Background
Methods
Study setting and agreement to participate
Survey Processes
Variable | Description and categories |
---|---|
Outcome variable
| |
Skin infection incidence rate (person-year) | For each child aged under seven years, data on presentations to the health centre for skin infections (scabies and/or bacterial infection) were collected through an audit of health centre records for the one year period preceding the survey. Any record in the clinical notes indicating a diagnosis of scabies, impetigo or infected skin sores was counted as an episode, except if the record was within seven days of an earlier diagnosis of the same condition. |
Primary explanatory variables
| |
Housing condition, materials and design
| |
Facilities for washing children not functioning | 1. For child <1 year: (i) bathroom basin, hot tap, cold tap, bench, door, electrical and general structure are all functioning, or (ii) kitchen sink, hot tap and cold tap all functioning. 2. For child aged 1 to <3 years: (i) laundry trough, hot tap, cold tap, shelf, electricity, floor drainage and general structure are all functioning, or (ii) the bathroom shower head, hot tap, cold tap, drainage, bench, electrical and general structure are all functioning. 3. For child aged 3 to less than 7 years: bathroom shower head, hot tap, cold tap, drainage, bench, door, electrical and general structure are all functioning. Facilities not functioning versus facilities functioning (reference). |
Facilities for washing clothes and bedding not functioning | 1. Laundry trough, hot tap, cold tap, shelf, electricity, floor drainage and general structure all functioning. Facilities not functioning versus facilities functioning (reference). |
Facilities for removing human faeces not functioning | 1. If child <1 year: toilet pan, cistern, water supply, drainage, bathroom basin and hot and cold taps are all functioning. 2. If child aged 1 to <3 years: child toilet equipment (e.g. potty – small plastic toilet), toilet pan, cistern, water supply, drainage, electricity, general structure, bathroom basin and hot and cold taps are all functioning. 3. If child aged 3 to less than 7 years: toilet door, electricity, general structure, toilet pan, cistern, water supply, drainage, bathroom basin, hot tap and cold tap are all functioning. Facilities not functioning versus facilities functioning (reference). |
Combined HLPs | Failed at least one of the three healthy living practices previously defined |
Concrete/other floor material (no tiles) | Observed by surveyor. The floor type for the main living areas (kitchen and living room) of dwellings were categorised according to (1) concrete, (2) tiles, (3) other, (4)concrete and tiles, (5) concrete and other, and (6) tiles and other. The variable was then dichotomised to reflect the contrast between dwellings that have concrete/other flooring versus those that have tiles (reference). |
Dwelling built pre 1980 | As reported by community housing office or experienced government housing program staff. Older dwellings (pre 1980) versus newer dwellings (reference). |
Secondary explanatory variables
| |
Community A | Community A versus Community B (reference). |
Hygiene condition of dwelling environment and immediate surrounds
