Table 2 Agreement between answers to repeat questionnaires at 3-month intervals by parents of 1-year-old children (n = 413)
+++−−+−−POPposPnegκ (95% CI)
Wheeze
    Wheeze ever*95212527288.980.592.20.73 (0.65–0.80)
    Wheeze last 12 months*83272228188.177.292.00.69 (0.61–0.77)
    Wheeze without cold2591036995.472.597.50.70 (0.57–0.83)
    Shortness of breath39182133590.666.794.50.61 (0.50–0.72)
Cough
    Cough without cold92384623779.768.784.90.54 (0.45–0.62)
    Cough at night last 12 months*43433828980.451.587.70.39 (0.28–0.50)
Diagnoses
    Diagnosis of asthma3181136395.476.597.40.74 (0.63–0.85)
    Eczema last 12 months*120283323285.279.788.40.68 (0.61–0.76)
Ears, nose and throat symptoms
    Chronic rhinitis*66583925076.557.683.80.42 (0.32–0.51)
Snoring176543914477.579.175.60.55 (0.47–0.63)
    Repeated otitis media125323522183.878.986.80.66 (0.58–0.73)
Treatment
    Inhaled bronchodilators4381534794.478.996.80.76 (0.66–0.85)
    Inhaled corticosteroids191838597.880.998.80.80 (0.67–0.93)
Family history
    Paternal wheeze/asthma6912632695.688.597.30.86 (0.79–0.92)
    Maternal wheeze/asthma6113933094.784.796.80.82 (0.74–0.89)
Household and environment
    Maternal smoking795632397.393.598.30.92 (0.87–0.97)
    Other person smoking7951631394.988.396.80.85 (0.79–0.91)
    Mother smoking during pregnancy612434698.595.399.10.95 (0.90–0.99)
    Cooking with gas299789996.497.693.00.91 (0.86–0.95)
    Central heating388281597.698.775.00.74 (0.58–0.89)
    Pets1697723096.696.097.00.93 (0.90–0.97)
    Attended nursery95202027890.382.693.30.76 (0.69–0.83)
    Breastfed2643414298.398.797.60.96 (0.94–0.99)
  • ++ positive on baseline and repeat questionnaires, +− positive on baseline questionnaire only, −+ positive on repeat questionnaire only, −− negative on baseline and repeat questionnaires.

  • Pneg proportion of observed negative agreement; PO, proportion of observed total agreement; Ppos proportion of observed positive agreement; 95% CI, 95% confidence interval of κ.

  • Level of agreement indicated by κ: ⩽0.4 poor, 0.41–0.60 moderate, 0.61–0.80 good, >0.8 excellent.

  • *Questions from ISAAC core questionnaire.6