Demographic and other baseline characteristics of the control and intervention groups stratified for sex
| Total | Males | Females | ||||
| Intervention | Control | Intervention | Control | Intervention | Control | |
| Subjects n | 222 | 221 | 118 | 111 | 104 | 110 |
| Age yrs mother | 30.9±3.8 | 31.0±3.6 | 31.1±4.1 | 30.7±3.7 | 30.7±3.5 | 31.3±3.4 |
| Low education# mother | 2 (14.5) | 20 (9.0) | 17 (14.4) | 12 (10.8) | 15 (14.6) | 8 (7.3) |
| Family history of asthma | ||||||
| Father | 84 (38.0) | 80 (36.5) | 48 (41.0) | 36 (32.7) | 36 (34.6) | 44 (40.4) |
| Mother | 118 (53.4) | 111 (50.7) | 60 (51.3) | 59 (53.6) | 58 (55.8) | 52 (47.7) |
| Siblings | 83 (60.1) | 95 (68.3) | 43 (59.7) | 46 (65.7) | 40 (60.6) | 49 (71.0) |
| Birth weight | 3387 (528) | 3475 (583) | 3438 (569) | 3492 (624) | 3329 (474) | 3465 (538) |
| Pregnancy duration weeks | 39.7 (1.7) | 39.7 (1.6) | 39.6 (1.8) | 39.7 (1.8) | 39.7 (1.4) | 39.7 (1.6) |
| Delivery at home | 71 (32.0) | 81 (36.7) | 34 (28.8) | 46 (41.8) | 37 (35.6) | 35 (31.8) |
| Uncomplicated delivery | 172 (77.8) | 168 (76.0) | 85 (72.6) | 81 (73.6) | 87 (83.7) | 86 (78.2) |
| Age house ≤20 yrs | 101 (47.4) | 120 (54.8) | 52 (45.6) | 59 (53.6) | 49 (49.5) | 61 (56.0) |
| First-born | 87 (39.2) | 85 (38.3) | 46 (39.0) | 43 (38.7) | 41 (39.4) | 41 (37.3) |
| Day-care attendance | 78 (38.2) | 70 (36.6) | 41 (36.9) | 34 (36.2) | 37 (39.8) | 36 (37.1) |
| Born in spring/summer | 108 (49.5) | 112 (50.5) | 54 (45.8) | 55 (49.5) | 53 (51.0) | 59 (53.6) |
| Exposure at baseline | ||||||
| Der p1 ng·m−2 (IQR)¶ | 148 (1421)+ | 79 (474)*** | 136 (1670)+ | 88 (484)** | 193 (1617)+ | 65 (380)** |
| Fel d1 ng·m−2 (IQR)¶ | 94 (244) | 73 (288) | 96 (285) | 83 (362) | 96 (288) | 69 (278) |
| Can f1 ng·m−2 (IQR)¶ | 34 (274) | 39 (258) | 26 (356) | 40 (533) | 42 (255) | 42 (184) |
| Smoking mother | 28 (14.1) | 32 (15.7) | 16 (15.1) | 22 (22.0) | 12 (12.9) | 10 (9.6) |
| Smoking father | 46 (24.1) | 46 (23.5) | 24 (24.0) | 28 (29.2) | 22 (24.2) | 18 (18.0) |
| Presence of cat or dog | 62 (31.5) | 71 (34.9) | 35 (32.7) | 39 (39) | 27 (29.3) | 32 (31.7) |
Data are presented as n (%) or mean±sd, unless otherwise stated. #: only primary school; ¶: calculated as the mean level of the median amount of the specific allergen levels in dust from parental and infant mattresses and living room floor. **: p<0.01; ***: p<0.001; +: statistically significant, intervention versus control group.