Table 1.
Incidence rates of hospitalization for bronchiolitis in the first 18 months of age in premature infants, Rome, Italy, 2000-2006
|
Person years (PY) |
Cases |
Rate (per 100 PY) |
95% CI | |
| Age (months) | ||||
| [0 -- 6] | 986 | 88 | 8.93 | 7.24 -11.00 |
| (6 - 12] | 1005 | 42 | 4.18 | 3.09 -5.65 |
| (12 - 18] | 921 | 7 | 0.76 | 0.36 -1.59 |
| Calendar month | ||||
| January | 223 | 25 | 11.20 | 7.57 -16.57 |
| February | 226 | 24 | 10.64 | 7.13 -15.87 |
| March | 227 | 14 | 6.18 | 3.66 -10.43 |
| April | 229 | 12 | 5.23 | 2.97 -9.21 |
| May | 235 | 4 | 1.70 | 0.64 -4.54 |
| June | 238 | 3 | 1.26 | 0.41 -3.90 |
| July | 245 | 2 | 0.82 | 0.20 -3.27 |
| August | 251 | 3 | 1.20 | 0.39 -3.71 |
| September | 254 | 3 | 1.18 | 0.38 -3.66 |
| October | 257 | 12 | 4.67 | 2.65 -8.22 |
| November | 262 | 18 | 6.88 | 4.33 -10.91 |
| December | 266 | 17 | 6.39 | 3.98 -10.29 |
| Year of observation | ||||
| 2000 | 138 | 7 | 5.07 | 2.42 -10.63 |
| 2001 | 399 | 17 | 4.26 | 2.65 -6.85 |
| 2002 | 427 | 22 | 5.15 | 3.39 -7.82 |
| 2003 | 436 | 30 | 6.88 | 4.81 -9.84 |
| 2004 | 503 | 18 | 3.58 | 2.25 -5.68 |
| 2005 | 527 | 23 | 4.36 | 2.90 -6.56 |
| 2006 | 481 | 20 | 4.16 | 2.68 -6.44 |
| Total | 2912 | 137 | 4.70 | 3.98 -5.56 |