disorders, blood loss anaemia, deficiency anaemia, alcohol abuse, drug abuse, psychoses, and depression.