| |
Internal contaminants present | Presence of obvious organic contaminants observed by surveyor in the dwelling (e.g. faecal contamination (disposable nappies), food scraps, etc.) versus no contaminants (reference). |
External contaminants present | Presence of obvious organic contaminants observed by surveyor on the sealed surrounds (i.e. veranda) of the dwelling versus no contaminants (reference). |
Household cleaning software
| |
Household cleaning equipment missing | Observed by surveyor. At least one of the broom, mop or bucket absent (as observed by the surveyor) versus dwellings with all items present (reference). |
No soap in dwelling | Observed by surveyor. No soap around the bathroom, kitchen or laundry sinks versus soap present (reference). |
Child and carer socio-demographic factors
| |
Child age less than 3 years | Reported by carer and date of birth verified against health centre audit (health centre records used as true age). Child less than 3 years versus child 3 to less than 7 years (reference). |
Child sex (male) | Reported by carer. Child sex male versus female (reference). |
Carer age | Reported by carer. Categorised into three dummy variables: carer less than 20 years, carer 20 to 34 years (reference), and carer 35 plus years. |
Low family income | Family income per week as reported by the primary carer. Low family income (less than median family income ($935) for the two communities) versus greater than median family income (reference). |
Carer highest education | Highest formal qualification as reported by the carer. Categorised to three dummy variables. Grades 11 and 12 (reference), grades 9 and 10, and grade 8 and below. |
Carer unemployed | Reported by carer. Employed refers to any employment including CDEP (a type of 'work-for-the-dole' scheme). Carer unemployed versus carer employed (reference). |
Household composition
| |
Four or more children aged less than 7 years in the dwelling | Number of children less than 7 years usually resident in the dwelling (at least 6 out of 12 months) as reported by householder and primary carer. Four or more children less than 7 years in dwelling versus less than 4 children (reference). |
Three carers' in dwelling | Reported by householder and carer. Only the main carer of each child was counted (i.e. variable refers to number of carers of different children). Three carers in dwelling versus one or two carers' in dwelling (reference). |
Crowding: Residents per bedroom | Number of residents (includes visitors) reported by householder and carer. Number of bedrooms based on dwelling survey. Categorised into three dummy variables. Two persons or less per bedroom (reference), greater than two to four or less persons per bedroom, and greater than 4 persons per bedroom. |
Child mobility (high) | Reported by carer whether child sleeps at another dwelling at least one night in ten (or 10%). Child mobility high versus low mobility (reference). |
Presence of a visitor in the dwelling | Reported by householder and carer. A visitor was defined as anyone who is not a usual resident who is currently staying at the dwelling for at least one week. Visitor(s) present versus no visitors (reference). |
Data analysis
