Table 1.
Summary results from birth cohort studies
| Study | Design, age, numbers | Cat/dog ownership | Definition of exposure | Outcome measures | Association between cat/dog exposure and AS |
|---|---|---|---|---|---|
| Hagendorens et al51 | UBC 1 year n = 810 |
C: 53% D: 35% |
C, D During first year of life |
Q, IgE | Sens to C: NR Sens to D: NR AS: NA |
| Custovic et al46 | UBC 1 year n = 517 |
C: 15% D: 14% |
C, D ownership | Q spt, IgE | Sens to C: increased with C if positive FH Sens to D: NA AS: NR |
| Arshad et al42,43 | UBC 4 years n = 1218 |
C: 39% D: 30% |
C, D current | Spt, Q | Sens to C: NA Sens to D: NA AS: NR |
| Torrent et al47 | UBC 4 years n = 1019 |
C: 16.7% in first year D: NR |
Fel d1, Can f1 at 3 months | IgE Q |
Sens to C: increased with increasing Fel d1 exposure Sens to D: NR AS: NR |
| Perzanowski et al41 | UBC Age 2 (n = 323), 3 (n = 336) and 5 (n = 242) |
C: 10%–25% D: NR |
Fel d1, C | IgE, IgG | Sens to C: increased in C owners by age 2, NA by age 5 years Sens to D: AS: NR |
| Ownby et al43 | UBC 6–7 yrs n = 474 |
C: 32% in infancy D: 45% in infancy |
C, D, current infancy, Fel d1 | Spt, IgE, BHR | Sens to C: NA Sens to D: decreased with D in infancy AS: decreased with 2 or more D or C |
| Remes et al44 | UBC 13 years n = 1076 (n = 613 with IgE) |
C: 22% D: 30% |
C, D indoors infancy | Spt (but not to D), Q | Sens to C: NA at 11 years Sens to D: NR AS: NA |
| Gern et al38 | HRBC 1 year n = 285 |
C: 29% D: 35% |
C, D ownership | Q, IgE | Sens to C: NR at 1 year, NA at 3 years Sens to D: NR at 1 year, NA at 3 years AS: Reduced with D at 1 year, NA at 3 years; NA for C at 1 or 3 years |
| Brussee et al45 | SBC 4 years, 8 years (high- and low-risk only) n = 1248 with IgE at 8 years |
C: 34% D: 16% |
Fel d1, Can f1 at 3 months | IgE Q |
Sens to C: increased with increasing Fel d1 exposure if mother nonatopic at 4 years; NA at 8 years, Sens to D: NA at 4 years or 8 years AS: NR at 4 years; reduced with dog at 8 years |
| Munir et al3 | HRBC 5 years n = 86 |
C: 8% D: 9% |
C, D, current, peak Fel d1, Can f1 | Spt | Sens to C: NA with Fel d1 levels or C ownership Sens to D: Too few sens to D to comment AS: NR |
| Burr et al50 | HRBC 7 years n = 440 |
C: NR D: NR |
C, D current | Spt, IgE, Q | Sens to C: NR Sens to D: NR AS: Reduced IgE in C or D in infancy. NA for spt |
| Lau9,48 | SBC 7 years n = 939 |
C: NR D: NR Levels of Fel d1 generally low |
C current Fel d1 |
IgE and IgG to cat, Q | Sens to C: increased with higher Fel d1 levels at 3 and 7 years; by age 10 years NA Sens to D: NR AS: NR |
Abbreviations: C, cat; D, dog, BC, birth cohort; S, selected; U, unselected; HR, high risk; Q, questionnaire; NR, not reported; NA, no association; FH, family history; spt, skin prick test; IgE, specific IgE; AS, allergic sensitization (≥1 allergens); UBC, unselected birth cohort.