Table 2.
Test–retest reliability for scales and items for the polonium 210, carbon monoxide or anthrax versions of the questionnaire (Study 2).
| Scale (number of items) | Intra-class correlation coefficient (for scales: ICC2 (A,1)) or weighted kappa (for single item) with 95% confidence interval in parentheses |
|---|---|
| Mystery (4) | 0.77 (0.74–0.79) |
| Serious health effects (6) | 0.71 (0.67–0.74) |
| Hidden health effects (5) | 0.68 (0.64–0.71) |
| Easy to spot exposure (3) | 0.64 (0.60–0.67) |
| Difficult to discriminate symptoms (3) | 0.53 (0.48–0.58) |
| The existence of at-risk groups (4) | 0.51 (0.46–0.55) |
| I think that X can affect your health if | |
| You breathe in air that contains X (1) | 0.42 (0.37–0.47) |
| You eat food that has been contaminated by X and has not been cooked (1) | 0.58 (0.54–0.62) |
| You eat food that has been contaminated by X and has been cooked (1) | 0.52 (0.49–0.56) |
| You touch X but do not breathe it in or put it near your mouth (1) | 0.49 (0.45–0.54) |
| You are coughed or sneezed on by a person who is currently ill because of X (1) | 0.54 (0.51–0.58) |
| You come within 1 m (3 ft) of polonium 210, but do not breathe it in or touch ita (1) | 0.43 (0.35–0.50) |
| How long does it usually take for the first signs of ill health to start to appear? (1) | 0.47 (0.42–0.52) |
a
Item only asked in polonium 210 version of the questionnaire.