Results
Community A | Community B | Community C | Total | |
---|---|---|---|---|
Population and housing
| ||||
Estimated number of children aged < 7 years | 135 | 54 | 23 | 212 |
Number of children < 7 years surveyed | 100 | 38 | 23 | 161 |
Estimated response rate |
74.1
|
70.4
|
100.0
|
75.9
|
Number of carers§
| 54 | 26 | 15 | 95 |
Number of residents¶
| 473 | 175 | 102 | 750 |
Number of usual residents | 420 | 157 | 87 | 664 |
Number of dwellings | 46 | 23 | 13 | 82 |
Number of bedrooms | 132 | 58 | 36 | 226 |
Mean no. of bedrooms per dwelling (SD) | 2.9 (0.5) | 2.5 (0.8) | 2.8 (0.8) | 2.8 (0.7) |
Mean no. of residents per bedroom (SD) | 3.6 (1.5) | 3.4 (1.6) | 2.7 (1.4) | 3.4 (1.5) |
Primary explanatory variables
| ||||
Number of dwellings (%)
|
n (%)
|
n (%)
|
n (%)
|
n (%)
|
Facilities not functioning to: | ||||
Wash children | 15 (32.6) | 1 (4.3) | 7 (53.8) | 23 (28.0) |
Wash clothes | 21 (45.7) | 5 (21.7) | 5 (38.5) | 31 (37.8) |
Remove faeces | 21 (45.7) | 7 (30.4) | 12 (92.3) | 40 (48.8) |
Combined healthy living practices | 29 (63.0) | 10 (43.5) | 12 (92.3) | 51 (62.2) |
Concrete/other floor material | 19 (41.3) | 1 (4.3) | 11 (91.7) | 31 (37.8) |
Dwelling built pre 1980 | 8 (17.4) | 8 (34.8) | 5 (38.5) | 21 (25.6) |
Community A (NA = 100) | Community B (NB = 38) | All children (N = 138) | Univariate incidence rate ratios | |
---|---|---|---|---|
n (%) | n (%) | n (%) | IRR (95% CI) | |
No skin infections | 41 (41.0) | 13 (34.1) | 54 (39.1) | na |
2 or more skin infections | 37 (37.0) | 10 (26.3) | 47 (34.0) | na |
5 or more skin infections | 12 (12.0) | 2 (5.3) | 14 (10.0) | na |
Total number of skin infections | 162 | 50 | 212 | na |
Median skin infections per child (range) | 1 (0 – 8) | 1 (0 – 9) | 1 (0 – 9) | na |
Skin incidence rate (person-years) | 1.84 | 1.47 | 1.74 | na |
Primary explanatory variables
| ||||
Dwelling facilities required to: | ||||
- wash children not functioning | 35 (35.0) | 3 (7.9) ** | 38 (27.5) | 1.23 (0.75 – 1.99) |
- wash clothes not functioning | 51 (51.0) | 10 (26.3) * | 61 (44.2) | 1.40 (0.83 – 2.36) |
- remove human faeces not functioning | 42 (42.0) | 8 (21.1) * | 50 (36.2) | 1.68 (0.99 – 2.87) |
Combined HLPs | 64 (64.0) | 15 (39.5) * | 79 (57.2) |
1.96 (1.25 – 3.07) |
Concrete/other floor material (no tiles) | 53 (53.0) | 2 (5.3) ** | 98 (71.0) | 1.26 (0.74 – 2.14) |
Dwelling built pre 1980 | 15 (15.0) | 14 (36.8) ** | 29 (21.0) | 1.23 (0.68 – 2.25) |
Secondary explanatory variables
| ||||
Community A | - | - | 100 (72.5) | 1.27 (0.74 – 2.20) |
Community B (reference category) | - | - | 38 (27.5) | 1.00 |
Health software
| ||||
Household cleaning equipment missing | 79 (79.0) | 6 (15.8) ** | 87 (63.0) | 1.59 (0.90 – 2.80) |
No soap in bathroom | 57 (57.0) | 5 (13.2) ** | 62 (44.9) | 1.23 (0.72 – 2.09) |
Contaminants
| ||||
Internal contaminants present | 79 (79.0) | 35 (92.1) | 114 (82.6) | 0.57 (0.28 – 1.14) |
External contaminants present | 82 (82.0) | 36 (94.7) | 118 (85.5) | 1.66 (0.83 – 3.31) |
Child and carer socio-demographic factors
| ||||
Child less than 3 years | 49 (49.0) | 19 (50.0) | 68 (49.3) |
1.95 (1.40 – 2.72) |
Child sex (male) | 52 (52.0) | 17 (44.7) | 69 (50.0) | 0.86 (0.52 – 1.43) |
