Table 3.
Intraclass correlations (with 95% confidence intervals) for unadjusted and adjusted FEV1, VC and DLco in a Swedish twin sample by sex and zygosity status.
| Men | Women | OS | |||
| MZ (n = 28) | DZ (n = 14) | MZ (n = 65) | DZ (n = 27) | (n = 42) | |
| VC | |||||
| Unadjusted | 0.57(0.26;0.78) | 0.41(-0.16;0.77) | 0.67(0.50;0.78) | 0.18(-0.21;0.53) | 0.23(-0.08;0.50) |
| Adj. PY | 0.49(0.15;0.73) | 0.29(-0.29;0.71) | 0.67(0.50;0.78) | 0.28(-0.12;0.59) | 0.25(-0.06;0.52) |
| Adj. PY, symptoms | 0.36(-0.01;0.65) | 0.18(-0.39;0.65) | 0.66(0.50;0.78) | 0.26(-0.14;0.58) | 0.24(-0.07;0.51) |
| FEV1 | |||||
| Unadjusted | 0.28(-0.10;0.59) | 0.42(-0.14;0.78) | 0.67(0.50;0.78) | 0.32(-0.07;0.62) | -0.07(-0.37;0.24) |
| Adj. PY | 0.27(-0.12;0.58) | 0.25(-0.33;0.69) | 0.66(0.50;0.78) | 0.39(0.01;0.67) | -0.01(-0.31;0.30) |
| Adj. PY, symptoms | 0.18(0.21-0.52) | 0.18(-0.39;0.65) | 0.65(0.48;0.77) | 0.32(-0.06;0.63) | -0.09(-0.38;0.22) |
| DLCO | |||||
| Unadjusted | 0.58(0.27;0.79) | 0.65(0.21;0.87) | 0.46(0.24;0.63) | 0.06(-0.35;0.44) | 0.35(0.04;0.60) |
| Adj. PY | 0.37(-0.00;0.65) | 0.23(-0.32;0.67) | 0.41(0.19;0.60) | 0.01(-0.39;0.40) | 0.29(-0.03;0.56) |
| Adj. PY, symptoms | 0.38(0.00;0.66) | 0.29(-0.26;0.70) | 0.41(0.17;0.58) | 0.02(-0.38;0.41) | 0.29(-0.03;0.56) |
1 n pairs MZ male = 28, DZ male = 15, MZ female = 66, DZ female = 25, OS = 39. PY= pack years