Table 1. Data sources used to estimate probability of exposure to adverse household conditions in New Zealand.

Risk factor	Source	Study type and population	Measure	Proportion of people exposed
Household crowding	New Zealand Ministry of Health, 201415	2013 Census of entire New Zealand population. Data on crowding covered 3 931 041 people	Proportion of population living in crowded conditions. A household was considered crowded if there was a one-bedroom deficit	10.1% (95% CI: 10.1–10.2%) all ages; 15.4% of children aged 0–4 years
Cold housing	Statistics New Zealand, 20153	2014 General Social Survey of a representative survey of New Zealanders aged ≥ 15 years. 8795 individuals answered the personal questionnaire	Proportion of people surveyed who reported their home was always or often colder than they would like	21.2% (95% CI: 20.0–22.3%)
Damp or mouldy housing	Statistics New Zealand, 20153	2014 General Social Survey of a representative survey of New Zealanders aged ≥ 15 years. 8795 individuals answered the personal questionnaire	Proportion of people surveyed who had a minor or major problem with dampness or mould in their home. Housing conditions were self-reported, with the presence of dampness and mould indicated by sight or smell (such as visible mould or dampness, mouldy or musty odour)	31.8% (95% CI: 29.7–33.8%)
Injury hazards leading to falls	Keall MD, et al., 201516	Randomized controlled trial of 842 New Zealand households, 2009–2013. Households were randomly assigned to have either immediate home modifications done to prevent falls or to wait 3 years (436 in the treatment group and 406 in the control group)	Proportion of homes in need of repair to prevent falls among a sample of houses typical of New Zealand housing. 94% (382/406) of homes needed at least one modification	26% of home injuries caused by falls needing medical treatment were preventable by home modifications

CI: confidence interval.