Abstract
Objective
To evaluate the effects of a Habitat for Humanity housing improvement programme in northern Malawi on the prevalence of childhood illnesses.
Design
Household based cross sectional study.
Setting
Rural communities centred near the small northern Malawi town of Ekwendeni.
Subjects
318 children under 5 years old.
Main outcome measures
Prevalence of respiratory, gastrointestinal, and malarial infections according to maternal recall, laboratory, or clinical data.
Results
Children living in improved homes were less likely to have respiratory, gastrointestinal, or malarial illnesses (odds ratio 0.56, 95% confidence interval 0.35 to 0.91) after confounding factors were controlled for. The reductions in individual diseases were not significant.
Conclusion
Improved housing significantly reduced the burden of disease among children under 5 years old.
What is already known on this topic
Poor quality housing is generally accepted as an important contributor to ill health
Few designed studies have quantified the impact of improved housing on health in the developing world
What this study adds
Improved housing reduced the odds of respiratory infection, gastrointestinal illness, or malaria by 44% in children under 5 years old
The reductions in individual illnesses were not significant
Housing development programmes are an important component of efforts to improve global health
Introduction
Poor quality housing is generally accepted to be an important contributor to ill health.1 Rates of disease have been associated with the quality and specific attributes of a house as well as the conditions that those qualities impose.2–11
Although the importance of housing for health is recognised,1,12,13 few well designed studies have quantified this impact, especially in the developing world. The objective of this study was to assess the impact on children's health of a housing improvement project in rural Malawi. We examined the effect on illness of living in improved housing compared with living in traditional housing.
Participants and methods
The study was conducted in collaboration with Ekwendeni Hospital, Homeless International UK, and Habitat for Humanity International in the town of Ekwendeni, Malawi. Traditional houses in the area are constructed of mud brick walls with thatch roofing, hard packed mud floors, and possibly a pit latrine. Houses are usually about 25 m2 and consist of two or three rooms. Houses constructed under the Habitat for Humanity programme in Ekwendeni have fired mud bricks, tile roofing, concrete foundation, and a pit latrine. Habitat houses have a mean size of 30 m2 and three rooms. The cost of a habitat house at the time of the study was about $550 (£370), offset by a 10 year no interest loan. Habitat houses were built next to or replaced the traditional house of the intended owner and were non-systematically dispersed throughout the communities among traditional houses.
Participants in the habitat programme were selected by a village habitat committee. Applicants had to be unable to provide adequate housing for themselves because of financial, social, or physical reasons and to have shown their commitment to the programme by spending a standardised amount of time helping to build another applicant's house.
Sample
We used data from two surveys conducted in March and August 1997. Households for the first survey were randomly selected from a list of about 300 habitat homes built at that time. Households for the second survey were selected from the same list, but houses surveyed in March were excluded. At enrolment, we asked permission to complete the survey, collect water samples from the household storage container and water source to test for coliforms (Hach Bromcresol purple broth and broth with methylumbelliferyl-β-D-glucuronide presence or absence method), collect blood from the finger of children younger than 5 years, and give a medical examination. Once we had collected data from the habitat house, we obtained data from the closest traditional house.
Instrument and measures
We used the illness recall method to assess the health of children under 5 years. In the first survey mothers reported symptoms experienced during the past month. In the second survey they were asked to report symptoms in the past two weeks. Analyses stratified by recall period found that trends were consistent across the two surveys so we combined the data. All children were screened for malaria by blood film examination and examined by a doctor to detect palpable spleens.14
Analysis of data
We compared habitat and traditional households with bivariate analyses using EpiInfo version 6.0. We then used the Genmod procedure to fit generalised linear models on correlated data using SAS for Windows (version 6.11). The Genmod procedure fits models using maximum likelihood estimation, and we used it to account for some households having more than one child, to adjust for potential confounding factors, and to test for interactions.
Results
Table 1 shows the numbers of houses included in each survey. We found no significant differences in socioeconomic and demographic variables between the habitat and traditional houses (table 2). Overall, the comparability of the non-housing socioeconomic characteristics in the two groups suggests that any differences between the two groups are likely to be due to differences in housing.
Table 1.