Child mobility (high) | 7 (7.0) | 5 (13.2) | 12 (8.7) | 0.78 (0.42 – 1.47) |
Carer age < 20 years | 13 (13.0) | 3 (7.9) | 16 (11.6) |
3.20 (2.18 – 4.71) |
Carer 20 years to LT 35 years | 77 (77.0) | 29 (76.3) | 106 (76.8) | 1.00 |
Carer 35 years or more | 10 (10.0) | 6 (15.8) | 16 (11.6) |
1.79 (1.06 – 3.04) |
Low family income (≤ $935 or median) | 58 (58.0) | 12 (31.6) ** | 70 (51.1) |
2.10 (1.30 – 3.40) |
Carer unemployed | 76 (76.0) | 9 (23.7) ** | 85 (61.6) | 1.25 (0.78 – 1.99) |
Carer highest level of education | ||||
Years 11 or 12 | 11 (11.0) | 6 (15.8) | 17 (12.3) | 1.00 |
Years 9 or 10 | 23 (23.0) | 21 (55.3) ** | 44 (31.9) | 1.26 (0.74 – 2.16) |
Year 8 or below | 66 (66.0) | 11 (29.0) ** | 77 (55.8) |
1.92 (1.19 – 3.12) |
Household composition variables
| ||||
Four or more children < 7 yrs in dwelling | 29 (29.0) | 8 (21.1) | 37 (26.8) | 1.54 (0.84 – 2.82) |
Three carers in dwelling | 12 (12.0) | 4 (10.5) | 16 (11.6) |
2.26 (1.24 – 4.13) |
Visitors present in dwelling | 20 (20.0) | 12 (31.6) | 31 (22.6) | 0.79 (0.49 – 1.28) |
Residents per bedroom | ||||
Lowest (1.33–2.00) | 9 (9.0) | 10 (26.3) * | 19 (13.8) | 1.00 |
Middle (2.33–4.00) | 57 (57.0) | 16 (42.1) | 73 (52.9) | 1.51 (0.59 – 3.86) |
Highest (4.33–8.33) | 34 (34.0) | 12 (31.6) | 46 (33.3) | 1.11 (0.44 – 2.79) |
Model 1 | Model 2 | Model 3 | Model 4 | |
---|---|---|---|---|
IRR (95% CI) | IRR (95% CI) | IRR (95% CI) | IRR (95% CI) | |
Main effects
| ||||
Facilities for removing human faeces not functioning | 1.28 (0.88–1.85) | na | na | 2.03 (1.34–3.06) |
Combined HLPs | na | 1.37 (0.92–2.03) | na | na |
Dwelling built pre 19801,2,3
| 0.76 (0.36–1.61) | 0.64 (0.32–1.30) | 1.16 (0.51–2.60) | na |
Concrete/other floor material1
| 2.27 (0.67–7.67) | a | a | na |
Household cleaning equipment missing3
| a | a | 1.82 (1.18–2.81) | a |
Internal contaminants present | a | a | a | 0.67 (0.45–1.00) |
External contaminants present | a | a | a | 2.27 (1.28–4.03) |
Child age | ||||
Less than 3 years1,2,3
| 1.57 (1.06–2.33) | 1.46 (0.98–2.18) | 1.54 (1.04–2.29) | 1.63 (1.17–2.28) |
3 to less than 7 years | 1.00 | 1.00 | 1.00 | 1.00 |
Carer age | ||||
Less than 20 years | 2.29 (1.60–3.26) | 2.36 (1.54–3.63) | 2.19 (1.45–3.29) | a |
20 to 34 years | 1.00 | 1.00 | 1.00 | a |
35 years or more | 2.41 (1.57–3.71) | 2.30 (1.56–3.39) | 2.38 (1.64–3.44) | a |
Three carers in dwelling4
| a | a | a | 0.63 (0.21–1.90) |
4 or more children under 7 years | 2.55 (1.70–3.81) | 1.95 (1.26–3.02) | 1.89 (1.23–2.92) | a |
Child mobile | 1.39 (0.88–2.20) | 1.46 (0.90–2.36) | 1.57 (0.98–2.50) | a |
Residence per bedroom | ||||
Lowest (≤ 2 per bedroom) | 1.00 | 1.00 | 1.00 | a |
Middle (2 to ≤ 4 per bedroom)1
| 2.22 (0.89–5.52) | 1.35 (0.72–2.52) | 1.25 (0.70–2.26) | a |
Highest (4 to 8.33 per bedroom)1
| 1.61 (0.61–4.21) | 1.81 (0.90–3.63) | 1.54 (0.81–2.93) | a |
Carers education | ||||
Grade 11 and 12 | a | a | a | 1.00 |
Grade 9 and 10 | a | a | a | 0.92 (0.53–1.61) |
Grade 8 and below | a | a | a | 1.70 (1.02–2.84) |
Low family income (≤ $935) | 2.21 (1.53–3.20) | 1.84 (1.25–2.69) | 1.78 (1.24–2.57) | 1.62 (1.10–2.37) |
Carer unemployed4
| 0.73 (0.52–1.03) | a | a | 0.53 (0.35–0.82) |
Interactions
| ||||
Child less than 3 years × dwelling built pre-1980 | 3.04 (1.52–6.08) | 3.63 (1.74–7.57) | 4.14 (1.95–8.80) | na |
