Table 1 Classification Tree Variables.

Physical Contact

1 = 'yes';

2 = 'no'

touching

Location

1 = 'home';

2 = 'work';

3 = 'school',

4 = 'transport';

5 = 'leisure';

6 = 'other-multiple'

location

Frequency

1 = 'daily';

2 = 'weekly';

3 = 'monthly';

4 = 'few times a year';

5 = 'first time'

frequency

Duration

1 = '0–5 min';

2 = '5–15 min';

3 = '15 min – 1 hour';

4 = '1–4 hours';

5 = '> 4 hours'

duration

Age Contact

Continuous

agecon

Gender Contact

1 = 'male';

2 = 'female'

gencon

Age Participant

Continuous

agepar

Gender Participant

1 = 'male';

2 = 'female'

genpar

Occupation Participant

1 = 'working';

2 = 'retired';

3 = 'at home';

4 = 'unemployed/job seeking';

5 = 'in education';

6 = 'other'

occpar

Household Size Participant

Household Size

(including participant)

hhsize

Region

Brss = 'Brussels'

WlsG = 'Walloon region'

VlsG = 'Flanders'

region

Day of the Week

0 = 'Sunday';

1 = 'Monday';

2 = 'Tuesday';

3 = 'Wednesday';

4 = 'Thursday';

5 = 'Friday';

6 = 'Saturday'

dayofweek

Holiday Period

0 = 'no holiday period'

1 = 'holiday period';

holiday