Construction of analytical dataset
| Survey | No of houses (No of children)
|
Total | |
|---|---|---|---|
| Habitat | Traditional | ||
| March: | |||
| Houses surveyed | 85 | 83 | 168 |
| Houses with children <5 years | 63 (97) | 74 (114) | 137 (211) |
| August: | |||
| Houses surveyed | 60 | 61 | 121 |
| Houses with children <5 years* | 39 (52) | 47 (70) | 86 (122) |
| Total houses with children <5 and complete data | 98 (143) | 114 (175) | 212 (318) |
Slide smears were unusable for 6 children in 4 habitat homes and 9 children in 7 traditional homes.
Table 2.
Comparison of socioeconomic and housing characteristics in two groups. Values are numbers (percentages) of households unless stated otherwise
| Variable | Habitat house (n=98) | Traditional house (n=114) | P value |
|---|---|---|---|
| Socioeconomic (responses from head of household) | |||
| Education*: | |||
| Primary (age 6-13) | 63 (64) | 73 (64) | 0.80 |
| Secondary (age 14-17) | 22 (22) | 26 (23) | |
| Able to read and write | 91 (93) | 105 (92) | 0.94 |
| Work status: | |||
| Farmer | 58 (59) | 71 (62) | 0.68 |
| Wage earner | 40 (41) | 43 (38) | |
| Land ownership: | |||
| Yes | 94 (96) | 103 (91) | 0.17 |
| Median area of land owned (acres) | 2.0 | 2.0 | 0.63 |
| Household characteristics | |||
| Mean (SD) years in house | 2.5 (1.8) | 5.9 (6.0) | 0.009 |
| Mean (SD) No of inhabitants | 6.07 (1.9) | 5.5 (2.0) | 0.22 |
| Mean (SD) No of children <5 years | 1.5 (0.7) | 1.5 (0.7) | 0.45 |
| Drinking water source: | |||
| Safe† | 38 (39) | 52 (46) | 0.32 |
| Unsafe‡ | 60 (61) | 62 (54) | |
| Disposal of excreta: | |||
| Bush or open field | 4 (4) | 9 (8) | <0.0001 |
| Communal pit latrine | 35 (36) | 62 (55) | |
| Private latrine | 59 (60) | 43 (38) | |
Some people had no education. †Protected well, borehole, or piped. ‡River, lake, pool, or unprotected well.
Table 3 shows the proportion of children under 5 years with various illnesses. The percentage of children with any or each of the three illnesses is lower in the habitat houses than the traditional houses.
Table 3.
Numbers (percentages) of children in habitat and traditional houses with various illnesses in past four weeks for March survey and past two weeks for August survey
| Habitat | Traditional | Total | |
|---|---|---|---|
| March survey: | 97 children | 114 children | |
| Any illness* | 37 (38) | 57 (50) | 94 |
| Respiratory infection† | 15 (15) | 27 (24) | 42 |
| Gastrointestinal disorder‡ | 11 (11) | 15 (13) | 26 |
| Malaria§ | 18 (19) | 30 (26) | 48 |
| August survey: | 46 children | 61 children | |
| Any illness* | 18 (39) | 32 (52) | 50 |
| Respiratory infection† | 15 (33) | 24 (39) | 39 |
| Gastrointestinal disorder‡ | 3 (7) | 9 (15) | 12 |
| Malaria§ | 3 (7) | 5 (8) | 8 |
| Combined surveys: | 143 children | 175 children | |
| Any illness* | 55 (38) | 89 (51) | 144 |
| Respiratory infection† | 30 (21) | 51 (29) | 81 |
| Gastrointestinal disorder‡ | 14 (10) | 24 (14) | 38 |
| Malaria§ | 21 (15) | 35 (20) | 56 |
One or more of the three key illnesses: respiratory infection, gastrointestinal disorder, or malaria.
Mother reported persistent cough, chest retraction, or acute respiratory infection.
Mother reported vomiting or diarrhoea.
Positive smear and palpable spleen.
Table 4 shows the results of the multivariate analysis to determine the relation between housing and the health of children under 5 years old. Although none of the unadjusted odds ratios are significant, all the relations are roughly of the same magnitude and direction. When access to safe water was controlled for, children in habitat houses were 45% less likely to have any illnesses (odds ratio=0.55, 95% confidence interval 0.34 to 0.75) than children in traditional houses. The incidence of respiratory infection was also significantly reduced among children in habitat houses.
Table 4.