Cleaning equipment missing × dwelling built pre-1980 | a | a | 0.36 (0.17–0.74) | na |
Concrete/other floor material × middle level crowding | 0.35 (0.09–1.30) | a | a | na |
Concrete/other floor material × highest level crowding | 1.11 (0.29–4.26) | a | a | na |
Carer unemployed × three or more carer's in dwelling | a | a | a | 6.19 (1.93–19.84) |
Log pseudo-likelihood | -196.298 | -201.777 | -199.553 | -203.606 |
Model: Pseudo R
2
| 15.1% | 12.7% | 12.7% | 11.9% |
Model/Significant contrasts for interaction terms | Incidence rate ratio (95% CI) |
---|---|
Model 1
| |
Young children (<3 years) & old dwelling (pre-1980) versus young children & newer dwellings | 2.30 (1.57 – 3.38) |
Young children (<3 years) & old dwelling (pre-1980) versus old children & newer dwellings | 3.62 (2.32 – 5.64) |
Young children (<3 years) & old dwelling (pre-1980) versus old children & old dwellings | 4.79 (2.59 – 8.86) |
Young children (<3 years) & newer dwelling (post-1980) versus old children & newer dwellings | 1.57 (1.06 – 2.33) |
Young children (<3 years) & newer dwelling (post-1980) versus old children & old dwellings | 2.08 (0.98 – 4.42) |
High level of crowding & concrete/other floor versus high crowding & tiled floor | 2.52 (1.38 – 4.59) |
High level of crowding & concrete/other floor versus middle crowding & tiled floor | 11.56 (1.50 – 89.3) |
High level of crowding & concrete/other floor versus low crowding & tiled floor | 4.05 (1.50 – 10.9) |
Model 2
| |
Young children (<3 years) & old dwelling (pre-1980) versus young children & newer dwellings | 2.33 (1.54 – 3.53) |
Young children (<3 years) & old dwelling (pre-1980) versus old children & newer dwellings | 3.41 (2.24 – 5.21) |
Young children (<3 years) & old dwelling (pre-1980) versus old children & old dwellings | 5.30 (2.83 – 9.94) |
Young children (<3 years) & newer dwelling (post-1980) versus old children & newer dwellings | 1.46 (0.98 – 2.18) |
Young children (<3 years) & newer dwelling (post-1980) versus old children & old dwellings | 2.27 (1.12 – 4.61) |
Model 3
| |
Young children (<3 years) & old dwelling (pre-1980) versus young children & newer dwellings | 4.79 (2.48 – 9.28) |
Young children (<3 years) & old dwelling (pre-1980) versus old children & newer dwellings | 7.40 (3.52 – 15.6) |
Young children (<3 years) & old dwelling (pre-1980) versus old children & old dwellings | 6.39 (3.30 – 12.4) |
Young children (<3 years) & newer dwelling (post-1980) versus old children & newer dwellings | 1.54 (1.04 – 2.29) |
Cleaning equip§ missing & newer dwelling (post-1980) versus equipment missing & old dwelling | 2.43 (1.16 – 5.10) |
Cleaning equip§ missing & newer dwelling (post-1980) versus equip§ not missing & newer dwelling | 1.82 (1.18 – 2.81) |
Model 4
| |
Carer unemployed & 3 carers in dwelling versus carer unemployed & 1 or 2 carers in dwelling | 3.90 (2.45 – 6.21) |
Carer unemployed & 3 carers in dwelling versus carer employed & 1 or 2 carers in dwelling | 2.09 (1.31 – 3.32) |
Carer unemployed & 3 carers in dwelling versus carer employed & 3 carers in dwelling | 3.31 (1.07 – 10.2) |
Carer unemployed & 1 or 2 carers in dwelling versus carer employed & 1 or 2 carers in dwelling | 0.54 (0.35 – 0.82) |