Estimated odds ratios for effect of housing on illness in Malawian children under 5 years old
| Any illness* | Respiratory infection | Gastrointestinal disorder | Malaria | |
|---|---|---|---|---|
| Unadjusted odds ratio | ||||
| Traditional house | 1.00 | 1.00 | 1.00 | 1.00 |
| Habitat house | 0.64 (0.40 to 1.01) | 0.64 (0.49 to 1.13) | 0.69 (0.33 to 1.43) | 0.69 (0.36 to 1.30) |
| Adjusted odds ratio† | ||||
| Housing type: | ||||
| Traditional | 1.00 | 1.00 | 1.00 | 1.00 |
| Habitat | 0.55 (0.34 to 0.75) | 0.60 (0.34 to 1.06) | 0.60 (0.29 to 1.25) | 0.63 (0.33 to 1.21) |
| Water source: | ||||
| Unsafe | 1.00 | 1.00 | 1.00 | 1.00 |
| Safe | 0.40 (0.25 to 0.65) | 0.48 (0.26 to 0.87) | 0.31 (0.14 to 0.70) | 0.47 (0.23 to 0.94) |
| Fully adjusted odds ratio‡ | ||||
| Housing type: | ||||
| Traditional | 1.00 | 1.00 | 1.00 | 1.00 |
| Habitat | 0.56 (0.35 to 0.91) | 0.56 (0.31 to 1.01) | 0.58 (0.26 to 1.28) | 0.73 (0.36 to 1.40) |
| Water source: | ||||
| Unsafe | 1.00 | 1.00 | 1.00 | 1.00 |
| Safe | 0.46 (0.28 to 0.76) | 0.56 (0.31 to 1.02) | 0.29 (0.13 to 0.68) | 0.59 (0.28 to 1.26) |
| Method of waste disposal: | ||||
| Bush or community latrine | 1.00 | 1.00 | 1.00 | 1.00 |
| Private latrine | 0.95 (0.58 to 1.53) | 1.33 (0.73 to 2.40) | 1.11 (0.93 to 2.39) | 0.44 (0.21 to 0.92) |
| Knowledge of malaria prevention: | ||||
| Average | — | — | — | 1.00 |
| Above average | 0.37 (0.15 to 0.77) | |||
One or more of the three key illnesses: respiratory infection, gastrointestinal disorder, or malaria.
Generalised linear model adjusting for water source.
Generalised linear model adjusting for water source, occupation (farmer or wage earner), level of education (completing secondary school or not), knowledge of methods to prevent malaria (number of methods that could be named), and method of waste disposal.
The reduced rate of overall illness in children in habitat houses remained after adjustment for other potential confounding factors (0.56, 0.35 to 0.91; table 4). However, the effect on individual illnesses was not significant. Interactions between housing type and water source and between housing type and method of disposal of excreta were not significant.
Discussion
This study shows that the five year housing programme significantly improved the health of children under 5 years old. Children living in an improved house had 44% reduced odds of respiratory infection, gastrointestinal illness, or malaria. Access to a safe water source, having above average knowledge about the methods used to prevent malaria, and owning a private latrine were also significantly associated with lower odds of some illnesses. These associations were independent of the level of education and occupation of the head of the household. The size of the effect of housing was roughly equivalent for respiratory infections, gastrointestinal disorders, and malaria. Incorporating bed nets or ceilings into houses may increase the health benefits of better housing by reducing malaria further.
Our investigation has several limitations. Firstly, there is potential for bias in the selection of people into the housing programme by the habitat village committee. The similarity in the sociodemographic profiles between the two groups, however, suggests selection bias was minimal. Secondly, mothers could have misreported respiratory infection and gastrointestinal disorders. However, the hospital had a long association with the communities in this area, which has resulted in trust between the interviewer and interviewee. The final limitation is that disposal of excreta was improved in some traditional houses, with 38% having private latrines. We controlled for method of disposal in the final model.
The effect sizes in our study are similar to those reported for many other health interventions, such as improving water and sanitation, that receive more attention and financial support. Programmes in which simultaneous improvements in housing, water, and sanitation are combined with education on how to take advantage of these improved resources are likely to have the greatest effect on health.
Footnotes
Funding: The study was funded by Hermann Boozer-Noether Fund, Emory University, a Gangarosa scholarship NIH R29-HD33468, and Homeless International.
Competing interests: None declared.
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